How can you remove the interrupter (top bar) levers from the Giant Avail 5? I'm looking to gain a little extra space on my handlebars and I do not use these brakes, so I was wondering if anyone knew of a way to remove them.

The spec is:

  Brake Levers  Shimano 2300 w/ Tektro RL720 Top Bar Levers

To remove the crosstop levers from the bar tops you will have to:

Remove the inner brake cables

Remove the bar tape

Remove the brake cable housing between the main brake levers and the crosstop levers and the crosstop levers and the front brake / frame boss.

Remmove the crosstop levers from the bar (they should be held on by a simple clamp with 1 allen bolt).

Install new lengths of cable housing between the main brake levers and the front brake / frame boss.

Re-install the inner brake cables and re-wrap the bars


Change out shifters to be push-pull I have a Specialized Rockhopper 29 that has a Shimano Tourney RD-TX800 8 speed rear derailleur and a Shimano Altus FD-M315 2 speed front. The shifters installed on that are Microshift TS39-8R which are push-push. I am trying to replace both with push-pull shifters. Any suggestions would be great!!

I'm presuming you mean any shifter with a downshift thumb button and a trigger type index finger upshift release, i.e. most Shimano shift pods.
The hoop you must jump through here is that there aren't tons that are 2x8 by design. Most are 3x. Running a 3x shifter on a 2x front crank can be made to work acceptably, and many bikes have been set up that way, but getting it dialed great so that "shift lock" situations are properly unattainable can be a little tricky. Given that you have the option, I think just getting a native 2x shifter is better. One option for this would be the SL-M315 set from Shimano. That's the only set I'm aware of that has the clicks you're looking for and is a matched set.


Replace Regina valve with Presta I have recently bought an Italian bike that uses Regina valves and I need to replace one of the inner tubes. Since I don't live in Italy and can't find that kind of valve anywhere, I thought of using an inner tube with Presta valve instead since both are very similar.

Is there any reason why I should worry about replacing a Regina valve with Presta?

Reginas and Prestas are really close in size, they can easily be interchanged. If you do find that it rattles in the larger hole on mixed surfaces, you can always use the threaded Presta nut, just don't crank it down too much. The Regina valve also has a metal seat, so before using the Presta, I would get a bit of emery cloth and make sure that there are no burrs on the inside of the valve hole - Presta tubes have a double rubber seat, so they are more fragile.


How to fix contaminated brake pads? I recently spilled some brake oil on my brake pads and now they barely work, and they squeak (which I believe is normal for contaminated pads.)

It's at your own risk, doesn't always work, and may be a waste of time, but burning it out is the way to go if you have to do it. Looking past the global northy sort of time/money/risk/hassle equation, it's a pretty reasonable fix. I have no idea what the potential ill effects on braking power or trustworthiness of the pad material might be, but this approach is fairly common and major issues don't seem to result.
If possible, clamp them in a vise gently by the tabs, then use a heat gun or hair dryer to apply slow, even heat. Because the whole problem is the pad compound has some porosity to it, you're trying to heat it evenly all the way through. You'll get some smoke and are basically trying to heat it until it stops smoking.
Clean the rotor with something suitably nasty. In these cases of known mass oil exposure, it's good to take the rotor off completely and do something like a hot water and dish soap type bath, followed by thorough rinsing, followed by whatever sort of zero-residue reproductive harm spray. If it doesn't get a bath it can be hard to make sure everything is cleaned out of the windows.


Why do skinny tires require less pedal effort? Everyone knows (citation needed) that (at fixed rim diameter) tyres with smaller section require less effort to move around (at least on a paved road).

TL; DR.
Why?

A bit of context.

I always thought this phenomenon is due to the size of the contact patch between each tyre and the road. Notably, the area of this patch decreases when you decrease the tyre cross section. [This assumes that a tyre with smaller cross section will have a higher minimum pressure, which is generally true]. Friction is proportional to the contact area, QED.

However, I recently considered that friction (as almost everyone knows) would generate a torque that causes the wheel to spin faster [note 1]. So I had to come up with an alternative explanation.
My best attempt is this.
If tyre A has a smaller cross section than tyre B, tyre A will have a higher manufacturer pressure than tyre B, and therefore will be less subject to deforming.
In terms of conservation of energy, deforming a tyre continuously requires a fair amount of energy, and it's here that our precious kinetic energy goes when we stop pedalling and our expensive toys (or in my actual case, inexpensive toy) come to a sad halt. So tyre A sucks less energy than tyre B, and therefore requires less effort.
How can we put this in terms of forces? There must be an asymmetry in the forces near the contact point, causing a torque that slows down the spin of the wheel. Can you describe this asymmetry?

[Note 1. Friction is a force applied at the contact patch, with direction opposite to the direction of motion. Therefore, friction generates a torque that spins the wheel faster. For instance, in absence of any friction, a wheel would slide seamlessly without rolling.]

[EDIT. I apolgise for the sloppy formulation of the question. I edited to add clarifications where necessary. I opted for adding text rather than removing because some comments would otherwise look out of place]

Your opening claim:

  Everyone knows (citation needed) that (at fixed rim diameter) tyres with smaller section require less effort to move around (at least on a paved road).

Is actually not true. Your next claim isn't true either. The contact patch area for a tire will be nearly the same regardless of what width tire is used, for a given pressure. If I have a tire that is pumped up to 100psi, and the bike and me weigh 200lbs, the contact patch between both wheels will be nearly 2 square inches. Pressure is force divided by area.

Your third claim is also not true, as static friction is roughly proportional only to the normal force, and it doesn't even matter, as when the contact patch is touching the ground, it's not even moving!

By varying the width of the tire, while the contact area stays constant, the shape is different, notably the patch gets shorter as the tire gets wider. This translates to less vertical displacement of the rubber in the tire as the wheel rolls. Ross Millikans answer describes, the deflection in rubber is the primary source of tire-related rolling resistance.

It turns out, that for fixed pressure, wider tires have less rolling resistance than narrow tires.

The key element isn't the width of the tire, it's the higher pressure. It is much easier to make a small high-pressure tire than a wide one, for reasonable weights and costs. Furthermore, because making a high-pressure wide tire is more challenging, it may require measures such as thicker treads that increase the energy cost of tire deflections such that it is a net negative over more deflection of software rubber, and so on.

I'm not even going to address your torque theory because you are obviously confused as to the forces at play.


Am I ready for a century? I've just learned of a local century ride that is only 2 weeks away. I'd like to join, but not sure if I'm ready. I've been commuting by bike for the last five years. The last year of my commuting has been 18 miles/day that I do at least 4 days/week. Over the last 2 months, I've done several weekend rides of 40-50 miles, but I haven't gone over 50. I usually take one 10-minute break at about the 75% mark during these longer rides. After these longer rides, I'm tired and hungry, but feel like I could keep going at a leisurely pace after eating. Am I ready to leap to 100 miles? I don't have any days between now and the event where I'll be able to go for more than about a 30-mile ride.

The terrain for the century is flat, just like my normal biking.

Its not the distance, its the time on the bike.

Assuming this is not a solo ride, you'll be riding with other people either in a proper rotating bunch ride, or just on the same road/direction as them.  This alone will increase your overall speed by as much as 20%.

If you can be seated on a bike for 6 hours in a day, you can do this ride.

You will need to eat regularly.  For me thats "something" every hour, a gel or chocolate or a bar or some sort.  Or bananas, some people like them.

Water is also big - One plain water bottle and one with electrolyte mix added.  You will be able to top-up water bottle at the filling stations, for 161 km I'd expect 3-5 total stations along the route.  Check the map, but plan for one to be missing - its happened to me.

Filling stations are a rest point - you can get off the saddle while doing bottles, drink and eat, and go again.  Personally, 5 mins is plenty, but on a really long ride I like a 15 minute at somewhere over 50%.


E-bike rims: can I use them on my touring bike? I am touring with my MTB, now for 4 months.
I have been using really good Pacenti 29er rims, but just 2 days ago I cracked the rear one.
I am carrying a lot of weight and Pacenti (after I contacted them, great guys) made me notice that the rim even if strong for MTB is not made to carry that load.

I am thinking to replace the rims with E-bike ones, because they are actually made for heavier bikes.

Do you think it is a good idea?
The rim I would like to use is a:
DT SWISS Rim 545d 700c 28'' black 622-19 vl 6,5mm 36 hole simply eyed

Does that rim state a load? How heavy are you touring? Not much of the strength of a wheel come from the rim anyway, at least as regards vertical loading. MTB touring can put extra shock loads on a wheel compared to road touring.

A rear e-bike rim has a lot of stress on it, and not just from the unsprung mass of a hub motor but the shorter spokes. So it might be good, but the actual load could easily be less than a loaded tourer.

The e-bike I've ridden is about 30kg bare. That's less than the luggage when I went bike camping. The rider is almost always the heaviest part of the system.

The toughest wheels are probably those built for touring tandems. 40 spokes are common, 48 not unknown.


pairing a Duotrap sensor the the ibike Newton Is a Duo-trap speed/cadence sensor compatible with an I-bike Newton head unit? I can't make it pair up. I've tried keeping it a decent distance from other sensors and have tried resetting it, and changing batteries.

As long as the receiving end has ANT+ or Bluetooth Smart, also known as, Bluetooth low energy (BTLE) capability, the DuoTrap works fine. I have been using it with my Android phone for the last 2 years.

If your head unit is BTLE capable, that is enough. You do not need to pair as any other bluetooth device (e.g. BT headset) that would require pairing. The Bluetooth Smart devices sometimes actually do not pair as a regular bluetooth device.

You might need to try multiple times in order for DuoTrap to show up. Try rotating the tires for 10-15 rotations which should invoke the DuoTrap. Once it is active, it would appear on your phone or the head unit. Sometimes it requires 5 - 6 trials.


New bike chain for my mountain bike I have a hardtail mountain bike and recently I broke the 4 year old chain that I had on it. I’m looking for a new one and I’m wondering how many links I need for a 3x9(27 speed) bike.

Any bike chain you get will have enough links. The only thing to keep an eye on is the number of speeds it is for, which is the chain width. Just make sure you get a 9 speed chain.

