Coming back from a Serious Injury Some I am not a frightful type guy, and this is still kind of new but last week I took a bad spill and am unsure what to do about it in the future.  For the record I am 51 years old and was training for a triathlon.

I was just on my way back from a ride, having dealt with heavy winds on the way out.  I was traveling about 20-22 mph when I went off the road into the grass.  I attempted to get back onto the road by lifting my front wheel kind of a front wheel bunny hop.  Instead I caught the edge of the road and rotated down.  I was clipped in, so I landed hard on my shoulder and subsequently head.

The resultant injury was broken ribs, clavicle and a punctured lung.  I will be out at least three months.  I was wearing a helmet that prevented any head injury thankfully.

Frankly I am a bit scared.  What should I do to avoid injury in the future?  I have taken similar spills as a kid, and not really been injured.  It really sucks as I am just 5 weeks from my tri, and I was going to crush my time goals.  Now I will have to go back to the drawing board for training three months from now.

That's rough. Rotten luck and you have my sympathy.

When you say "as a kid" am I right to think not fully grown? Because little kids start closer to the ground, don't weigh as much, and don't tend to be going as fast, but crash a lot. Teenagers are a different matter: good reactions but poor judgement and the size and speed of adults, but they're quick to heal and fractures tend to be less severe as their bones are more flexible.

Did you by any chance suffer any kind of hand injury? Apparently breaking the clavicle is common coming off a bike if you put your hand down, but that's instinctive (I was lucky recently that I was still holding the flat bars when I hit the ground, and was a lot slower).

You may never know exactly why you came off this time (why you got to the grass in the first place). Maybe you were pushing your speed right to the limit of the grip on a bend and hit a bad bit of road, or instinctively dodged something. Maybe you were very close and the wind shifted. Maybe tiredness contributed. Trying to hop back onto the road was a bold move that I couldn't carry off, but many people could and you know your own skills. Maybe it would have worked but for continuing bad luck.

When you get back on the bike, you'll have to build up gradually. You won't be as fast, as flexible, or as fit (even if the medics allow you to do some trainer work as part of your recovery - you may even be encouraged to at the later stages but). Go out with a group, but a slower one, and people you trust not to push you too hard until you're ready - buddies are great for confidence. Start with decent riding conditions - if you're in the Northern hemisphere that's easy as you'll be out in the summer. Know that you've got to look after yourself. And see a good physio, preferably one who specialises in injured athletes.

Right now you're not in a good place, but as you get back out and ride you'll be able to make a full recovery from the mental as well as the physical trauma.


Replacement for Suntour NCX-410 crankset on commuter bike? I've had a 2007 Marin Larkspur which I have been using as a commuter and recreation bicycle for 3.5 years. For the past year, I've been slowly learning to do my own repairs and upgrades as they have come up. I recently upgraded the chain and rear cassette (SRAM PG-830 and PC-830, respectively).

Now it seems like my crankset is acting up. My middle chainring is quite worn and with the new chain especially it tends to skip very easily on hills. Based on Marin's specs, the bike should have a Suntour NCX-410 crankset, and I've been told that I can't simply replace the chainrings on this part. I've done some reading (Todd Downs, Zinn books) about cranksets and bottom brackets while cross-referencing with Marin's specs. I think my bike has a sealed cartridge square taper bottom bracket, but I don't know anything about its size, etc.

I'm looking to this community for a recommendation on a good-quality but budget crankset with replaceable chainrings that will either work with my current bottom bracket (if it doesn't need to be replaced, how to tell?) or that would work with a modest bottom bracket purchase as well. I'm looking for the best value given that long-term cost of upkeep is a large factor in my upgrade/repair decisions.

Thanks in advance.

Unless your bottom bracket is giving you issues, you shouldn't need to replace it.  Sealed cartridge bottom brackets have quite long lifespans.

The link you provided indicates that the current crank is designed for a 113mm long spindle (that's the LL113 bit), which is a fairly common size.  My personal favorite square-taper crankset with replacable rings is the Sugino XD-350, which is also designed for a 113mm spindle.  It's basically a drop-in replacement for the cranks you have now.


Cassete spacer for CS 7800 and WH 7900 Should I use spacer on CS-7800 who is being installed on WH-7900 ?
Or just install the cassete without 0.5mm spacer ?

Cheers and thank you..

Shimano Dura Ace wheels do not require the extra spacer behind the cassette that every other wheel requires. So, no the 7900 wheel should not require a spacer with the 7800 cassette.


Pain in the lower back and neck during cycling I am new to cycling (road biking). When I bend my back to hold the handlebar and maintain a low position, to avoid head winds, I feel a pain in the lower back and neck.

Is this normal?

Do we get used to the pain, once we start practicing long distances regularly?
If it is not normal, should I do something to avoid the pain?

Your bike fit should not cause you pain. Back pain, neck pain, knee pain, hand pain, elbow pain, etc are all signs of a problem; they shouldn't simply be ignored, and probably won't just go away on their own. Muscular soreness after pushing extra hard is really the only kind of pain you should get.

I suggest that you:

Get the bike fit to you. Many bike shops offer this as a service, and may discount it significantly with a new bike purchase. This will probably entail assessing your flexibility and changing out the stem and adjusting the seat position.
Increase your flexibility. Hamstring stretches, etc, so that you can bend at the hips more. Personally, I do this while coasting on the bike after I've warmed up.
Strengthen your core. Planks, etc. So you can hold that position better and longer. As long as you make an effort not to lean heavily on your hands, this should improve as you ride more.
You may also want a different helmet and/or sunglasses. Anything that blocks your vision when looking "up" will tend to force your head to tilt back more. You don't want a visor/peak on your helmet when riding "down low" on a road bike, and you may find that thick rims on the top of sunglasses are also a problem.

From your description ("when [...] in a low position"), I'm guessing that you're putting yourself in a lower position than you're flexible enough to really do right, and compensating for that lack of flexibility by curving your lower back too much and bending your neck back.

There's a lot of debate about ideal bike fit, but in general you want to be:

Bent mostly at the hips, with a bit of spine curvature (not too much).
Your upper back tilted back so that your neck doesn't have to bend too far back, which is facilitated by less lower-back curvature.
Shoulders down/forward and elbows slightly bent. Not leaning too heavily on your hands. You should be able to take your weight off your hands for a bit without shifting your position.

On a road bike, you'll typically spend most of your time with your hands on top of the drops, so that's the position to make the most sure you're comfortable in. But you want to be able to be reasonably comfortable down in a lower handlebar position ("in the drops") for windy situations, downhill sprints, etc.


iPhone ANT+ bicycling apps that can import a GPS track? Does anyone know if any of the popular iPhone ANT+ bicycling apps have the ability to import a GPS track?

I'd like to start exploring some of the local trails/routes a bit - I've got .gpx tracks for some, but don't know of any iPhone apps that will both allow the import of the file AND feature any sort of ANT+ tie-in. I normally use digifit with speed/cadence and HRM sensors... I've got a GPS track of where I AM, but really wish there were some sort of approximate "turn by turn" for following some of the trails/routes, especially the urban ones that are not clearly marked.

I use Motion-X as my tracking app and it can certainly import GPX and then navigate from it. It supports some ANT+ (at least HRM).

Additionally the OpenStreetMap wiki has a good list of iOS apps comparing their functionality.


My bike brakes are lethal, help! I've got an old Raleigh Winner (1980s 10 speed racer) which is perfect in almost every single way for what I need it for (I got given it free, it's very speedy and also looks cool).