There will be a range of lengths of chain that will technically work. A chain is too short if it can not reach around the big cogs on the front and back at the same time. You don't actually want to ever ride like that, but you don't want to break anything by just shifting into the wrong gear combo. A chain is too long if the deraileur can not take up all the slack when you are in both small cogs, or if the chain rubs up against itself because the rear pulley is too far back. Again, you don't want to go around riding in both small cogs, but if the chain becomes slack it can easily slap about and fall off.

The size of the range that will work depends on the difference in cost sizes your gears have, and the length of the derailleur cage. Mountain bikes generally have long-caged derailleurs to accommodate a wider range of cog sizes.

Often, the standard 114 link or so chain is an appropriate size for a mountain bike. If you put it on and it is not too long, you are good to go. But if you are really persnickity you might want to consider whether you want to be closer to too long or closer to too short.

If you are closer to being too short, the chain will actually be under more tension because the deraileur will be slightly more tight at any point than if the chain were longer. Tension in a spring increases as the spring is compressed. If the chain is more tight, it is less likely to bounce off the chainring. So if the terrain is very rough, you might benefit from a tighter chain.

On the other hand, if the chain is closer to being too long, you will be able to easily take a link out of necessary. Often if you break a chain the easiest way to fix it is to just remove a link and reconnect it. If you have sized your chain on the long side, this will be no problem.

As a side note, this is also why it is generally unreliable to just measure a new chain against the old one unless you know for sure that it was sized correctly and never had links removed.


Trading out folding bike seat post I currently have an older Dahon Mariner with a Telescope seat post. The third wheel that functions as the "third leg" (when the bike is folded) has broken off. To compensate, could I switch out the telescope seat post with a longer seat post. When the seat is dropped for folding, my intention is that the length of this seat post will resume the function of this third leg.

Is this possible?

My model does have a hole in the frame's bottom, allowing a long seat post to pass through (and function as a stand).

Update: Thank you for all the comments below. I am still looking to do this and now have the measurements of the current Telescope seat post. They are 34.2mm and 28.x respectively. The bike does have a small plastic shim between the frame and the bottom telescope seat post pole.

Update:
It was able to do it.

Yes

Of course it's possible, you just need to find a telescopic seat post on the market that is longer than the one you have.

Your measurement of your post might be a bit off though, I'm guessing that from your 28.x measurement, and the fact that I don't think 34.2mm is a seatpost size... not one that I'm familiar with anyways. In which case chances are your post is a 34.9mm, not a 34.2mm, and that something like this will do the trick:

34.9mm EXTRA LONG EXTENDABLE SEAT POST 530mm-730mm(21"-28") TELESCOPIC ALLOY


What is a narrow wide chainring and what are its benefits and drawbacks? What is a narrow wide chainring and what are it's benefits and drawbacks?
Also, is a specific chain or cassette required?

Modern chains have inner and outer links.  On a conventional chainring, all of the teeth are the same width, and therefore have to be narrow enough to fit into the chain's inner links.  This means that there's enough space for the chain to move about a bit from side to side on the chainring, which can cause it to fall off.
Historically this hasn't been much of a problem, since on geared bikes the front derailleur cage tends to stop it from falling off, and on single-speed bikes there's no chain slack or gear changing at the rear to cause chain-drop.
However, when you remove the front derailleur, but keep the rear derailleur (as is becoming common with single-ring setups), dropping the chain becomes more of a problem.  This can happen when changing gear on the cassette, or when a bump causes the chain to go slack momentarily.
Narrow-wide chainrings have alternating narrow and wide teeth that fit into the inner and outer links respectively.  This makes the chain more secure on the chainring and less likely to fall off.

A narrow-wide ring is only necessary if you have a single chainring at the front and a rear derailleur.  They won't work at all if you have more than one chainring at the front, since you won't be able to change gear.  You don't need a special cassette, but you might benefit from using a clutched rear derailleur (particularly on a MTB), which prevents the chain from going slack on bumpy terrain.
A well-established alternative to a narrow-wide ring is a chain guide, which behaves somewhat like a front derailleur in keeping the chain from falling off:


Why should I choose 36 or 32 spokes (or another number)? I have to change the rims of my bike and I have to choose between 32 or 36 (or 48 or any other variation). I never thought about this until now and I feel it's kind of a dumb question, but I don't have a clue if this has any perceptible impact or not.

So far, I understand that more spokes means a stronger wheel, but also more spokes means a little bit more weight. Despite that, a spoke weights almost nothing so I think that's not a practical difference to take into account.

Is there anything else? I ride a single speed bike mainly for city commuting, so is there any practical difference between choosing 32/36 spokes (or another number)?

Thanks a lot people!

Lower spoke numbers are primarily of interest to weight weenies (though for a given price, a lower spoke wheel will probably use a heavier rim offsetting the spoke reduction weight savings).

As usual, Sheldon is some good reading. There is also a whole book on how to build wheels well and design decisions, by Jobst Brandt, called "The Bicycle Wheel".

What matters for most people is using a good amount of spokes, good spokes, a good rim and hub, and putting them together well (and how they're put together) - pretty much any wheel is going to be bad if the wheelbuilder messes up/sucks.

Heavier riders often should go with a higher spoke number than a lower spoke number and tougher rims+spokes. According to Sheldon, it used to be that you'd run 36 front, 36 back then we started dropping. On a commuter, I'd emphasize durability, so I'd probably go with the more spoke option.

The best thing to do is talk to a good wheel builder and assess your individual needs. If you got to the point where rim wear was what made you replace the rim, chances are you're fine with whatever you had. If you're replacing the rim, make sure to use new spokes and make sure the hub is in good condition.


Lots of broken spokes on one bike, with different wheels I have a commuting bike I've had for a few years, and as long as I've had it it's frequently broken spokes on the front wheel. Eventually I got sick of replacing them, put it down to a bad wheel, and replaced it with another wheel I had lying around. This second wheel is a decent Mavic touring rim on a Shimano Deore hub, and it's done a couple of years of trouble free service on a previous bike.
Anyway, within a couple of months I got my first broken spoke and now it's the same pattern as before. Each time I replace I true the wheel up carefully and then check it again after a couple of days.

Over the last 20 odd years on several bikes I remember very few broken spokes- once on a loaded tourer, and maybe one or two MTBing.

So my question is this: Is there anything about a particular bike that might cause a lot of broken spokes- maybe forks slightly out of true or something?
It's a single speed with a reasonably high gear (45x16) and I am frequently out of the saddle but I can't think this would be any more or an issue than climbing hills on my road bike.

UPDATE

So a month or so ago I broke 3 spokes in 3 rides, and ran out of patience. After letting the bike sit in a corner for a bit I found a cheap replacement fork and swapped it over. A couple of weeks later and everything is good, so at the moment it looks like that was the problem- early days yet though I suppose, as it took a while for the original setup to start popping spokes and now the wheel might have a few dodgy ones in it.

Thanks for all the suggestions!

Are your brakes properly aligned? If they're off-center, every time you brake you'll generate a lateral force on the wheel that spokes absolutely hate.
How do you store your bicycles? Do they live in the garage or in the living room? If you live near the beach, the salt can cause corrosion and weaken the components.
Like the comments said, check the fork alignment. Since you stated that you had a wheel lying around that had never been a problem before mounting it on this particular bike, it leads me to think that there is something wrong with the current bike.


How much pressure can mountain bike tires take? I am thinking of buying a new mountain bike, but I'm unfamiliar with mountain bikes. That's why I need to be well aware of the pressure a mountain bike can handle. How much pressure can mountain bike tires take?

Says on the sidewall of a tyre. Mine says between 40-60psi. They also have it in 'bars' if you like to measure in that.

Check out an example here
http://www.chainreactioncycles.com/schwalbe-magic-mary-evo-mtb-tyre-super-gravity/rp-prod118255

Says max 50psi.


what are good training program for offroad racing? I am just getting into racing, and like offroad more. I'm also a runner so I'm used to training programs. I wondered are there any of these for bike racing, and specifically offroad?

If you new to XC (cross-country) you will need to develop three different components:

Technical Skill - This can include descending, switchbacks, riding drops (even hucking the odd drop - I have had to resort to this in many a race and even in a cyclocross race or two (a good way to get cheers from the crowd is launching yourself into a sand pit!).  You should also work at carrying speed through corners and over flat rough terrain. The more momentum you can carry the faster you will be for a given fitness level.
Endurance - Being an endurance sport, this is a critical component. Believe it or not it will help you with (1).  It is very hard to concentrate on technical sections if you are coughing up a lung and bleeding from the eyes.
Short term power - This is used to get up short steep climbs, to surge through technical sections and get you up those difficult step-up climbs.

1. Technical skill

If you are relatively new to off-road riding you should really focus on component (1).  This is your foundation, if you cannot efficiently navigate the terrain you cannot compete effectively.  Here getting out and simply riding is a great approach.  Try and deconstruct how you approach trail obstacles.  Experimenting with lines, body position on the bike (e.g., how you weight the wheels in turns, over drops and jumps) and attack strategy (e.g., maintaining speed or scrubbing speed for different obstacles.

Depending on the terrain of where you compete/live the amount of time you will need to dedicate will differ from area to area.  (For comparison I used to live and train on North Vancouver Canada, which have some of the most technically challenging trails in the world - so I spent a lot of time honing my technical skills).

Have a look through the SE questions for tips on riding techniques or ask around within your local community.

2. Endurance

Some dedicated mountain bikers may shudder at this suggestion, but the best way to build endurance is on the road on a road bike.  The environment is very consistent so you can pace much better than on the trails which tend to have a lot of periods of rest or inconsistent power output.  For me personally, I went from lower categories to begin reasonably competitive in Pro/Elite once I started putting significant time in the saddle on a road bike.

A quick search on SE will uncover lots of questions and answers about training on a road bike

3. Short Term Bursts of Power

While you could train this on the road, the trail is best for this component as you often need to be able to put down huge power while gingerly maintaining your balance and traction.  Training these components together is only possible off road.

Find some difficult off-road climbs and practice on them so you can climb them without putting a foot down.  My personal favourite was a steep 20% climb that had five large step-ups (each one as 2-2.5 feet high) in sequence. (Most rode down that trail, I preferred to ride up!)

It helped me to hone my focus and concentration, develop explosive power and develop determination to clear these obstacles. I first practiced after resting so I was at my best, then as I got more proficient I would ride harder and harder up to this section until I was basically full out the entire time with my heart in my throat.

Remember you can always breath on the descent (maybe)!


What is an equivalent or compatible chainring for this Deore XT "24-AM" chainring? I have a 2012 Mountain Bike with Deore XT.  While troubleshooting chain suck on my inner chainring, I figured I'd order a new chainring and replace it. The chainring only has  "24-AM" on it.  However, I ordered the wrong one:

Shimano XT FC-M8000 Double Chainring
24T, For 34-24T
ITEM #CG195A04

The holes didn't line up.  So I cleaned the old one and put it back on.

But which one should I be ordering?  My searches are returning the incorrect chainring that I ordered.  Does anyone know the specific part number I should be ordering?

Yep, that inner ring has go some nice shark-fin teeth. I predict your photo will be used in future questions about chain ring wear :-) The outer ring looks well- worn too.

An XT equipped bike from 2012 will have the M780 XT series crank which has four symmetrical bolts. The newer XT M8000 series has asymmetrical bolts.

I'm not sure if actual M780 rings are available but there are good aftermarket options for chainrings in general. All you need to know is the bolt-circle diameter (BCD) for the inner ring, which is easily measurable. You should be able to find a replacement with a symmetrical 4 bolt pattern in the tooth count you want at any of the larger online bike component stores.


Not sure which limit screw is H vs L I'm using a Devinci silverstone s.1 that's having trouble getting up to the highest/largest gear on the front.

I checked the tension and it didn't seem to make a difference. Read I should check limit screws next. Mine aren't labelled H and L but I thought I could figure it out from the chain's behavior but for some reason as I tighten and loosen each one I'm not totally convinced which is which.

There's one that's higher but closer to the lower gear and one that's vice versa.

https://www.dropbox.com/s/1s19rrlvpe9foqx/file%202015-07-29%2C%2017%2040%2037.jpeg?dl=0

Almost always the H limit screw is on the outside and the L limit screw is on the inside.


When is a wheel considered true? Generally speaking, how much runout can a bicycle wheel have and still be considered true?

The standard for what "true" means varies by mechanic and the intended use of the wheel.

A perfectly true wheel, in the mechanical sense, may not be attainable. Roundness and lateral runout are measurable to .001 millimeters using commonly available shop tools. Most mechanics do not consider that tolerance necessary, but as that is the limit of the tools, that is what I would consider perfectly true. However it requires 4 things:

Perfect roundness, measured by placing a gauge under the edge of the rim, and spinning the wheel.
Perfect lateral runout, or rather a lack of runout. This is measured by placing a gauge at the brake track of the wheel, and rotating the wheel to track the runout.
Perfect Dish.  Dish refers to the centering of the rim on the axle, or in some cases between the dropouts of the frame. This is measured using a truing stand or a dishing tool.
Perfectly even and balanced spoke tension. Measure using a tensiometer, the value here will vary significantly based on the type of spoke, the size of the rim, the material of the spoke nipple.  But the constant here is that all the spokes should have exactly equal tension.

I am well aware that the description here is of a mechanically perfect wheel, and that such a thing does not exist. It would require a perfectly formed rim, a perfectly machined hub, which perfectly drilled and finished spoke holes, and that each spoke be drawn from a perfectly pure metal at exactly equal and even dimensions.

The beauty and simplicity of the bicycle wheel is that while our manufacturing tolerances are not up to that standard, the design of a spoked wheel allow you to offset the tolerances in one area with spoke tension. If a rim is not perfectly true and round, more or less spoke tension can be used to pull it true and round.

So a "perfectly" true wheel might not exist, but a functionally true wheel is relatively easy. And "perfectly" true isn't necessary.


Chain Lube Compatibility? I bought the bike used, so I am not sure what chain lube was used in the past. I used Tri-flow Superior Lubricant once but may wish to experiment with other lubes in the future (Finish Line Teflon, White Lightning Epic Ride, Finish Line 1-Step). Are the different lubes compatible with each other? Should I use Finish Line 1-Step in between? I do not wish to degrease the chain each time, or for that matter ever, unless I absolutely have to. BTW it is a road bike, and it is now seeing about 70 miles a week.

You may run into issues if you apply radically different lubricants on top of each other.  You won't do any damage to the chain, but you might effectively use one lubricant to repel another.

I would cycle through the various lubes that you have mentioned you would like to experiment with during your normal maintenance window.  Every 1-2 months give the chain a good cleaning with a solid degreaser and then apply a fresh coat of the new lube that you would like to try.  You can then have discrete time periods where you know exactly what has been applied to your chain and a reasonable amount of time to measure the efficacy of the lube in question.

For degreasers you don't need to go crazy with spending a ton of money or time.  Simple green works wonderfully on a budget and there are bike specific ones (i.e. Park Tool Chainbrite) if you want to spend more.


bike fit calculator on competitivecyclist.com, accessing from .de I wanted to open
https://www.competitivecyclist.com/Store/catalog/fitCalculatorBike.jsp and got redirected to bergfreunde.de (outside the U.S. due to GDPR regulations)
Before I resort to VPN or similar - does anyone know an instance of this bike fit calculator available in Europe?

Looks like you're in Europe, and that website has chosen to reject your traffic because of that.  I've just tested from an AWS host in Frankfurt and seen the same result.
The text is

You're probably wondering why you've landed here of all places. Well, as of 25.05.2018, CompetitiveCyclist is no longer available outside the US due to GDPR regulations..."

then directs you to that .de site.
Essentially your collective nations'  GDPR requirements have been rejected, a case of "nah don't want to play with you" from competitivecyclist.com.   Upshot, you risk breaching your own nation's laws about GDPR by dodging them.
No matter how you cut it, this is a legal question about EU laws, and a technical question about web-based filtering.
This question has only minor tangential relation to bicycles or cycling, and the same fundamental question would remain if your destination website was http://llamapajama.com/   As such, this fails the "on-topic" test and will be closed.  Please don't take it personally.  You may choose to ask this on law.stackexchange.com - it is not really detailed enough to migrate as-is.


Different Derailleurs with different shifters I want to install hydraulic disk brakes on my bicycle, however I also need shifters as shifters and brakes are integrated on my bike.
I have 3 speed tourney FD TY 500 triple in front and Altus MD310 rear derailleur in the back.   Now I have trouble finding rear shifter, so can I use SL M310 Shifter with an RD 310 Derailleur?

Shimano 8 speed derailleurs and Shimano 8 speed shifters are always compatible.  So yes, you can use the 8 speed M310 shifter with your 8 speed derailleur.


Front suspension fork woes I recently bought a preowned Saracen Havoc 2000 (Team Saracen edition) and had to replace the original forks (Zokes branded double crown) as they were seized solid. Replaced them with an old but working set of RST Gila forks but now have a fair bit of flex where it moves a few mm's when rocked froward with full front brakes. Also makes a distinct knocking noise, as if something isnt fitting properly. Any help would be very grateful.

Sounds like your headset is loose. Have you properly rebuilt the stack order of the bearings, cups, shims and lower race?

Also make sure your star nut / top cap is pretty snug with the stem bolts loose, so you can fully seat the headset stack. Then tighten the stem bolts on the steerer tube.


How to indicate you are going straight? I live in a country where people drives on the right.

Say I am riding my bike like this:

    - main road
    vvvv
    vvvv      - narrow path
    vvvv      vv
    \    \   |  |
     \    \  |* |  <-- I want to get here
      \    \ |  |
       \    \|P |  <-- pedestrians crossing
        \       |
         \      |
          |     |
          |     |
          |   * |  <-- I am here, going straight
          |   ↑ |
          |     |
           ^^^^^
         main road

That is, I am going straight and want to continue like this in an intersection. For some reasons, people typically turn to the left in the crossroads (it is the main road), but I do want to go straight (a narrower path).

This means that pedestrians typically cross on point (P) without paying much attention to cyclists, despite us having preference. They check the road, though.

If I would go to the left I would indicate it with my arm. However, is there any way to indicate that I am going straight? I think on putting my hand straight but I am not confident that this will be understood by my fellow cyclists or pedestrians.

It's difficult to say without seeing photos of the road layout.  However, if the road itself continues round to the left, you should indicate right when you're leaving it.

In general, you should think about the topology of the road, rather than its geometry.  It doesn't matter that you're following a geometrically straight line; you're still leaving the road for a separate carriageway, and you need to signal this intention.

The default assumption for someone crossing the road is that you'll continue along the carriageway you're already on.

This said, of course, common sense should always prevail!  Never do anything that feels dangerous (for you or for someone else).


Stop Kickstand on Plate Shifting into Crank Arm I just installed this kickstand on a bicycle with a kickstand plate. The kickstand plate has raised edges at the sides, but the mounting part of the kickstand is a bit smaller. As a result, the kickstand can shift slightly in relation to the centerline of the bike. When it shifts out, the crank arm hits the kickstand while I pedal:

Is there some way to fix the angle of the kickstand mount, either using some kind of shim or just cranking down really hard on the mounting bolt? Or should I get a different kickstand?

The bike has an aluminium frame.

Kickstands are fiddly, and things tend to move unless really locked off. It's possible the bolt is loosening and the plate movement is the first symptom of loosening. To stop my bolt loosening, after adjusting everything to my liking I added a jam nut (a nut tightened against the already threaded part). This happens to be a self locking nut as that's what I had in the right size.  This is on a double kickstand similar to the one in the question.

Mine also came with a thin rubber pad to go under this plate. That helped, but when it broke I used a piece of inner tube cut to fit, which worked just as well.

Some of these plates are thicker, actually cast into a shape that should settle evenly across the chainstays. You could emulate this by attaching (probably gluing) a piece of plastic or aluminium to the plate, so that it sits between the chainstays. It would only need to be a few mm thick (around 1/4 inch) to prevent movement but would need to be nicely shaped and firmly fastened


Carbon-wrapped Aluminum seatpost? I have the seatpost shown in the pictures below. It came on a 2010 Specialized Tricross. It looks like Carbon fibre on the outside, but when you look at the open end of the tubing, it actually looks more like a thin layer of Carbon over a normal Aluminum tube.