However, the brakes are dodgy to say the least. I had to take the rear brake off entirely the other week as the bit that holds the cable in the brake lever fell off (mildly alarming as I was trying to stop at the time!). I haven't replaced it yet as it was basically useless before, should I bother?

In the dry, the front brake is incredibly squeaky but very effective (I adjusted the toe the other week?) In the wet though, it just won't stop and it's bloody frightening! I think the brakes might be cantilevers (they've got two wire spring things on pivoting arms) but they're so useless in the wet! Admittedly, I think the brake blocks are probably as old as the bike, but why are they so bad in the wet compared to the dry? Freewheeling to a stop is nearly as effective (and when/if the brakes do eventually bite, they whole bike vibrates and judders, it's very odd)! The tyres seem to be fine as well.

Would some new brake blocks and/or cables solve the problem (the rims are steel, which apparently makes a difference)? I'm a student so I'm hardly drowning in the dolla and also a bike n00b so I'm not great on the technicalities. What should I do?

Cheers.

There are a lot of things that could be wrong and a picture of the bike might help confirm this, so I'll just make a list of some things to check and what they need (this is by no means comprehensive):

1) Brake pads -- if they're old, they've likely dried out. Replace them. Needs a hex key. Make sure they're also hitting the rim and not rubbing anywhere. Also, clean the rims with rubbing alcohol (or if you're a student, vodka).

2) Brake cables -- these can rust or the lining of the cables can be worn out making them not work properly. You need a housing cutter/dremel + awl + file to do this.

3) Adjust the brakes. They look like single pivot sidepull brakes from google images, and you can find directions to adjust them here. You need probably a hex key and maybe a screwdriver. Also, make sure the caliper is secured to the frame.

4) The judder could be lots of things -- theres a certain amount of judder on all bikes. Could be a loose headset (is the fork moving when you hold the front brake and try to move the bike?). Or it might go away if you fix 1-3.

My suggestion is that if you don't know much about bikes or don't have someone to help you is to take the bike to a bike shop to get it checked out and see what needs repair, since you may not have all the tools you need to fix it or the expertise. You need both brakes in case one fails.


Wheel performance in cross wind I'm looking to buy a pair of Mavic Cosmic Carbone SLE or Mavic Ksyrium SLR.
The Cosmic's are 50mm height, Ksyrium 25mm.

I'll only be using the wheel for racing.

How do they perform in cross wind. I'm thinking about performance (watts used) and also handling, can I control the bike in a group.

My simple logic tells me that the smaller rim, would of course be best choice in side wind. But then again, I suspect that the aero wheels perhaps might not just have been made for still winds?

I'll start by saying that finding solid data on wheel aerodynamics is tricky at best.  Some of the better sources are worth taking the time to read in full, and provide much more information than I can provide here.  For example, see the article from Tour Magazine [1] that covered the Mavic Cosmic Carbone SLR (similar, but not the same as what you asked about).  Also see the testing done by Roues Artisanales [2] where he reviews many wheels including some older Mavic Ksyrium models.  Of course, tests such as these are expensive and time consuming, so we typically can't find wide ranging, scientific test data across all of the current model wheels.

Having said this, there is also a lot of rider data that can guide you as to the ride-ability of these wheels.  For example, on the weight weenie forums [3] SpinnerTim said that the Mavic CCs "have strictly traditional deep-rim stability issues in cross winds. These ride the way deep rims like mid-decade 404s or Lightweight Standards rode when V-sections were the rule...".  In short, the CC SLE will provide some aero benefits from the front, but isn't the best in cross winds.

The Ksyrium is kind of the opposite.  It isn't a particularly aero wheel, but will also have pretty normal / average performance with cross winds because there isn't much there to catch the wind anyway.

For improved aerodynamics at various wind angles, I would encourage you to look at some of the more modern wheel shapes.  Things like the Smart ENVE System or the Zipp Firecrest.  Even the Mavic CC 40C is likely to provide better cross wind handling than the SLE [4,5].

[1] http://www.tour-magazin.de/services/qtr/epaper_4_2011/page67.html#/96

[2] http://www.rouesartisanales.com/article-15505311.html

[3] http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=109139

[4] http://cyclecraft.wordpress.com/2013/05/23/tested-mavic-cc40-carbon-clincher-wheelset/

[5] http://www.bikerumor.com/2013/05/06/first-impressions-early-miles-on-the-mavic-cosmic-carbone-40-c/


Can anyone identify this freewheel type? When googling the types it seemed to most closely match a Atom/Regina but it has 25 24 teeth and is about 3.5cm across. It's from a 1980s Raleigh road bike. But the bike has had a lot of work done to it so this part might not be original.

Thanks for any help

Clarification - I count 24 slots for a 24 spline removal tool, and not 25 as you state.

Jumping off from there I suspect you may have a Normandy/Maillard freewheel which takes a Bicycle Research Tools CT-3 24 spline freewheel removal tool.

Link to tool: http://www.bicycletool.com/normandymaillardfreewheeltool.aspx

Here's a link to the Bikeforums thread that lead me to the above link to the biketools website: http://www.bikeforums.net/classic-vintage/604233-freewheel-removal-tool-older-simplex-design.html


3 flats in 650 miles (1030 km) on hybrid bike. Tire pressure wrong? I have a Giant hybrid (with 700x32c 65 PSI tires), stock tires, that I mainly ride on nice roads to and from work ~3.5 km/2.2 miles each way.  I weigh 230 lbs/104 kg up from 200 lbs when I bought the bike sadly two years ago.

I check my tire pressure before I start riding again (If it's been more than 2 weeks) or every week. And I've put about 640 miles on the tires, but in that time I've had 3 blowouts.

That seems like a lot.

After doing a bit of reading it feels like my tires might be under inflated (I have a decent floor pump I use and I try to keep it right at 65 PSI) for the weight load (270 lbs/122 kg including bike), but I can't tell.  I haven't measured displacement under load (I'll do that when I get a new inner tube) to see if it's above 15% or not, but I don't thing there's any tire or rim damage that would be poking the tube either.

How do I tell what's causing the frequent blow outs?  Low tire pressure or too close to the limit?  Or are my expectations wrong on how often they occur?

edit: Okay, I removed my back tire and inspected the tube and there's a small hole bigger than a pin prick around the size of a pin head. There also seems to be pitting/cracking on the inner tube (Forte 200x28-32C made in Taiwan 2012 37 03).

This appears to be the puncture.

Do I just have low quality inner tubes? I've just been having the bike shop I bought the bike at replace my tubes.

General guide for optimum tire pressure on a road/mountain bike

Similar question

Depending on your attentiveness while riding, the hazards in the area you ride in and a few other factors, that may be a reasonable amount of flats.  I know a few commuters in my area that expect roughly a flat a week in their roughly 100 mile weekly commute.  I've ridden with this particular pair of guys, however and found they have a tendency to shortcut through glass filled abandoned parking lots and the like, and they don't pick careful lines through that mess.

I will say this about flats, when you change a flat, you should always figure out why/how you got the flat.  If you don't, you'll just get the same flat again.  Pull the tube, keep it oriented, re-inflate it and figure out where the hole(s) are.  There are articles out there telling you where to look based on the placement of your tube holes and their configuration.  If you are getting repeated puncture flats from objects, you may consider switching to more puncture resistant tires.  Keep in mind more expensive does not mean more durable.  I've bought ultralight and expensive race tires before that didn't make it 13 miles around a loop before picking up 3 punctures from gravel that wasn't even that sharp.  I ended up switching to a much heavier but more puncture resistant tire that was 30% cheaper and hasn't had any punctures since.  I don't race, so that works fine for me.