I have two questions:

Am I correct that this tube is mostly aluminum with just a bit of carbon outside? If so, why would they even bother adding the Carbon? Just for show?
If it is mostly Aluminum, would it be acceptable for a long bike tour? From a durability perspective, that is. The reason I ask is I just got a new bike that came with a pretty basic metal tube with a hard to adjust seat clamp and less offset than this Carbon-wrapped one. I would prefer to use the Carbon seatpost from my Tricross since it has the offset I'm used to and a nicer seat clamp that's a bit easier to adjust fore/aft position and tilt separately.

1) It's for show, just like the carbon fiber insert on my Leatherman Skeletool CX. See this question.

2) It's fine for touring provided its in good condition. However, you may still want to get a different seatpost depending on the adjustments available on this one.


Gear up-shift not smooth When I am pedaling hard and shift to a larger sprocket, the shift is not smooth or sometimes doesn't happen at all. Sometimes even double up-shifts don't work. There is no problem shifting when I test for it without riding. What could be the issue?

On ground, after shifting, look at your bike from the back. The sprocket into which you have attempted to shift, and the pulley in the derailleur should be aligned. If the pulley is more to the right than sprocket, you need to get it aligned to the sprocket, by tightening in the screw on shifter or on the rear derailleur. As you tighten the screw, you should see pulley moving horizontally.

If that does not help, other problem might be that your chain hanger is bent, but that happens much less often, and typically after some crash or hard hit on the rear derailleur. If that is the case, taking your bike to LBS sounds like a good idea.


Quick-release seat slipping down My bike's quick release seat has been slipping down recently.
I noticed when my (pro) biker friend remarked how low down the seat on my bike was, and helpfully readjusted it for me. Biking became easier. Yesterday, while biking, I noticed that biking was difficult again, so dismounted and checked the seat -- it was way down again.
So I fixed it.....but what can I do to make sure it doesn't happen again?

You have to make sure that you're actually tightening the quick release down - it should leave an imprint on your hand when you close it down.

If you put a product like frame saver in the frame, you'll need to tighten it down extra since that makes seat posts super slippery.

See this thread as well.


Can an IGH have the same maximum overdrive-ratio as a crank-sproket setup? Is there an IGH that gives one the maximum overdrive-ratio that one might get with a 39-53T crankset and a 11-34T freewheel? If not, what is the mechanical roadblock in making one ?

If we use the Sheldon Brown Gear Calculator set to metres development (although any other unit will work adequately), we see that the range for a 39-53 x 34-11 system is 2.5 to 10.4 metres developed per crank revolution, yielding an overall range of 416%.

The widest range options from various companies are the Shimano Alfine 11 hub, which has a range of 409% - essentially the same - and the Rolhoff Speedhub 500/14, which has a quoted 526% range.

Compare to a Sturmey-Archer AW three-speed hub, with an overall ratio of 178% based on its stated ratios of 1.33, 1.00 and 0.75.


Is there a benefit using SPD SH-51 cleats over SH-56? With SH-56, you can remove your shoes easier.
I wonder if there's a benefit of using SH-51 over SH-56? Does 51 help produce more power (less loss)?

SH56 releases when you pull up on the cleats, ironically defeating the largest benefit you’re trying to achieve by using a clipless pedal system. Using SH51 allows you to benefit from that upstroke.
Before anyone tells me that “you can’t pull up!”, try pulling up more than you push down while sprinting  out of the saddle, clipped in. You can actually pick the entire rear end of the bike up off the ground with each leg by pulling up hard enough. Try doing that with flats!
As you said, using SH56 will make it easier to remove the shoe from the pedal, defeating another purpose of clipless systems: better foot retention. Racking up the pedal tension while using SH56 in an effort to make release more difficult defeats the purpose of SH56.
SH56 is a crutch for inexperienced clipless users who haven’t mastered the clip-out movement yet. That’s it. Arguably, it is best to never use it so you completely remove the pull-up-to-release instinct from your body. Simply turn the tension down as a beginner. You’ll pop out in a crash, don’t you worry.


Loud "thunk" sound each time my shoes pass the 1 o'clock position with both shoes Folks, I need a hand. Does anyone know of a bike mechanic that can diagnose problems via FaceTime or another audio/video app?

I ride strictly indoors (I’m in Iraq) and there’s a knocking coming from the crank/BB area that I haven’t been able to fix.

Equipment: Cervelo S3 (rim), Sram BB30, Rotor 3D+ cranks, Rotor 54/42 oval rings, Sram eTap, Speedplay Zero stainless steal, NOT ceramic BB

Each time either shoe passes the top of the crank circle I get a good 'thunk' sound.  I can hear it and I can also feel it resonate in the carbon frame, no matter speed, RPM or watts.  My cleats are on tight, pedals on tight, I removed the cranks and reinstalled them to spec, bolt rings are tight.  I put my finger and turned both bearings using my finger tip.  Both bearings are still ultra smooth.

IDEAS?

My bet is that this is caused by the bike rocking side-side as you shift body mass and pedalling forces. The noise is caused by the trainer shifting or perhaps the bike frame shifting on the trainer. The vibration or noise is coming through the frame and feels like it is emanating from the bottom bracket area.

Its sounds like you have ruled out the noise coming from the bottom bracket / crank area. I would spin the crank by hand with the bike in the trainer to make sure of this. Also grab the crank arms and push/pull in all directions to check for any play or movement in the bottom bracket.

If you have a smart trainer check that its axle does not have any play.

Try sitting on the bike and shifting it side-side, as if you were sprinting, but without rotating the pedals. Can you replicate the noise this way?

Can you ride the bike off the trainer to see if the noise occurs then also, or goes away?

Can you recruit a friend to listen and try to locate the source of the sound while you ride the bike? (Being careful to not get kicked in the head or tangled in the drivetrain of course.)


What are the round things near the main front cog? This bike in this picture has two rollers near the front sprockets. The chain goes through the lower one and not the top one. I've no idea on their purpose vs other bikes that don't have them and notice that they make a lot of noise.

Questions

What are they, what are they typically used for?
Are they needed?
What would happen if if remove them?

Please refer to the image below

They are chain keepers.

Back in the day before narrow-wide chain and 1x transmissions, the front mech/derailleur was a great way to keep the chain on the chainring.  And given bikes had two or three chainrings the front mech was necessary for changing gears.

However MTB riders liked to bounce around a lot, and that could still "throw the chain" which removed your propulsion.  This was not ideal.  The two rollers pictured work more like guides than like jockey wheels.   They are there to guide the chain, and may or may not have teeth.

These would be more common on bikes with full suspension, where the chain tension changes as the shock compresses.  Your bike appears to be a hard tail, so only chain slap from bouncing or landing can cause a derailment.

Given this bike has a derailleur protector and relatively small rims, I think its a kids bike and the guides are more about protecting the bike from mistreatment rather than keeping the chain on during technical sections.

As for "chain goes over bottom roller and clear of the top roller" its because the plate in the back is maladjusted and needs to be rotated a few degrees anti-clockwise as pictured.  That it still rides okay as shown proves that this tensioner is relatively unnecessary.  You might be able to tap it into position using some gentle percussive maintenance, though this may upset the bottom bracket.

If you remove the two guide wheels it would leave the chain a bit long, so two or perhaps four links might need removing.  If you remove teh whole plate, that will move the Drive side bearing cup inboard and possibly change the chainline.  I'd leave it in place personally once its adjusted.

They make a lot of noise because the bearings are probably dry.  So remove, service and reinstall would be ideal.


First cyclocross race - how to choose and set up the bike I have never raced but there is a cyclocross race at a park near me next weekend.

All it said is some sand and some drop offs.

I would like some advice on selecting a bike and setting it up.

I have Bianchi Cylcocross Concept and Salsa La Cruz Ti.
They are both Ultegra and greared the same 48/39  12-28.
Both cantilever and weigh about the same.
The concept is my workout bike and the Salsa by daily banger / commuter.

The Concept feels faster but the Salsa feels more stable.
I also feel like the Salsa can take a crash better.
So my thought is the Salsa.

I take it they race with cleats?
For a first race should I cleat.
I am comfortable with cleats.

I have touring tires on them now but I have some Conti 32 Twister.
Would they be OK?
Would I run them at max pressure?
I weigh 165.

I also have a Niner Air 9 Carbon single speed mountain bike with carbon fork, disc brakes, and tubeless.
I am not comfortable on big drop off on my cyclcross.

I rode the park on four set ups.

With 32 mm it was just too fast for me.
There are some downhills with rocks that I would need to run at max pressure and even not in a group picking my line I was not comfortable.

The Air 9 was super stable but not very fast.
I rode the park 15 minutes each direction and if the long hill is uphill then the single speed is not geared correctly but I am pretty sure they will have us ride down that hill.

The Salsa with 38 mm small block at mid pressure felt stable but still has a speed.

As far as cleats.  I would not want to ride the downhills without em.  Getting bounced hard enough that need bike attached.

Most cyclocross tires are 33-35mm and with tubulars (glued to the rim) many will run very low pressures (20-22 psi). I run 35mm clinchers and get to each race early to pre-ride a lap or two to dial in my pressure, typically will run 28-34 psi depending on how rocky the course is, I don't want to pinch flat, but really like the lower pressure as each lap it typically gets more and more muddy and you want the grip, especially on the off camber sections.

Cleats or no cleats is going to be more about your comfort getting in and out as you will get on/off the bike to carry up stairs/run-ups, through sand pits and barriers. This is about speed getting unclicked and clicked back in and right up to speed. Search on You Tube for cyclocross mounting.

You did not mention disc brakes, but with rim brakes, the sand will mix with the mud and wear your brake surface. If short and fast I'll ride the sand pits, if running I carry my bike, so go with the lighter bike.

Many courses have run-ups and barriers to carry your bike, so go with the lighter bike.

Many races have a 'pit' area for you to leave extra wheels, or even a different bike, so bring both bikes, get there early take a lap on each and race the one you like better. Put the other bike in the pits and switch if you get a mechanical or pinch flat. If this happens far away from the pits, you must run the course with your broken bike - you cannot leave course and take a shortcut, fix or switch and then get back on course.


Fixing a flat - how to find the piercing object? Just had a flat and having problems finding the thing that pierced the tube in the tire. Normally I just run my fingers around in it, until I found it, but this time everything looks O.K.