If your awareness doesn't keep you out of glass patches and the like (or they are just unavoidable in your area, I am pointing at you Honolulu) and you get repeated puncture flats, you may also consider switching to a tubeless setup with juice in your tires to minimize the impact of these.


Are single chainring mountain bikes usual? I just bought my son a typical+ mountain bike in a typical Frech sports shop (a BTWIN 530 at Décathlon) and realized that it has only a single sprocket at the front, and 9 sprockets at the back:

I have never seen that before (not that I looked very much, but I am used to the 3 + ~7 combinations) and was wondering whether this is

usual
expected
unusual but why not
you have been scammed

I can, worst case, return the bike but Decathlon, while being a Mr and Mrs Everyone shop, is usually fine (I casually rode their bikes for years).
LATE EDIT: thank you for all the answers so far - in light of the excellent details I got there I should have probably noted that this is a bike for casual, usually on-road biking.
LAST EDIT: thank you for all the answers - this is really a great SE site. It was near to impossible to choose THE answer, sorry for the others where I could just +1 (the update on road usage was great, thank you)

A 1x drivetrain (single chainring) is pretty much the standard now in mountain biking - you will notice the rear cassette is much wider than the classic 3x7 setup you are used to.  The wide rear cassette gives a wide range of gears (although not always as wide as the old 3x7). Most also have also moved to more speeds(sprockets) in the rear (i.e., 11-12 speed), if the 1x9 has a large range (which it appears that it does), it will have larger steps between gears than a 3x7 drivetrain you are used to.
Other changes in modern mountain bike drive trains are:

rear derailleurs are usually clutched to better retain the chain and control chain slap
a front single chain rings using narrow/wide tooth configuration to again better retain the chain

Better chain retention and a single rear derailleur means that riders have to think less about gears. In the modern setup you do not have to think about chain management, as the chains generally remain in the selected gear. Contrast this against a 3x7, where you often had to remember to shift Big-big (big ring, big cassette) before downhills to improve chain retention. This leaves the rider to focus more on navigating the terrain.
In terms of the pictured bike, the drawbacks relative to a 3x7 are likely a reduced range between the hardest and easiest gear and larger jumps between gears.

Update  - on road usage
The OP updated the question to note that the bike is intended for casual on road use.  The 1x setup is really tune  for trail usage were speeds are slower. Relative to the reference drive train (a 3x7), out of the box it will be less functional for on road use due to it being under-geared for the road (i.e., on the road you may find there is not a "hard" enough gear).  This can be alleviated by swapping out the front chain ring for a larger chain ring (as well as road friendly tires).  The gearing is more "tunable" than  reference drive train, where there were little option in the market  to change the 3x chainrings to different sizes.


Should I wipe my suspension fork stanchions with a wet or dry cloth after rides? Just wondering if I should use a wet or dry cloth to wipe my fork stanchions after each ride.

A damp cloth is probably the best option, but a simple paper towel is more than adequate. You don’t need to thoroughly scrub the entire stanchion. Just wipe away the ring of muck around the seals and anything on the stanchions that may remain. Be gentle; you don’t want to prematurely wear out your stanchions by overly aggressive wiping.


Which knee / shin pads for XC mountain bike riding? I'm considering getting some knee / shin protection for mountain biking but I'm aware that it might restrict my leg movement and make my legs hot if I get the wrong ones for the job (mostly XC riding).

What kinds of protection is available for XC mountain biking with the potential of falling onto   rocky trails at relatively low speeds (but still enough to be injured).

As @Slovakov said, these kind of protections are never seen in XC, the main reason being that XC is a low risk activity. You usually go at slower paces and you never put yourself in situations where there is a likely chance you can loose control and have a high speed crash in a dangerous zone (as you do in downhill or freeride, for example).

Of course you can fall and hurt yourself, but you can fall and hurt yourself if you are trail running, you can twist an ankle if you are playing basketball, or hurt a tendon weightlifting. You have to understand physical activity isn't without a certain degree of risk.

The only reason why helmets are highly recommended is because, even in the unlikely event of having a crash, an impact in your skull can have huge consequences for yourself - much more than any other part of your body.

Also, if you are concerned with your safety, it is my belief training yourself and learning to ride a bike in a technical situation is a very valuable skill. Lower your saddle, move your ass right to the back, learn to control and feel your brakes, etc. Start with easy areas and progressively advance to places which are more rocky and have more inclination. Being comfortable around these situation plays a big part in your safety.

With that said, if you still want knee protection, the most lightweight I know of are POC VDP Air Knee and Elbow Pads, Dainese Trail Skins or Race Face Charge Leg Guards. Six Six One also makes pads with various densities. You will easily find all of these with a Google search.

Have fun and safe riding :)


Converting downstem shifters to barcons What considerations should be made for converting a downstem shifting system to barcons? Both the current system and the system that I would like are friction shifters.

The bike is a 1986 Peugeot Iseran 10-speed.

Thanks and be well.

According to the '86 Peugeot catalog you're dealing with stem shifters. You should have cable stops on the downtube. You will use those. Measure your handlebar inside diameter to ensure you can find barcons that will fit. If it's not standardized, get a new handlebar.


How to stop bike renters overextending seatposts? A friend and I have been operating a bike rental shop for about a year, and just recently we've started to notice more and more customers extending the seatpost well beyond the maximum line. So far we haven't had any frame issues, just bent seatposts, but we're trying to get ahead of the problem before it costs us too much.
We've discussed assessing fines for this, as we do stress ahead of time not to overextend the seatpost, but we would like to explore some preventative measures. Are there any devices or solutions out there that would prevent someone from extending a seatpost too far?

I assume they are extending the seat post that far because they need it for an appropriate saddle height.
So the solution is simple: Offer bikes with larger frame sizes or at the very least equip the bikes with long seatposts which can be extended far enough.
Any other solution would force your customers to ride with a too low saddle.
If you still want to make sure that they can’t be extended too far, just in case a giant with long legs comes along, there is a solution I can think of: If you have seatposts where you can see through the tube (common on cheap steel seatposts) you could try to attach a string (or steel cable) somewhere at the bottom bracket, thread it through the seat tube and seatpost and tie it to the saddle rails. Could lead to some noise though if the cable rattles inside the seat tube.


hydraulic disk brake too loose I was trying to separate the pads on my hydraulic brake because it was rubbing, but I think I went too far. How do I bring it back? did it mess up the pressure some how?

As Nathan Knutson pointed out in a comment, squeezing the lever should move the pistons and pads inward. Do this with the wheel and rotor installed to avoid popping the pistons out of their holes (that would be messy).

It seems likely that the pads will rub again unless you do something else to correct the problem.

Possible causes of pad-rubbing include:

The caliper is not aligned properly with respect to the rotor.
The rotor is bent.
The pistons are not able to fully retract after the brake is
applied. This can be caused by sticky pistons or worn-out piston seals.
There's too much fluid in the system. If the brakes worked well since the last bleed, this probably isn't the problem.


Good idea to commute with a road bike and keep it outside? So I finally want to upgrade from my 1980 Schwinn World Sport 10-speed with suicide shifters to something more modern.

I will be working in Texas this summer and want to commute to work, but I highly doubt that the office has a place indoors to keep my bike.

Is it bad to spend $800 to $1000 on a new road bike if it will be left outside 9-6 everyday? I will have a backpack so a tarp is possible.

Forget the tarp. Ultimately, the greatest danger to your bike is not the weather, it's thieves. As long as you invest in a good lock, practice good locking technique, and don't live in an area full of degenerates you should be fine.

My bike is worth more than $1000 and I ride it all over and lock it up outside frequently.

When you select your bike, don't get the flashiest, most decal laden option available. Get a low-key, plain looking bike. Especially good if it has stickers and dings in it. Ideally, your bike will be the worst looking bike on the rack, let other people's bikes be the targets for thieves.

Here is a picture of my primary bike, which I've used to commute and go to the bars and get groceries etc (though I don't have the rack in the picture). I have a fairly fancier appearing wheelset on this bike, yet I've left it locked up in fairly dodgy places, but I still have it.

See this question for additional information regarding bike security: Theft deterrents (in addition to locking up a bike)


First Cyclocross Race - Riding a Mountain Bike I'm participating in my first ever bike race this weekend. It's a cyclocross race, and I'm riding a full suspension mountain bike, because I started looking into races late this season and a fully is what I've got. Is there anything specific to know/look out for since I'm not riding a cyclocross bike? Thanks!

Many first time cross racers use a mountain bike. It makes perfect sense, don't go out and spend $1500+ before you even know whether cyclocross is your cup of tea. Most all races allow mountain bikes, the only type of equipment that's usually forbidden is a fixed gear.

A full suspension mountain bike will do just fine as an introductory race vehicle. Your primary setback is that it's heavier than a cross bike, so it will slow you down when carrying it up a steep incline, or carrying it over the barriers, etc. But, those beefy ( and heavy ) tires might carry you through the mud quite nicely, maybe even putting you at somewhat of an advantage in a muddy beginners race.

Just be friendly and courteous out on the course, cyclocross is about having fun.


What model Peugeot is this? Anyone know what model this bike is?

I am trying to replace the front wheel of my fg/ss converted vintage Peugeot road bike. I've measured the spacing at 98mm, but because I don't know the correct year, I'm not sure if that is the correct spacing. Sheldon Brown lists 96mm as a common front fork spacing for an older french bike. The rear wheel had been replaced with a Wheel Master LP18 700 track wheel with 120 spacing. Also, most internet wheel listings don't even list the spacing.

Will this wheel fit: https://www.ebay.com/itm/Wheel-Masters-Wheel-Front-700-622X14-Wei-Lp18-Black-Msw-36-Aly-Qr-Black-Dti2-0Sl-/184149905030?_trksid=p2349526.m4383.l4275.c1#viTabs_0

Yes the wheel should fit assuming you have a 'normal' road bike fork installed. I've built maybe a 200 bikes and never had the front wheel spacing be an issue (only axle diameter was an issue when trying to install solid 10mm axle wheels into quick release forks (the solid 10mm axle won't fit in them).

If the spacing does differ a tiny bit you should be able to get away with it by bending the fork legs outwards a bit whilst installing the wheel (keep in mind this might be approx 1mm difference, so it's elastic deformation aka non-permanent bending).

The 2mm difference between your measured spacing and Sheldon brown's suggested standard size shouldn't be an issue. If the wheel is a tiny bit too wide you bend out the fork 2mm (elastic deformation once again), if it's a tiny bit too narrow you can clamp it down using the quick release or nut (if using solid axle).

Even with carbon forks this amount of flexing (when installing the wheel), shouldn't be an issue.

Regarding what model/year bike this is. I wouldn't know but it shouldn't matter if your question is only about front wheel compatibility. Some older bikes use 27 inch wheels but assuming you have the original fork installed on the bike (since the rear wheel you currently have installed is 28" and appears to align just fine with the brake pads of your current calipers) any 28" front wheel should be compatible whilst keeping your original brakes. You might need to adjust your brake pads a bit (their height) after installing the new wheel.


Inner tube popped on back side of the valve - why? One hour after my first 20-minute ride with new inner tube it exploded with "ps-BAH!" sound. Also, as you can see on the photo, two bulges appeared near the hole. The tire (25mm) allows up to 8 bar (116 psi) , I inflated it to around 7.5 (108 psi). Do you think it's simply a production defect of the tube?

EDIT: it's not a long cut on the photo, it's a seam. See full res image

What that looks like to me is that you had the tube pinched (folded) up along side the value stem.  That would explain both the cut and the bulges.  That cut looks like a tear - a faulty tube would have more of a clean split.

When you mount tire make sure the valve is free (you can push it in).


Trials: knee and elbow hurting, am I doing it wrong? I just started learning trials stunts. I'm currently playing at a trackstand / wheelie / endo level, so basic stuff.

Yet, my knee and elbow on the lead foot side are hurting... I know quite a few people who have bad knee problems, and I'm a bit worried this may happen to me as well.

Did you experience the same pains when you started trials? What did you do to fight / avoid them, did it go better with practice and muscles, or am I just doing it wrong somehow?

edit, one month later

Just in case some people stumble upon this later, with the same questions in mind...

I've given myself some rest, about two weeks, to let my body recover. Now with more practice, I tend to do smoother moves, and manage to avoid hurting myself.

I also try not to overestimate my capabilities and stop before I'm too tired and something bad inevitably happens.

Always wear a helmet, there are enough videos online to know how it feels like not to wear one.

Wear gloves, they protect your all-important hands. Remember your hands are your first protection when you fall.

I eventually invested in knee protections: my right knee met the pedal a few times, and trust me it hurts badly now.

Stay reasonably safe and enjoy your stunts :-)

This should be really asked to you physicist, not bicycle related forum.

If you are new to this, this can be "normal", as your bones and ligaments are not used to constant shocks. Do not ignore the pain. Take more time off, if needed.

This is typical problem for runners without previous experience. You can not just start running half-martahons without knee pains which can later lead you to meniscus surgery. You need to start slow and use 10% rule (increase your distance/time per week by no more than 10%).


How to check your dynamo system? I just bought my first hub dynamo (Shutter Precision PL-8) with dynamo headlight (Busch + Müller Lumotec IQ2 Eyc N Plus). After installation I figured out that light is not working. How to determine what actually is not working?

When checking a Dynamo system, there are 3 basic items which need confirmation:

Power Supply: Is your dynamo producing power? Checking this requires a multimeter, preferably with alligator clips on the wiring, and to spin the hub. Or there are specific tools, as well.
Wiring continuity: Are all connections tight? Are there any breaks/shorts in the circuit? This can also be checked with a multimeter. It is best done by isolating each section of the circuit to check, and then verifying the connections between the sections.
Light Source: Last, check your light source. Change the bulb if possible. Use an alternative 6v power supply to check whether the light head is functional or if there is an issue elsewhere in the loop.

Busch & Muller make a rather expensive tool for troubleshooting a dynamo.


Deformed/uneven/bumpy wheel/tire/tube, how to diagnose or repair? My bike has a deformation in the rear wheel, almost surely not due to the rim.
At some point the tire has a "valley", causing it to bump instead of rolling smoothly. I'd like to understand if I have to replace the tire and/or the tube.
I checked the tube and it seems alright, I put it on recently and since then the wheel has become wobbly though. Both tire and tube are 700x35 mm, and they should be the right ones for the bike, since the tire is the original one.

Update: I've "played" with the tire, deflating and re-inflating several times trying to get it seated properly. Now instead of a "depression" there is a sort of sideways deformation.
Also in this case the rim looks straight but I can't get the tire to sit right. I tried to put it in place in any way I could think, what am I doing wrong?

I've found the problem
I didn't notice it before, but the tyre was worn out on the side, and the supporting structure was deforming. I solved the issue by buying a new tyre.

It's hard to tell from that video - a side view would have been more useful.