My experience is though, if you do not find the object, another flat will happen soon ...

I know the trick with searching for the puncture on the tire in the same space where the hole is on the tube. I even flipped the tire so that the pattern is inside, but nothing to be found.

It's a mountain bike tire, and the hole in the tube is very tiny.

The object that pierced the tire and tube may have been left behind or it might be embedded in the tire but hidden in the rubber. This can happen with small pieces of glass, wire, or thorns, especially in thicker treaded tires such as those found on a mountain bike. When the rubber of the tire is compressed against the ground the offending object will stick back out through the inside of the tire, re-puncturing the tube and then as that section of the tire loses contact with the ground the object conceals itself again. It's almost like a bee's stinger.

First thing I would do is just slap another tube in the tire. If you have another flat in the same place then you might have something still stuck in the tire that isn't immediately obvious. If you know how the tire was oriented against the tube, inspect both the inside and the outside of the tire around where you think the puncture occurred. Do it under bright light and look for small cuts in the tread. Use a pick or tweezers to dig around in any cuts you find to ensure that nothing is hiding in there. If you find something, great! Problem solved. If not it may be coincidence.

I'm also an advocate of patching the inside of tires after anything more than a pinhole puncture. If you have a cut that is more than a millimeter or two, you probably want to boot the tire. Otherwise you've got a weak spot where debris is more likely to penetrate the tire and pop another tube. You can buy tire boots, which are expensive, or you can use the glue type (not glueless) tube patches. I've had great success with tube patches on the inside of tires, even with road tires and mtb tubeless setups. Keep in mind that this wont work on cuts bigger than a few millimeters.


Can I use a bike for commuting 10km everyday at Jönköping (Sweden)? I'm a French student going to Sweden for one year and I would like to know if I could use a bike to go to school even in winter for less than 150€ (or 1500 SEK).

Is it possible without having a bad time when riding and or will I fall every five seconds due to icy roads?

If it's possible I would like to know which type of bike should I use and if I have to add accessories like studded tires or tire chains.

Here's an average weather of the city:
https://weatherspark.com/y/78217/Average-Weather-in-J%C3%B6nk%C3%B6ping-Sweden

And some details about my route:

Start altitude:                  102 metres
End altitude:                    111 metres
Maximum altitude:                129 metres
Minimum altitude:                93 metres
Distance:                        5.1 km
Total ascent:                    54 metres
Total descent:                   45 metres
Maximum gradient ascending:      5% at 1.7 km
Maximum gradient descending:     6% at 0.6 km

As long as the bike paths and roads you'll be traveling along are reasonably well cleared of deep snow, this would be no big issue.

You can order basic Schwalbe Winter studded tires cheaply (around 40euro a pair) from Bike24. You should probably be able to find a basic used bike for 110 euro.

Studded tires aren't strictly necessary for winter riding, but they do provide peace of mind on days with a freeze-thaw cycle.


Regular squeak from rear wheel My back wheel is giving out a periodic squeak as if the wheel were buckled and rubbing on the brake.  Only, it's not buckled and it's not rubbing on the brake.

It's one squeak per revolution of the wheel, regardless of speed, but each squeak is the same (short) duration even if I move slowly.  It doesn't matter whether I pedal or coast.  The wheel isn't rubbing on the frame and if I gently brake through several revolutions it still squeaks while I'm braking.

I asked a bike shop about it a while back and they couldn't find anything but after all the routine adjustments it went away for a while.  Now it's back.

If I get off and turn the wheel by hand there's no sound.  Even if I lean on it and roll it around it's quiet.  It seems that I need to put all my weight (an my panniers and gym gear) on it to make it squeak.  I guess that's why they couldn't find it in the shop.

My best guess is uneven spoke tension might allow some of the spokes to shift and rub slightly.  I've looked them over and don't see any wear and I'm not sure how I'd make a definitive diagnosis there.

What could it be?  What else can I test?

It could be the freewheel or hub bearing causing the squeak but this should not be the case as both are lubed,  or should be. More likely is as you mention a spoke.
Sometimes spokes squeak at the hub end as they flex.. Try rubbing in some grease or putting on a drop of oil on each spoke fitting at the hub end to see if it cures it,  just ride the bike and let the lube take effect.
Of course a spoke could also squeak at the nipple end too as it flexes slightly in the wheel,  the only way to address/lube this end properly is by removing the tyre etc and applying a tiny drop of oil to each nipple. Don't let it get near your braking surfaces though.


What are the main differences between road saddles and mountain saddles? There are thousands of saddles out there. Some are designated as road saddles while others are mountain saddles. However, the marketing copy does not seem to describe the difference between the two types, even between two similar models (for example, Selle Italia seems to have an SLR for road bikes and an SLR XC for mountain bikes).

In general, what are the main differences between road saddles and mountain saddles? What, if any, are the potential downsides of using a road saddle off-road or a mountain saddle on pavement?

There is a lot of variation across models of saddles even if you stay within one genre (eg only consider road or only consider MTB).

However, you'll find if you look at popular racing saddles that MTB saddles tend to be shorter. This is because in singletrack you're very frequently moving onto and off-of the saddle. A longer saddle might interfere with the "body-english" that some MTB riders use.

That said, if a saddle fits, it fits. That is the most important criteria. Everything else is a distant secondary consideration.


Replacement guide for different cleats? I'm planning to replace my wellgo 6 degree float to look keo grip 9 degree float. I've searched for cleats replacement guide online but most of them only caters to replacing identical cleats. I'm pretty sure these 2 cleats have some minor differences. How should I go about it? Or should I go to a bike fitter for cleats fitting again? The latter is probably my last resort as it will cost a lot just for cleats fitting.

Wellgo make a variety of aftermarket replacement cleats and pedals for various systems, including Shimano's SPD and Look Keo.  They should be (almost) completely compatible with the equivalent system's branded cleats.  I've personally used Wellgo Keo-compatible cleats as a replacement for Look-branded cleats, and there were no issues at all.
Assuming you're talking about these Wellgo 6-degree cleats then the Keo equivalent 9-degree float should be a drop-in replacement.
The way I change cleats is to take a Sharpie and trace around the base (the heel-facing end) of the old cleat before removing it, and then align the new cleat to that line when installing the new ones.  It shouldn't require a fitter, since the plastic is as identically shaped as they can make it.
(Just to be clear, trace along where the cleat meets the shoe, as indicated in this picture.  This shape is dictated by the shape of the pedal, and any compatible cleat must have this exact shape here.)


How should I gear a 12" wheel on an adult bike? Background: A couple years back I built a chopper with a 26" front wheel and a 12" rear wheel. It was a lot of fun, but I had to pedal like mad to get anywhere. Unfortunately I could not find a rear cog small enough or a front cog large enough to get me somewhere useable on long rides and ultimately had to increase the wheel size to 16". The size increase worked out great, but I want to try to build a new chopper with a 12" (if not 8").

Are there cogs small/large enough out there to make this work?

My other thought was to weld a bottom bracket shell to my seat post with a multi-speed chain ring and chain one sprocket to the front and the other to the rear. Would this work? If it would and this seems like the right way to go, what sprocket would need to be connected to what sprocket?

Using an 8 or 9 tooth BMX cassette hub will get you into the normal useful range for singlespeed gearing pretty easily with a normal large road ring. 53-9 on a 12" gets you about 70 gear-inches for example, which is a common choice for fixed/singlespeed road bikes. Most present-day freestyle BMX rear hubs would work fine. (Most are 9t, some are 8 - 8s wear out fast and are considered going too far by many.)

Using a 56t tri ring and a normal 12t cassette cog gets you into around 56 gear inches, which would probably be fine for a chopper. 56t rings, while not exactly common, are easy to get. Origin8 makes a 56x130. If this gearing worked for you it would probably be a cheaper route.

Since you mention going on longer rides with it, the good answer may just be to run it with the Shimano Capreo group and a 56t ring, giving you the benefits of a derailer drivetrain. I'm pretty sure the Capreo derailer should still clear the ground on a 12", but you might want to corroborate that somehow before doing it. It may not on an 8".


Does master-link size matter? I recently got this chain master-link for my 21 speed bike but it turns out that it's really meant for a 24 speed drivetrain. Does this mean that the master-link won't be good on my set up? Or that it'll still work just fine? I really don't want my bike to be affected or the shifting to get harsher.

Like so many other things in life, size does matter.

You need to have the master link matched to the chain size (which depends on the number of speeds and manufacturer (which is basically campagnolo versus everyone else)). For example, a master link for a 11 speed chain will be too small for a 7/8/9 speed chain.

Manufacturers generally suggest you use their chain closing mechanism (Shimano's special rivets, KMC/SRAM's master links, Campagnolo's special rivet that needs peening, etc.), though many people mix and match master links across brands without issue.

In this case, you'll be fine -- 7/8 speed bikes use the same chain (you have a 3x7; the 24 would be 3x8), so you can install the link on the chain.


Vibration from pedals at slightly higher speeds? I've bought myself a new bike (BTwin Riverside 120) and I've taken it out for a couple of spins as of yet.. When speeds go above, say, 20-25 km/h (12-16 mph)  (I'm giving a rough estimate based on what strava told me), there's a distinct vibration of sorts that I feel when I'm pushing onto the pedal to propel the bike forward, and the lagging foot (I really don't know the appropriate word, if any that exists) doesn't feel any vibration even at high speeds. The vibration does not happen on speeds around 10 km/h (6mph) at all though.. What can be the reason for this? Is that normal?
Pardon me for being stupid but I'm just speculating here, can it be that the air cutting through my shoe soles is causing me to feel the vibration on my foot? (I may be pedalling wrong).
The saddle height is lower than what it needs to be for my height because the bike's primary use is done by someone shorter than I. I say that because my foot is mostly not parallel to the ground when I'm pedalling, it's mostly pointing up.

You may be feeling vibration coming from worn bearings in either the pedals or bottom bracket. Something this is only discernable when applying greater force to the pedal and crank - which would explain why you feel it in the down stroke but not return stroke.
Manually turn the pedals feeling for excessive resistance, 'notchiness', clicks or play. Do the same for the cranks. If you can slip the chain out of the front derailleur cage and off the chainrings it makes it much easier to feel any problems when turning the crank, because there is no drag or vibration from the chain.