From what you say it seems the rim is actually round in both planes - it doesn't wobble side to side or up and down as it rotates, so it's not that (but I can't see the rim in the video so I don't know for sure).

If the problem is the tyre it will be either because the tyre is not seated properly, or it's defective/worn out. But that sort of dip is unusual for a worn out tyre - normally they bulge (then pop). If the tyre isn't seated properly you'll normally be able to see it when you look at the side of the tyre. Where the dip is the normal markings on the side of the tyre will dip in too, meaning the bead has been pulled in on the rim rather than being pushed out against the sidewall/braking surface. If you're lucky that will have happened because the tyre wasn't installed properly. This is probably only on one side of the wheel, so check both sides. If it's on both sides probably the tyre is the wrong size for the rim, or you may just be particularly unlucky and have a slightly oversize rim and a slightly undersize tyre.

To fix, mostly deflate the tube, then work round pushing the bead in on the rim as though you were about to remove the tyre. Then pump the tyre back up slowly until the bead pops back against the rim. When this happens stop pumping, and make sure the bead has popped back all the way round. if not, work the tyre with your fingers where it hasn't popped - just squeeze the tyre in with your fingers. The movement should be enough to seat the bead properly.

But if it's a size problem you will need to buy a new tyre. If the size should be right but isn't, try a different brand of tyre. Some manufacturers are known to make "tight" tyres (slightly undersize beads), others do the opposite. Be aware that it is sometimes possible to put a 700c tyre on a 27" wheel (700c = ISO 622, 27" = 630 or so. ISO is roughly diameter, so the difference in circumference is 25mm or about an inch). It's very, very difficult to do, and shouldn't be done at all. If you're unlucky, you have one of the weird size wheels that's almost a modern size. Sheldon Brown discusses wheel sizes here

If the problem is the tube it'll be slightly harder to detect. Tubes are not every strong compared to the tyre, but if you somehow tie a knot in the tube that will affect the shape of the tyre. The most common problems here are a twist, which basically turns the tube into one of those balloon animals; and getting folded back on itself. The fold usually happens when the bike is ridden with the tyre very under-inflated or flat. The whole tyre rotates slighting on the rim as you brake or pedal, but the value stops the tube rotating with it. Until it breaks off, anyway. So you get a stretched part of the tube, and the other side of the value all the slack collects and folds up. When you re-inflate the tyre there's wobble like in your video.

I describe that first because it's easy to check and fix. Deflate the tyre, pop it off, and if there's a big lump of folded up tube next to the valve, there's your problem. Often you can tell just by deflating the tyre than pressing down around the valve.


Fixing hub gasket squeal I have a relatively new Salsa Journeyman, which has now, after about 200km, developed a squeal in the front hub.
The squeal is relatively quiet on low speeds, but gets noticeably loud when riding faster.
The wheel is fitted with an unmarked Formula hub, which i believe is a DC-20 model based on its shape.
I did already check the brakes and it's definitly not caused by them.
It looks like the gasket part of the hub is rotating with the wheel and causing the squeal.

How do I fix this squealing?

At 200km you should be able to take the bike to where you bought it for a free tune-up to adjust brakes and derailleur indexing etc.

Ask to have the front hub looked at as it definitely should not be making noise and will be covered under the warrantee. The problem might be fixed by lubricating the area around the rubber gasket, but you want to make sure there is not a problem with the bearings.


Does anyone manufacture a seatless bicycle? I need to stay fit and cycling is a great non-impact exercise. I don't see the point in sitting when cycling, instead I rather standing as such as it creates a better form of exercise. Are there any bicycles that are designed without a seat specifically for this purpose?

Most trials bicycles are designed without a seat.  However, they are likely to be uncomfortable when ridden for long distances.

You may want to consider what what you mean by "stay fit".  Fitness must have goals to be obtainable.  Cycling is generally consider to be cardio exercise that improves aerobic fitness.  Standing while cycling is more of a strength training exercise that is less maintainable over time.  I don't know of any manufacturers that produce a bicycle meant to be stood on all the time and intended for distance.  It's not something people try to do often, so if their is one, it would be very small, selling to a niche market.


City bikes-- frame sizing for smaller cyclists I'm a 5'1" woman looking to purchase a classic bike for transport/leisure. Unfortunately here in the London and in neighbouring cities/countries, I can only find 17"+ frames available. Most sizing charts recommend 15" for me.

Perhaps I have more flexibility given that I'm not properly sizing for a road/mountain bike or anything. Would a 17" frame be ok? I don't want to strain my knees or risk back issues.

Total novice at this, but I also measured my inseam in two different ways. 28.5" maximum if I want 1 inch of room while standing over the seat. 23" if I use the book method and allow 5 inches of room while standing over the seat. Seems like a lot of 17" bikes online lower down to 26" inseam height.

Many thanks!

I helped a friend having a similar issue long time ago (she was 154cm ... I think it is similar height to yours, right?).

What we found was that a 17" frame would be okayish regarding leg's length, but a bit of a stretch regarding the torso/back, because the handlebar was too much forward.
However, for cycling stretches of 20-30 minutes this may be ok and you may still have a relatively simple albeit unconventional solution: reverting the stem (the metal piece used to attach the handlebar to the fork) to point backwards

In our case, the solution was to buy a 26" bicycle.
Sometimes these bicycles are advertised as "young adults bike" but they are completely adequate for your declared purposes.


Are there any folding adult tricycles on the market in the UK? It is easy to find folding bike, but where do you get a folding tricycles?

There is the Azub Eco [recumbent tadpole] Trike. However, if you watch the video of the folding, it's no Brompton.


How can I maximize the lifetime of my cleats I'm using look kéo cleats. My right one is much more worn down than the left one. Almost to the point where I don't think it will have any edge showing on the front lip.

I do walk in them a bit, but usually in grass or on smooth tile. In both conditions I would think it's the heel hitting the floor more, so the front wearing quicker is a surprise to me.

What are some causes of early wearing on cleats and how can I prevent them?

You can get special covers for your cleats that make it easier to walk and extend their useful life.

http://www.amazon.com/gp/aw/d/B000UDBLQO


mountain biking - post ride tasks After completing a long mountain biking trail (complete with lots mud and water etc) - what post ride checks / tasks should I be doing?

I ask this because I don't want to be taking my bike into a shop to be fixed just because I've not been maintaining it properly after a ride.

Thanks.

Clean everything up and lubricate your chain. Wash the suspension and make sure the seals are fine. If you have a rear suspension pay attention to the pivots. For the rest it will pretty much be covered in a pre-ride check.

Check out the questions tagged cleaning here on Bicycles SE to read some interesting information on how to clean different parts of the bike.


Understanding science of speed difference between two bikes I have two MTBs and one is slower than the other.

Bike1 has Deore derailleurs and a double chainring with 10 sprockets and Shimano hubs. Which has a great speed irrespective of the gear combination.

Bike2 has Acera derailleurs with a triple chainring and 8 sprockets with acera and Quando hubs.

The second bike is much slower than the first one in terms of speed.

My question is, apart from physical strength, which is more important for speed, a hub or drivetrain?

I want to upgrade my bike. Can anyone guide me to get more-or-less the same speed. Both bikes are from same brand and almost identical in terms of dimensions and shape.

Please help me to understand the science.

There is a myriad of factors that can effect how 'fast' a bike is. By 'fast' I mean both maximum speed and acceleration. When riders talk about a bike being 'fast' they usually means it accelerates well. You don't state it explicitly but because you have Deore and Acera drivetrains I guess you have mountain bikes. Acceleration and climbing ability is much more important on an MTB than straight line speed.