How many speeds will fit on a wheel? I have a cassette style wheel. How do I measure whether it will take a 7, 8, or 9 speed cassette?

I would go to a bike shop, or take some hub you already have.

As far as I know, there are only two sizes: one for 7 and one for 8/9/10 (these are the same, just the distance between the sprockets is progressively smaller to fit).

And if your data-processing capacity and confidence are good, you can dig some info here:

http://sheldonbrown.com/cribsheet-spacing.html

and also

http://en.wikipedia.org/wiki/Cogset


What can I do to keep my rear derailler in good condition when commuting in the snow? In the winter, it seems that whatever I do, my rear derailleur stops functioning after few weeks of commuting in light snow. Ice always gets in there somehow, and the chain refuses to move the wheel, skipping.

The bike always stays outside (covered but unheated at home, outside at work) all the time, and I tried to bring it in for a melt every day, and every week. This seems to make the problem worse, so that even if there is no snow and the freewheel looks fine, the freewheel skips. Maybe rust has gotten in there, now.

What can I do to prevent the freewheel to skip after few weeks of usage in snowy conditions?

I'm not interested in internal gear hubs for now, as they are much more expensive.

There's not much you can do aside from cleaning your drivetrain often and thoroughly. In the winter, ice is far less of a mechanical issue than is rock salt.

You may indeed have some corrosion in the entire drivetrain by this point, not just the deraileur, or possibly just dirt if you're lucky. I'd do one major cleaning at this point, and see if that takes care of the problem.

I'd remove the chain entirely and let it soak in addition to cleaning the deraileur and cogs. Failing that, you can get a chain-cleaning device and use that. It's not as thorough, but still better than nothing by far.

After that, I'd clean my drivetrain once every week or two, depending on conditions. Also keep in mind that you may need to lube more often. None of these are really a big deal, once you set up a space (an old towel on the floor will do it).

If none of this helps, it's time to look into possible mechanical causes. Riding on ice and snow, I often find pebbles and grit in my drivetrain, more than in any other season. Possibly you have a bent tooth or other mechanical issue? You can give the drivetrain a good inspection while you clean it, looking for any problems.


Shifters/brakes won't fit on bullhorn bars I have a KALLOY UNO HB-005 580 mm handlebar and a shifter with brake combination, Shimano Alivio ST-M310. I have a Sora derailleur and crank set. I got as a gift a bullhorn Origin8 Bully Bullhorn 6061-T6 Handlebar 400mm wide 31.8mm clamp.

The problem is that the shifter's mounting ring is not enough wide to get on the bullhorn at all, I can't imagine how to put on it and if I manage the first centimeters, than there is a corner. How can I fit the shifter/brake on the new bullhorn or do I have to change the shifter system?

If only the mounting ring can be changed I would be happy. I opened the sifter but the bolt which holds together the brake lever and shifter is blocked mechanically (doable). Is there another brake lever that has a wider ring and can be replaced with the current one, so I can keep the shifter?

Edit

I measured the old and new set:

KALLOY - 22.20[mm]
Origin8 - 23.88[mm]
Shimano Alivio - 22.38[mm]

Update

Would  it be a structural integrity problem, if I grind 1-2mm of the inner wall of the mounting ring?

I would advise against the grinding idea.  You might be okay if there's enough meat left on the ring, but these are part of your braking system, you really don't want that to fail.  Imagine an emergency situation, or even an intersection at the bottom of a big hill.  You squeeze the levers hard and the mounting rings break, your brake cables go slack and you can't slow down or stop.  Even assuming only one ring were to break, you'd have maybe half of your stopping ability remaining which could easily lead to injury (or worse).  The breaking of the ring could also startle you enough that you lose your grip on the handle bars.  Not worth it.


Why is my new front wheel not spinning? Today my front wheel got flat. I took it for repair and when I went back home cycling it was very hard.  It felt so heavy and that was not normal for speed 4, when I changed down to speed 3, 2, 1 it was also spinning slowly and feeling so heavy. I stopped the bike and spun both wheels, the front new wheel was spinning very slowly; almost not moving and the back older wheel was spinning fine and fast, so I realised there was a problem with the new wheel. I would like to know what the technician did wrong?  How can it be fixed?

I want to know because when I go back to the bike shop I wish to be aware of what has happened so he doesn't fool me.

The most likely problem is that the brakes are rubbing.  If you pick up the front of the bike, hold your head near the brakes and spin the wheel you shouldn't hear any noise from the brakes.  If you do, then the brakes are rubbing and that's the first problem to be fixed.  To be honest, I'd guess that's 99% likely to be your problem.

If you have fenders, and the new tire is larger in size than the old one, then there may not be enough clearance for it; that can also be detected by listening for rubbing sounds.

If the brakes are fine and nothing else is rubbing, pop the wheel off the bike and try spinning the axle; if it doesn't spin freely then that means there's too much pressure on the bearings.  (Note this is really unlikely if the shop only changed the tire.)


Scratch or damage on carbon frame I found this 'scratch' on my carbon frame on top of the front derailleur. Not quite sure when or how it appeared. Could this be more than a scratch?

That's just a light scratch. No issues.

if you are worried that the carbon-fiber composite has been damaged by an impact or scratch, the abrasion is far too shallow for that. It has not even penetrated through the paint.

It's not a crack because cracks do no start in the middle of frame tubes, they propagate from edges or holes.


FSA crank + BB combination too tight I have a bike here fitted by OEM with:

FSA Omega Adventure MegaExo crank
FSA BB-4000

No maintenance or mods done around BB area on this bike. If you are curious it is Pinnacle Neon 5 2019-version. Only around 5000 km on it from new.
The crank never really spinned well from the start on that bike. Without the chain in place it does at most 1/4 of a turn before coming to a stop.  I have been asked to look into it recently. I initially thought to write it off as FSA lower-end cranks being garbage in general... But eventually took it apart to take a look. The findings are interesting...
The NDS crank arm has a self extracting mechanism (like most FSA Crank arms do) and against the expectations it worked pretty well. I was able to pull of the NDS crank arm and then take the DS arm out with the axle (no mallet needed). I checked the BB in the shell without axle and it appears to be silky smooth. I did the usual TLC on the BB and crankset:

Removed BB from the shell
Cleaned the threads on BB, shell, self extractor nut, spindle and retaining bolt.
Greased the threads
Greazed the axle
Put everything back together

The crank spins silky smooth until the point when I tighten the NDS crank arm retaining bolt. FSA spec says 40-50 Nm. The crank stops spinning properly around 10Nm which is way too low to be secure in my view.
There is a wave washer between NDS crank arm and the BB face which is supposed to preload the bearings. This wave washer is fully compressed and looks flat at 10Nm. Anything above that and I am compressing the bearings. By the time I reach ~40Nm the cranks is back to the same state as pre-maintenance - it does about 1/4 turn without chain in place.
From the situation described above I am very confiden that the issue is simply with the NDS crank arm sitting too close to to the axle centre when tightened to correct torque setting. Bearings are overloaded and cannot spin free. Could be a manufacturing tolerance issue. There is definitely no alignment problem as the crank arms spin well when the retaining bolt is at 10Nm...
I am really surprised as to how bearings did not get damaged after riding ~5000km in this state but this is off topic.
Any ideas on how to cure this problem? Anyone has experience with FSA cranks?
If there were any spacers, I would start by removing them to allow more room for that crank arm and wave washer, but there are none... Either none came with the crank, or not fitted by whoever was assembling it. And rightly so - spacers would have made it tighter.
To aid the discussion here is an illustration from FSA manual (not the same but very similar crankset:

Ironically in the same document I find this (which clearly does not help):

UPDATE 2021-05-11
Measured the frame with vernier caliper. It's 67.93mm so pretty close to expected 68 (allowing for the tool and measurement accuracy).

Ok, so I got this sorted!
Thanks to everyone for input. Posting the solution here in case someone else is facing the same problem.
The answer is inspired by @Nathan Knutson 's post.
@Nathan mentioned a transparent scuff washer... And I did not remember seeing one when taking the crankset off. So I took it all apart again and specifically looked for it. There is indeed a transparent plastic (or nylon?) washer that was tightly pressed into a small groove on the inner side of the NDS crank arm. It was flush with the surface and did not come off when I was cleaning the crank so I assumed it is part of the crank arm and not removable.
Now I removed that washer and it freed about 0.3mm for the wave washer to expand. Asessembled, torqued to recommended setting, crank spinning well and I can clearly see that the wave washer is no longer flat - it now serves its purpose and preloads the bearing as intended.
There is a slight concern that removing the scuff washer will make the wave washer rub against the crank arm and scuff it over time but for me this is a minor concern as this crankset is cheap and I was close to replacing it with Shimano or SRAM dub or anything else with adjustable preload... Now it will serve a little bit longer before being discarded.
For all those who assumed misalignment of the BB shell - this is a valid assumption but wasn't my case.


Where can I find a bulb for my vintage 70's generator light? I currently own a 60's/70's vintage light for my bike. I have it attached to my Trek 820 series 26" mountain bike at the moment.

The light worked perfectly fine until one day when I broke the bulb inside. The bulb was marked on the side being 2.5v, even though I know for a fact that the generator on the back wheel puts out about 6 volts.

I have tried several bulbs from Radioshack, and none work or are as bright as the previous bulb inside my Reynold's light. Is there anyplace on the web where I can Find such a replacement bulb? Are there any stores that mint have what I'm looking for? I tried Home Depot also, no luck there...

Thanks in advance!

This is nothing more than a standard dynamo front bulb - 6V 2.4W is what you really need (the rear is 6V 0.6W). Most Northern European bike shops carry screw-in Halogen versions of them for 'Union' brand headlamps of your vintage:

If you are not running the rear light from the dynamo then you need a 6V 3.0W bulb in the front. (2.4W + 0.6W = 3.0W).

The problem with the simple two-bulbs-in-parallel circuit is that if you remove one light (e.g. a broken wire) then too much current goes through the remaining bulb and it blows.

Think about it, go to the bike shop when you have a problem with the bike, not the electronics store or the car-parts store or the aromatherapy store. The staff in the bike shop do know a thing or two, they have heard of bicycles running dynamos and, even if they don't have spare dynamo bulbs to hand, they do have a supplier that they can get them from for you in a reasonable period of time for a price that will not cover their time dealing with your enquiry.

I suggest you visit the LBS first, they may only be able to get you the 2.4W version, if they can get you the 3.0W version then get it and a flashing light for the back. In that way you will have a rear light that works when you stop, more light up front and less likelihood of blowing the bulb (because there is no rear bulb to blow).

Alternatively, get a new front headlamp unit for the dynamo, these may be special order from the bike shop, however, such a unit will have niceties such as a better reflector and lighter construction.


How to commute to work on your bike and dress up I have a question regarding commuting to work on a bike. I recently moved to a new location because of a new job. The drive to work is roughly 15-20 minutes depending on the traffic (no freeway or highways). About a month ago I got a new bike the Giant Revolt 3. The location is a bit away from the city so I've noticed a lot more people ride bikes here.

My question is, how do you commute to work on a bike? My bike ride to work is about 7 miles, half of it is probably on the side of the road, and the other half is on a bike trail that takes me all the way to the office. Like most people, I have to wear a dress shirt and pants with business casual shoes. Don't people get sweaty? Wouldn't your clothes get wrinkled if you put them in a backpack to change later? There is a guy that always take bike rides for lunch and when he comes back he's drenched in sweat. How do you avoid these problems?

The reason I want to start commuting is because About 5-6 years ago I lost a bit of weight and I've been having chest pain problems which went away after I lost the weight (and I'm only 23), now they're coming back because I'm sitting in front of a computer most of the time.

(feel free to change/add tags if necessary, thanks).

I've recently started commuting to work 3 times a week and my commute is about 8 miles each way. I've found if I roll my clothes rather than fold them and pack just before I leave, there are no creases when I get to work. I always put my shoes at the bottom of my bag, then trousers rolled up then shirt. I leave my ties in my desk draw and leave my suit jacket at work.

It takes me about 45 minutes to get to work and I make sure I take the last mile easy so I don't arrive out of breath. I then spend about 10 minutes in my cycling clothes (making sure the kettle is boiled and quickly checking emails) to give me time to "cool down" before I go and get changed in to my work clothes. I've found I'm completely "dry" by then but if not I use wet wipes. Liberal use of deodorant and I'm good to go.

On the way home I just do the reverse. I attack the route home faster for a work out as I can have a shower when I get home.

I believe that as you get fitter you'll sweat less too, so it gets easier.


Is there a All-In-One Bike that I can use for several types of riding? Is there a bike, which can be used for several types of riding? By this, I am referring to commutes, tours, cross country, off-road mountain biking, trailing especially.

The bike should contain the major quality of several specifically designed bikes. By this I mean the following:

Road Bikes: Lightweight, speed, ergonomic
Downhill MTBs: Rigid Frame, High performance suspension and Tires
Cross Country: Comfortable (on Long tours)

For me, I have an habit of using a MTB for most of all the activities I mentioned above and most of time, this is not an comfortable experience over long run.

So, the question is simple Is there a bike, which contains all the qualities in one?

In general you can get an very good all-around road bike, or a very good all-around mountain bike.  To get a single bike for everything there will always be trade-offs in areas like weight/durability; speed/traction; etc.

That said - many people own one bike and use it for everything.  If I had to drop to one bike I would buy a 29"-wheel based front suspension mountain bike with the following:

suspension front fork with lockout
disk brakes
rack and fender mounts (and a rack and fenders)
a spare wheelset

In my mind the spare wheelset is key - that way you can run a high pressure slick on one set, and then switch to a knobbie without the hassle of swapping out the tires on each wheel.


What maintenance does a front suspension fork need? I've just bought a used bike on eBay, its a 2002 Marin Bobcat Trail. It has 'In-Sync 266' suspension forks. This is my first suspension bike so I need some guidance in the use and maintenance of these forks. I can't find any user manuals or anything online. Perhaps someone has one they could send me? Failing that, here are the questions.

The fork feels very soft to me, but I am a heavy rider and I'm not used to suspension forks. How do I know if the fork is working 'right'?
What maintenance can/should I carry out on the fork?
On the left hand side (only) there is an adjustment knob labelled just + and -. What does this do and how do I know how to adjust it? Why is it only on one side?

That should be enough to be going on with, any answers very much appreciated.

For guidance, my last bike was a 1995 Marin Bear Valley SE, hardtail, no suspension. AWESOME bike that served me well for over 17 years, until it was stolen a few months ago. I did all my own maintenance and I consider myself a competent cycle mechanic, its just that my skills are relevant to 17-year-old bikes :)

The fork is "right" if it has the right "sag", that is, if it lowers a bit when you get on the bike. The right sag is no less than 10%, no more than 25% of total travel, for a regular bike (non-downhill, non-special-purpose);
Basically three "areas" must be addressed on maintenance:

Cleaning the inside, for removal of old oil/grease, water, mud, grime, rust, etc.
Caring for the damping elements, which could be elastomer, coil, air chamber, open oil bath, etc. That would vary a lot depending on the type;
Lubing the telescopic parts, which are responsible for the movement of the fork. Depending on the type (open oil bath, for example) the damping oil and the stanchion-lubing oil is the same, so it is serviced together.

This is called "preload", and probably increases or decreases the compression of a coil spring or elastomer. That is for the adjustment of "sag" according to your weight, being equivalent to say that it lets the fork "harder" or "softer".

As far as I know, the brand of your fork is on the cheap end of the quality spectrum, so it's possible that it doesn't work perfectly, or at least not as perfectly as higher-end models. I'd say that, if it "works", meaning if it saves your body (hands mostly) from shaking over bumps, then keep it, even if it has too much sag, or some play, or is not so light. But if it "gives up" working too soon (say, you go over bumps and it barely moves, or you feel the bumps hard on your hands), than it is well worth to change it for a better model.

If you decide you'll keep it and service it yourself, I'd recommend purchasing some grease/oil (check which you'll need for your specific model) that's made specifically for bike suspension. A lot of lubricants I've inadvertedly used in the past contained some sort of adhesive (to stick to the metal surfaces and protect them), and the lubrication became gluey as soon as the bike hit some dusty path. On the other hand, fluids intended for suspensions or hydraulic systems tend to expel impurities and keep flowing nice over time.

EDIT: I've found some photos and reviews online, of your fork (search words: "sync 266 fork"). By that (plastic upper caps, dust "accordions" around the telescopes) and by the reviews description (mtbr.com), I'd say it is a low-end fork, thus without any hydraulic valves inside, most probably elastomer or coil spring. You should be able to disassemble it at home "no-fear".

Hope this helps!


Can you buy bulk shifting/brake cable for road bikes? Is it possible to buy bulk amounts of shifting/brake cable for road bikes? It would be nice to just have a spool of wire that you run onto your frame and then cut off only as much as you need.

A Google search for "bike cable spool" doesn't really result in much, surprisingly...

How do bike shops deal with this? Surely they don't buy individual packs of cable for every bike do they?

I know you can buy cable housing in bulk, so I was surprised when I couldn't find similar for just the cable...

The problem that you'll likely run into is the stop in the lever/shifter ends. I'm not aware of any systems that will accept bare cable at this end:

If you wanted to pair your spool of wire with some sort of crimper (or go all out with some sort of mold/press), you could make your own - but investing $3,000 - $30,000 on some machine that melts metal on the end of the cables probably isn't worth your while.
I don't have much experience with bike shops (I buy most everything on eBay), but I would think they have boxes of these cables packaged in bulk like this:


Does it matter how far backwards you can spin your drivetrain? If I spun my cranks backwards on all my previous bikes I would get a good few spins out of them, maybe as many as three or four on one of the bikes. But with my current road bike I can barely get a full rotation out of it.
Does this matter? Is it an indication of the friction within the drivetrain, or just the way that some setups work, either by design or as a side-effect of how they're designed?
I'm guessing that it's the rear hub that slows it down, but there's no restriction in speed when riding fast or freewheeling that I can detect, and no excessive noise. It was an almost brand new Cannondale Optimo and the BB has been serviced.

I don’t think it’s a good indicator. Plenty of viscous lube and lightweight (-> low inertia) components can easily mean that a high end bike spins worse than a 20 year old bike with dry and rusty bearings.
The most important thing is friction under load, which is hard to measure. But you should make sure that bearings spin with little force (to make sure they don’t have excessive preload), that they don’t have any play and that they turn smoothly through the full 360°.
To check if the hub’s free wheel mechanism has excessive friction, spin the rear wheel. If you have quick release axles, make sure they are not excessively tight. To check if it’s the bottom bracket bearings (more likely) take off the chain and spin the cranks. If it’s neither of them it has to be the rear derailleur.


What parts of 12-speed drivetrains are compatible between brands? Now that Shimano has released their own 12-speed MTB drivetrains (SLX and XT), I have the following question:

What parts of these drivetrains are compatible between Shimano and SRAM?

I would guess that chain, chainring and/or cassette (assuming wheels with the respective freehubs) would work with the rest of the drivetrain being made by the other brand while combining shifter and rear mech from different brands wouldn't work.

Is this correct?

The key issues relating to compatibility is the width and spacing of the cassette sprockets (and chainrings), chain design and the design of the ramps and pins on the sprockets and rings that facilitate shifts. SRAM followed Shimano up to 11 speed but I believe they diverged at 12 speed.


Can I take a bike into central London on the Underground? I'm coming from Canada and will be riding in the London-Edinburgh-London randonneuring ride which finishes in Loughton. The London Underground info. shows that I can take my bike on the Central line and shows it until Leyton. Does this mean I have to get off at Leyton or can I continue on to Bank station? Do the allowable stations mean that's where I'm allowed to board or can I continue?
Thanks - Terry

You can take your non-foldable bike only as far west as Leyton on the Central Line and only off peak. The map here shows where cycles can travel on the underground. The green lines are the permitted routes. Where a station is on the route it has access for cycles. The Central Line is a very deep line so once underground it wouldn't be possible to get a bike in and out of a station.

It is a 10km cycle from Leyton to Bank, use the Cycle Journey Planner to get the appropriate route.

Another option would be to cycle from Leyton to Maryland (~2km) and then catch a Greater Anglia service to Liverpool Street. Once again nonfolding bikes are restricted during peak hours. This is a National Rail overland service but a tube day pass and oyster card would be valid as long as the stations were in the purchased zones.