Acceleration is force/mass. More force, less mass means more acceleration. The Acera bike although similar to the Deore bike probably has downgraded components, frame and wheels and weighs more. If you think about it an Deore  level bike from the same manufacturer should be designed to be faster than a Acera bike - that's why the Deore bike can cost more.

Anything that soaks up energy will reduce the amount of force applied to the pedals that makes it to the contact patch between the rear tire and the ground:

Drivetrain losses - friction in the chain, wheel bearings, bottom bracket bearings. Chain friction is dependent on wear, how clean and lubed it as and also the angle it has to run at.
Rolling resistance of the tires and wheels. This caused by the tire deforming and is heavily dependent on tire size, pressure and construction.
Suspension losses - if pedaling causes the suspension to bob up and down energy is lost. That's why forks and rear shocks have lockouts
Anything else that flexes - frame, wheels, crank.


Easiest way to remove a chain master link / masterlink When I'm breaking a chain with a master link (to remove the chain from the bike), usually I can do it with my hands by pushing the links together until the master link comes apart. But sometimes it's trickier than others, and can be a recipe for sore thumbs.

I know there are special tools that help with this, but I'm curious if there's a trick I'm missing.

What is an easy, reliable way to un-do the master link (even when stuck), without any specialty master-link-specific tools?

You have to remove the tension from the chain. One way is using a small piece of wire to slacken the chain such as this one made by Topeak:

which you hook in a few links to the left of the quick link and a few links to the right.

Another way is to use the rear derailleur. Then, just pinch them together and slide your fingers opposite ways.

If that still is too hard, you can use a tool like the Park Tool MLP-1.2 or a pair of needlenose pliers as a substitute.


Whats the easiest way to clean my bike? Simple question, however, I am used to cleaning my bike at my parents house, I use some eco bike spray stuff leave it for a little then rub and hose down (I normally get it quite dirty riding down dirt tracks in West Sussex, UK).

I am now at University and our flat has no access to a garden or hose pipe, the best place / possible way I can think to clean it is out on the pavement next to a busy road with a tub of water and a sponge.

Would anyone recommend taking their bike to a garage and jet washing it down? Anyone found a really easy way to clean their bike with limited space?

Don't forget to TF2, thanks.

In the winter when the garden hose is disconnected I use a watering can filled with warm water to wash the dirt/salt off the bike before taking it in. I use mild detergent soap to speed up the removal of oil and grease then pour the warm water from the can to remove the soap.


Carbon frame damage from chain Sustained some damage from a chain coming off, and it's done some rather nasty damage to the paint, frame itself looks OK?
Other bikes I own have a metal plate here to protect the frame, is this not standard?
Feels and sounds solid, is it still OK to ride?
Will Specialized repair this under warranty?

From what can be seen in the picture it looks like the damage to paint only. The top layer has been chipped cleanly off, and there are no carbon fibers exposed from the epoxy visible.

That said, I'd have a bike shop look at it in person.

As far as I know, no manufacturer will replace or repair a frame that has sustained damage from the chain or a crash.


Minimum insert for stem: line or arrow I would like to raise my handlebar and have come across the following markings on my stem.
Can I raise this stem only until the upper arrow disappears or does "Min Insert" refer to the line below and I can raise it 2-3cm more?

Thanks for your help.


Minimal Low-Rider Touring Front Rack Recommendations We're in need of a good, reliable low-rider front rack for long distance touring. I've come across a good number of heavy-duty front racks with low rider rails like this from blackburn

(source: blackburndesign.com)

But they get pretty pricey, and seem to include a lot of bulk we don't need just to hang some panniers. The best option I've seen to date is this front rack I spotted that comes with the new REI adv 1.1

but after a few inquiries it sounds like there isn't any way to get the rack on its own. There are also options like the Salsa Down under or Blackburn cl1 which looked promising, except they require midfork eyelets on the outside and inside, of which we only have outside midfork eyelets.

The axiom journey rack also looked promising and at a good price

but it doesn't seem intended for use with frame eyelets, and moreover, it doesn't look like it can be mounted level with the ground (I've heard this is important, but correct me if I'm wrong).

I figure there is a solid chance I'm just searching for something that doesn't exist, but it would be awesome to find a minimal, inexpensive front rack. I've also seen things like this Tubus

which look good but come at a steep price. Maybe that's just the price you have to pay, but I'm hopeful there might be some alternative.

I've got the Blackburn CL1 you picture or one almost identical.  I bought it for my hybrid and only ever used one side (D lock the other side) and I only got it to fit by cutting off the bar to the inner screw hole.  Now I've put it on a tourer that does have the right screw insert, but none of my panniers fit with that inner bar, so I've cut it off on that one too.  This of course weakens it in the lateral direction, but that's something I accept given that I intend to load it lightly and only use it occasionally.

Getting the P clips on the diagonal bar to align and grip properly has also been a challenge (not helped by disc brakes and full mudguards).  The bar for the lower pannier clip (anti-sway) isn't very versatile, but I want to put my Altura Morph backpack pannier on there, which is really meant to go on the back.

Overall I only recommend this design if you're prepared to accept a lot of fiddling and modification, but it is light.  If/when I get something new I may well go for one like your top picture for serious heavy duty, or that Tubus at the bottom.


Where should the brake calipers grasp the rotor? The brake calipers on my front disc brakes appear to be grasping a bit further in than I would expect.

You can see that the calipers do not grasp the outer ~15% of the rotor. I imagine that if they grasped the whole outside section, braking would be slightly stronger. Also, braking currently shudders ever so slightly (although this rotor is much better than the previous one). By not grasping so much of the inside supports, this shuddering might be reduced?

I went into my LBS, but they were a bit vague. They said they didn't "know the tolerance of SRAM rotors", although the previous rotor had the same issue. They also claimed that the fork was manufactured correctly, although "if I wanted to" they could fix the position, probably by spacing the HY-RD out by putting some M16 washers in. They didn't really say whether it was of concern or not.

Are the calipers grasping at the correct position?
If not, what is to blame?
Is putting washers in a safe fix?

It is a 160 mm SRAM Centerline X2 rotor with a TRP HY-RD caliper (on a Soma Double Cross fork).

Also the calipers are at the limit in the z-plane, i.e. they are pushed out away from the wheel as far as the mount will allow, so there's conceivably another issue there.

Update

I changed the Shimano adapter for a TRP-branded adapter. I'm not certain if it solves the problem of the grasping at this stage. I'll leave it a few days and see if it clears the outer dirt ring on the disc. However, the (related?) problem with the lateral position of the calipers is worse. With this new mount, they are pushed out as far as possible, but the outer pad still rubs against the disc.

Update 2

Changing brands of adapters had little effect. In fact, the TRP-branded ones were probably slightly worse than the Shimano.

I took my bike to a fourth shop to try and sort out the shuddering. They decided to put washers in, moving the calipers out. However, they used the washers that have some lateral movement (I think the same as Mike Baranczak's answer). This may have slightly fixed the z-plane issues mentioned above. The shuddering is much better, but now the brakes screech terribly, and the stopping strength is still less than expected.

I will see them in a few weeks to see if they can tweak it more. I will update this question further when I have more definitive results.