There are also plenty of overland options, it may be better to complete the whole journey via the overland if available. Unfortunately maps such as this one show all the overland lines, and is relatively simple to read, but it does not give any indication of geographical distance. Pick up an A to Z street directory (out dated these days!) or do some searches and use the Journey Planner around where you are staying or entering London to see if there are any better or closer options.


Could two identical bikes require different pin positions for front derailleur cable routing? This is a multiple choice question, with just two choices. But please explain a bit.
Shimano's Dealer's Manual of some front derailleurs shows a "converter judgment tool".

Suppose you work at a bike assembly plant, tasked with assembling 1000 identical bikes.
The front derailleur comes with two, and only two, positions for routing the cable.
The pin underneath plate B in the figure below has two positions. The two positions (also appearing in the figure above) can only be seen if you remove the plate B.

Assuming the converter judgment tool is so fragile it will be unusable after the first use, does your boss give you 1000 converter judgment tools or just one?
A. As many "converter judgment tools" as frames, because the converter judgment tool is supposed to solve issues of tolerances in manufacturing the various parts, or
B. Exactly one "converter judgment tool". Since all the bikes you are assembling are absolutely identical. It is enough for you to invest a lot of time to choose between the two routes, and henceforth use that pin position for the remaining 999 bikes.
Depending on whether you answer A or B, this means:
If B: if a bike is shipped (during pandemics or at other times) in a box, the amateur mechanic assembling the front wheel + handlebar and tuning the bike will normally not need to order the converter judgment tool.  The pin position is the same for all identical bikes. It would be a rather serious mistake if a bike slips through with an incorrect pin position. The FD cable arrives already attached and tensioned, even if the tension may be inaccurate.
Another way of asking this question: could the mechanic at the bike assembly plant who worked on your particular bike have made a mistake and chosen the wrong pin position?
If all identical bikes require the same pin position, then one would expect a seasoned mechanic to have carefully chosen the pin position. Possibly, this can be determined during the design of the bike, and the designer can already specify the pin position before the first frame even exists.

For the most part every bike model will use the same position for the converter.

What the converter essentially does is give some adjustability to account for different points of origin off the BB shell area for the final run of exposed cable before the BB anchor, because the derailleurs that feature converters have an anchor point whose lateral coordinate is very close to directly over the pivot of the actuation arm and are thus more sensitive to how the angle of approach of the cable affects the total throw of the cage, compared to traditional derailleurs where the anchor is more off to the side of the arm pivot.

Because these derailleurs are sensitive enough to this angle to require all the fuss of a special tool etc, it's conceivable that in some cases that small variances in layup, the exact position of a cable guide hole in the BB shell, etc, could cause enough variance for different bikes of the same model to need the converter set differently. And it would be very likely for this to be overlooked in a factory assembly setting.


how to increace the friction between tyre and road While designing a bicycle what are the designing factors to be considered to increase the friction to give more efficiency to the cycle.And what are the other factors that can be considered while designing.my interest is to design a modified bicycle to improve efficiency and decrease man power

Reducing friction (or grip in layman's terms) would cause your wheel to simply spin in circles when you pedal and you would fall down.  Increased friction between the tire and the riding surface is the goal of nearly every tire manufacturer.

You could easily coat your tire in oil to accomplish the lower friction you are talking about.


Rear cassette replace 11-30 with 11-32, or 11-28? I have an 11 speed 11-30 rear cassette that I would like to replace but cannot seem to find an 11-30 anywhere.  Can I safely replace this with an 11-28 or an 11-32 without replacing my rear derailleur?

If the OP's bike has a short cage Shimano rear derailleur, then officially, the maximum cog size is 30t. Going down to 28t is definitely fine, but going over 30t is not technically OK. Shimano's compatibility specifications are known to be conservative, however, so in practice, a 32t cog should work. I would caution against exceeding the maximum cog size by more than 2 teeth, unless you also install items like Wolf Tooth's RoadLink, which extends the derailleur hangar.
I would very cautiously disagree with @BenStokes that you must necessarily lengthen your chain. The OP may find that your chain is long enough to handle the 11-32. I recently installed a pair of oversized pulley wheels on my road bike. The official recommendation is indeed to resize the chain, but in practice, my chain had adequate length to shift into the big ring, big cog combination. I would suggest that the OP can very cautiously try to shift into this combination in the bike stand (and not on the road). If the chain is at all reluctant to make the shift, stop moving the crank immediately and re-size it. With the amount of force you can generate with your hand, then even if the OP's chain is too short, the OP won't damage anything if they stop promptly. (This is why I suggest not trying this on the road; your legs can produce enough force to do considerable damage.)
Conversely, if the OP's bike had a medium cage Shimano derailleur, then technically, the smallest large cog is 30t, and an 11-28t cassette isn't officially compatible. However, I am actually running an 11-28 with a medium cage rear derailleur right now.
I have no current experience with SRAM or Campagnolo, but I believe the same recommendation (that you can exceed the official specs slightly) should hold true. I used to run a short cage Campagnolo 10s rear derailleur with a 13-29 cassette, i.e. exceeding the maximum tooth count by 4. I did this on advice received on forums that this could work, depending on the bicycle. Again, I would prefer to recommend that people don't exceed the maximum cog count by 4 teeth.


Good Gloves to Prevent Ulnar Numbness I recently noticed that towards the end of my 6.4 mile ride to and from work, my hand and arms began to numb.  A friend recommended I try cycling gloves, so I purchased these from Amazon.  They do seem to lessen the numbness, but not prevent it entirely.

What's more, it doesn't feel like the pads hit my palm in such a way that it removes weight from the middle channel of the wrist, though the gloves seem to fit my hands without any slack.  How do you identify the right fit for preventing ulnar numbness?  And is it ever completely preventable, or do I just need to live with it to some extent?  If I am still feeling numbness, should I send the gloves back?

A little more information would be helpful. Are you riding a road bike or hybrid, or what? How tall are you? What is your inseam? What size is the bike?

Without this information, the best I can do is:

1) 6-7 miles isn't a long ride. If you're getting numbness in such a short distance, something is probably wrong.

2) It could be the fit of your bike. Hands get numb when they carry too much weight. If your bike is not the right size, or if it is set up incorrectly, this may cause you to put too much weight on your hands.

3) It could be your fitness. If your core (abdominal and/or back muscles) are weak, you could be compensating by putting too much weight on your hands.

4) It could be a combination of #2 and #3.

What can be done to fix this? It depends on the cause. See if your bike is the right size for your body. Online fit computers can help with this. In addition, consider strengthening your core. If you ride a hybrid, consider some new grips.


Rear deraileur maintenance / adjustment I have a 9 year old road bike with Shimano 105 groupset (approx 20 000 miles).  I clean the deraileur as best I can but have never taken it apart or replaced anything in it.
Recently, when I use the small chainring, the top jockey wheel seems to rest on the chain and cassette.  It makes some noise but shifting is pretty much unaffected.
Are you able to give me an idea of what the issue might be before I start disassembling things or ordering new parts?  What the expected lifespan of a deraileur?

As mentioned in the other answer, the first thing that could be tried is adjusting the B-screw.  This adjustment will vary the gap between the jockey wheel and cassette. Clockwise rotation of the B-screw moves the jockey wheel away from the cassette, widening the gap between them.  Conversely, loosening the B-screw counterclockwise, will move the jockey wheel close to the cassette.  Proper position for setting the B-screw is when chain is on small chainwheel and large rear cog. Measuring from tooth tip to tooth tip there should be a 5-6 mm gap between jockey wheel and large cassette cog. An Allen key of 5mm should just squeeze through the gap is how I determine my adjustment. Even though your shifting seems unaffected, the jockey wheel should not interfere or touch the cassette in any way.


Do dry wheel bearings increase drag? My kid trailer I have had for a few years has, in the past few weeks, been noticeably harder to pull.  I checked it over and I found that not only are my wheel cones are a little loose, that I can spin the axle with very little resistance.  When I say little meaning I can give the quick release lever a light flick and it will spin 4 or 5 times easily with the wheel in the vertical orientation (off the trailer).  I'm assuming that this is because the bearings are dry, and since anything I have rebuilt myself, the grease (park tools polylub 1000) will give some drag to keep it from free spinning.

I have pulled it for hundreds (if not thousands) of miles to this point without really any problem.  This summer it has been in the rain twice (~4 miles), but I noticed this new drag before.

Trailer (shaped object) is a Pacific Voyager II sold through Toys-r-us (best that I can tell).  I don't know the service history (assuming none) and I'm the 3rd owner.  When I got it I replaced the tires on it (20" Kenda road tires) and keep the pressure high (50lbs of 55lbs max).  At around the same time I also upgraded the hitch system to a standard Burley one so I no longer have the spring in the system causing tugging.

If your wheel can spin freely around the axle, there's two scenarios here:

You've got super awesome bearings that have held up really well and still rotate freely.
The bearings are actually really tight and not moving at all and the wheel rotates on the axle itself.

Either way, since you mention the cones are loose, you should pull apart the hub and check the bearings. Look for dirty grease and see how the bearings/races look. Clean and repack if necessary.

New grease will always add a bit of friction, but as it breaks down and heats up (during use) it usually becomes more viscous, therefore reducing friction.


Would a seat post mounted back rack act like a rear fender? Specifically I want to know if the right one would stop the rider's back from getting splattered with rain. That way it does double duty as a fender and a rack.I want a light duty back rack for day to day cargo. If I am getting bulky groceries or doing the laundry I can always use a backpack.
I like the minimalist lines of some of the ones I have seen. They suit my bike.

I'd say it depends on the length of the rack you're going to attach.

It's all about the physics - the water droplets, when they detach from the tyre they move perpendicular to the perimeter of the wheel. If the rack is long enough, the droplets that might reach your back are hitting the rack (acting as a mudguard).

The ideal situation would be when the rack reaches to the furthest rear point of the wheel. Then only the droplets travelling vertically are not covered by the rack.

However when the rack gets shorter, the more droplets travel to the front, thus direction of your back.

Short story long - have a look at the picture:

black is the bicycle (obvious)
red is the rack
blue is the  most front-travelling droplet that might hit your back

I hope you get the idea.