Some amount of unworn upper lip on the rotor is normal. For example, when you try to measure a round-edged rotor with a caliper, usually it doesn't work from the outside edge because there's some kind of lip there. The entire brake pad surface should be contacting rotor - in other words, there shouldn't normally be any lip getting worn into the pad. If there were, that would be your real sign that the pad isn't making full contact. But because it can't be totally perfect, it follows that the rotor is wear the unworn spot is going to show up. This one does look a little more extreme than normal, but I think it's fine.
The first thing I would do if I suspected a problem is check firsthand that the mount is actually to spec, since it's pretty simple. Use a caliper or even a pocket rule and poke a skewer through the axle without the QR nut to give you an easy spot to measure the center of the axle. Here are the dimensions. If it's not that then it may be a peculiarity of how this rotor is getting along with this brake and adapter. In my experience, even though it's not supposed to matter, you can save yourself some grief by mismatching adapter/caliper/rotor as little as possible, and you've got a different brand for each here. I do tend to be willing to put in Shimano rotors on anything. (Just to be clear, mismatches shouldn't matter and usually don't.) I think part of what may actually be going on here is the pad type used by the HYRD is just a little taller than most or all of the SRAM/Avid pads and it's making it look like the rotor wear is going further than normal into the large cut-out section of the rotor.
Up to 2-3mm or so should be fine if you want to try this. I would feel like I was doing something wrong if I stacked them up any more than that in a shop setting. I don't really think it's worth messing with upon further consideration.

Edit: Substantively changed this answer after thinking it through a bit more.


Nine speed derailleur on 10 speed cassette Will combination work? I have 10 speed shifters, 10 speed chain, 10 speed cassette and all components are Shimano.

The reason I ask is because I am new to cycling and I am having trouble indexing my gears. Gears skip and I get some catching. It just might be not indexing properly or it might be the combination.

From a comment:

  It’s a road bike but decided to go flat bar initially from a comfort aspect, hence the reason for the Tiagra flatbar shifters - 10 speed. All components are new, frame is second hand, hanger is straight from what I can tell. Cassette is 10 speed Ultegra, derailleur 105 9 speed, chain is a 10 speed SRAM. It’s a mix and I would have gone all 105 10 speed but I bought it aftermarket from a bike shop, and I am only making sense of the components now.

EDIT: Take delivery of the Tiagra RD 4700 tomorrow.Will let everyone know how it goes.

Assuming you have Shimano components, it depends if you have an MTB or road groupset.

Shimano used the same actuation ratio (ratio of cable length pulled to lateral movement of derailleur cage) for road 8, 9 and 10 speed systems then changed for 11 speed. Theoretically a 9 speed derailleur will work with a 10 speed shifter and cassette.

On the MTB side the change to a different actuation ratio was made at 10 speed, so a 9 speed MTB derailleur will not work with a 10 speed shifter and cassette.

A well known exception is road Tiagra 10 speed 4700 series which uses a road 11 speed actuation ratio (although I'm not sure that it's exactly the same, a Tiagra 4700 10 speed derailleur may not work with a 105 5800 or Ultegra 6800 group.)

Indexing is not too hard to get right (if you have matching shifters and derailleurs of course). Park Tool has a good page that explains how it works.

If you cannot get the indexing right at both ends of the cassette you may have another problem. A bent derailleur hanger is a common culprit. Cables hanging up in the housings is another.

If the chain is skipping over sprocket teeth rather than ghost shifting you likely have worn sprockets.


10/11 speed freehub compatibility I have a Sram 10 speed cassette and I'm looking to upgrade to Shimano XT M8000 1x11. I wanted to know if I can use the same freehub body or if I need to get a new one.

Thank you for your help.

Yes, it will work fine. For road cassettes, the freehub body length had to be increased for 11 to fit more cogs, but for mountain there was no such change because the largest cog slightly overhangs the hub flange.


How can I avoid mud from splashing onto my back without a rear wheel fender? I enjoy cycling off-road. During rainy season, the cycling trails can get muddy. Most of the bikes from rental shops do not come with a rear mudguard. I tried to slow down and avoid puddles of water, but it seems inevitable that blotches of mud would stain the back of my shirt at the end of the day.

Are there better methods of avoiding mud from splashing onto my back?

Use a seatpost-mounted rear mudguard, like the SKS X-tra Dry:

For the front, you can also use a downtube mudguard like the SKS X-board:

These are convenient for bikes which don't have proper fender mounts/fenders would interfere with clearance/fenders need to be easily removed or not [Most mountain bikes fit this thing]. They don't protect the drivetrain from crud thrown up from the wheels so they aren't great for improving drivetrain life on a road bike, but this is not a concern for your riding.

The other option is to wear clothes you don't mind getting dirty.


Derailleur replacement recommendation I have been experiencing some issues with my rear derailleur. I played around with it quite a bit to adjust it correctly. Finally after giving up, I took it to the shop and the guy showed me that the rear derailleur is bent, plus the chain is stretched. So, I am considering changing it along with the chain.

I need some recommendations, not necessarily on the exact model, but the type of derailleurs. The person at the shop recommended Shimano Deore. But I noticed that these seem to be for mountain bikes. My bike is more of a hybrid (if that is what it is called) La pierre Shaper 100.

Would regular road bike derailleur's work? I use the bike mainly for commute (36kms/20miles daily).

Would really welcome suggestions, thoughts, etc?

Thanks

Edit. Down the line I might consider changing the rear cassette from 8 to 9, or maybe 10, will the front derailleur have to match up with the new cassette at the back and the new rear derailleur to make sure each gear in the front has a big enough range for gears at the back without the chain touching the front derailleur?

According to your link - your bike is 8 speed.
The bog standard (excludes the upper-end XT variant) Deore derailleur has only ever been produced in 9/10 speed.
And one assumes - you are looking at the latest 10 speed version.
An 8 speed chain is significantly wider than a 10 speed chain. Consequently, the chain may have problems with not only the jockey wheels of a 10 speed derailleur but also passing through the cage of the mechanism.
Additionally, MTB rear mechs - can run much wider range of gears and therefore can have a longer cage to facilitate this. With the range of gears on the link - you would require a medium cage rear mech.

You bike runs the Shimano 2300 range. And I would recommend sticking to this or something like the Shimano Claris range. These are also road specific & probably cheaper than a Deore rear mech.


Performing on long and tiring tour I am not talking about the tools needed for the ride. I am talking about enduring and performing on long tiring tour. Grab a concept of a tour I recently went to

  25 Km Uphill > 40 Km Downhill > 30 Km Up hill > 10 Km Downhill > 26 Km Uphill

Then I came back

  26 Km Downhill > 10 Km Uphill > 30 Km Downhill > 40 Km Uphill (exhausted)

On about 15 km on the Uphill, I couldn't do it any more, took a bus, and came home.

I eventually was overdoing on the downhill and on some sprints.

I am not sure how to put up this question, but How to cycle, when heading for a ride I mentioned above?

More details:

  I am a regular commuter but, the ride above was a personal challenge
  to myself and the first time doing this. Before this my longest ride
  was 82 Kms in a single day.

  There were frequent stops on the up-hills but none on the down-hills.
  I hydrated frequently but as food, I had packed some energy bars and
  nothing more. I sprinted to maintain the speed not to go fast which was definitely overdoing.
  Average speed on the speedometer was 18.xx (forgot) Km when I decided to stop and I cycled
  for about 11 hrs. For rests, I was relying on down-hills mostly. Slopes were not very steep but were tiring due to length of them.

  I was riding on big MTB tires.. which gave a lot of trouble with the
  speed (as expected).

Basically, it's 2 things; training and nutrition. My guess is that you either didn't get in enough quality training and/or you were not properly nourished on the ride.

For Training

One of the best ways to build up to longer rides and ride them enjoyably is through interval training.

The best book I've found on the subject is: The Time-Crunched Cyclist: Fit, Fast, and Powerful in 6 Hours a Week by Chris Carmichael. The book includes a lot of info on lactate threshold, energy metabolism, nutrition, race and century training plans, etc. I first tried out his methods after reading one of his articles in Bicycling magazine on century training. Another great source for long distance training plans and ride nutrition is Joe Friel's blog for endurance athletes.

Basically, Carmichael's methods are a form of interval training where you are doing things like hill-repeats, power intervals, fast pace intervals, etc. There's a lot of info out there on interval training. One of the more common is called HIIT (High Intensity Interval Training). When I train for a Century+ ride, I'm basically doing training rides 4 - 5 days a week with most of them being maybe 2 hour interval training sessions with longer (4 - 6 hour) rides on the weekends. Coming out of the off-season it typically takes 8 - 10 weeks to train for a century type ride, provided that you are already fit; easily longer if you've not done this before.

All that being said about training, if you were really intensively training before the event; it's conceivable that you over trained and your body was just too spent to make the full effort. It's important to remember that rest days are vital in training for challenging rides.

For Nutrition

Once you've trained well for a long endurance ride, the next key for success is nutrition on the ride. Essentially, you want to consume carbohydrates during the entire ride. Carbohydrates are fuel and without fuel, you WILL bonk.

So, on a supported ride, I make the stops and eat carbs with small amounts of some proteins and fats, plus carry along energy bars. For un-supported rides, I've had very good results using Perpetuem which is a product made by Hammer Nutrition and there are other similar products on the market. This product is primarily maltodextrin plus protein powder plus a bit of fat and some vitamins. (Without getting too in depth, maltodextrin is a polysaccharide consisting of long chains of glucose which is readily used by the body). The beauty of this product is that it's a powder and a large number of calories can be carried in a cycling jersey for mixing into water bottles. Also, on un-supported rides, one can always bring food along and stop at stores along the way.

Another vital component of endurance riding nutrition is to be sure to stay hydrated and make sure that you consume electrolytes.

A typical long ride (Century (100mi/161km) to Century+) nutrition plan that I use along with my  riding buddies looks something like this:

Supported leisurely century - We just stop at the rest stops and eat whatever we feel like.
Supported challenging century - Again, we enjoy the rest stop foods, plus carry along some extra energy bars/other and normally some maltodextrin formula for extra efforts (climbing, headwinds, etc)
Unsupported leisurely century - We bring along various energy foods/bars/endurance sport formulation and typically have lunch at some cafe or whatever along the way.
Unsupported challenging (remote, mountainous, often altitude) century - We rely heavily on endurance sport nutritional formulations, plus bring along a few bars/etc to break up the monotony.

The main point being to consume easily assimilable food (carb/starchy) all along the way. Generally avoiding high fat and high protein foods, as digesting fat/protein 90 miles into a 120 mile ride is usually detrimental to performance and getting over that last mountain pass.

My answer is based on lots of long distance cycling in the Coast Ranges and Cascade mountains of the Pacific NW and California and learning by trial and bonking...although it's been quite a while since I last bonked... Also, I have been know to extol the virtues of The Time Crunched Cyclist and that's because the training methods in that book completely transformed my long distance cycling abilities.

BTW - This year I have been working on some DIY formulas for ride energy nutrition. It looks like a roughly 4:1 ratio of maltodextrin:protein powder should work. The raw ingredients are much less expensive than pre-packaged versions.


Moving tfrom Shimano 9- to Shimano 10- speed I'm thinking of changing the 9-speed Tiagra rear mech on one of my (road) bikes to something, still Shimano, but 10-speed.

The obvious replacements I'll need are cassette, right-shifter and chain. But I reckon because of the narrower chain I'm also looking at a new chainset and rear derailleur. However I think the front derailleur and left-shifter should be safe (still keeping the front mech the same). Ditto the bb, regardless of whether I need a new chainset

Has anyone actually done this conversion and is able to confirm (or put me right)?
Thanks

Update

Decided in the end that going from 9- to 10- was too much to spend all in one go. But I used a service as an excuse to change the cassette (to a 9-speed ultegra) and the chain (dura ace) at quite minimal cost. Can upgrade other parts as and when, although I'm basically looking at Shim's 6500 range here so all quite dated now.

You will need a 10-speed cassette, 10-speed rear derailleur, and 10-speed right side shifter and a 10-speed chain to work with the narrower spacing on the rear cassette. There tend to be some compatibility issues with 9-speed derailleurs run on a 10-speed drivetrain (some people seem to have luck using 9-speed shimano mountain derailleurs with 10-speed shifters, but YMMV).

Your 9-speed front chainrings should be fine.  Sheldon seems to agree on that point However, I wouldn't expect it to work on 8 or 7 speed chainrings, but it very well may.  I've upgraded my own 10-speed outer front chainring with a 9-speed one on a 10-speed Tiagra setup and haven't had any issues with it. There shouldn't be any issue with the left shifter, derailleur, or bottom bracket, those should be fine as well.

One other thing to consider is the brakes. 10-speed STI shifters may have a different lever pull ratio than the 9-speed levers, this may only apply to ultegra and dura ace though (please correct me If I'm wrong on this). So, you'll probably be OK if you're sticking with tiagra.  Otherwise, you may want to upgrade STI levers at the same time and possibly get brakes with a matching pull ratio.


Can I replace 700×23C tire with 700×28? I have Trek 1.1 with currently 700*23C tyres.

I need to replace them but the one available in market are 700*28

Can I use this size as replacement?

If yes, what'll be advantage and disadvantages?

Your rims can almost certainly take the extra width.  The real question is can your frame, forks, and brakes?  Only you can measure that.

Based on nominal dimensions (and some approximations) you would need an extra:

2.5mm either side to the chainstays/seatstays and forks/brake arches.
5mm above (to clear the brakes) and in front of the back tyre.

A few bikes even have the front wheel very close to the downtube.  This assumes a very similar tyre to the one you have, just a bit bigger. You need to add a bit for safety margin, plus you need some clear air between the new tyre and the frame.  So do you have enough clearance around the tyre?

The 28 should give a slightly more comfortable ride, and may even be more efficient.  You'll need a slightly lower pressure.


Using trainer as dynamo I was wondering if it is possible to to use a magnetic trainer as a dynamo.

While riding on trainers, at a gym, or at home, I always think to myself, "I wish I could capture all this energy and put it to good use".

Has anyone ever turned a trainer into a dynamo?  If so, I'd like to know what modifications are needed and what tools and parts are necessary, plans, etc.

Moreover, I'd like to know if it is then possible to use this dynamo to supplement power to ones' home, as opposed to just storing it.  While discussing it with a friend, the main challenge that came to mind was converting the current to A/C and synchronizing the phase, voltage, frequency, etc. with the power coming into the house.  Probably a bit overkill if you're not an experienced electrician (which I'm not) but maybe I'm wrong.

If hooking one up to the home is not realistic, is there any simple configuration that one could use to provide useful energy and store it?

You could. If you were a hobbyist, it'd be simple enough to hook a DC motor to act as a generator, smooth the output, boost-buck it to the right voltage, and use it to charge a deep-discharge lead-acid battery.

From there, you could either use it to charge your USB equipment or get an inverter to run some lights. I would not hook it into your mains, the equipment to do so safely is expensive.

I'd estimate the setup would cost just around $200-1000 depending on what parts you already have lying around.

===

That said, let's say you already had most of the parts so it only cost you $200.

You could most probably output 100-400 watts an hour. Let's say, you're in very, very, very good health and can do 250 watts for 2 hours a day. That's 500 watt-hours. Over a month, training 20 days that'd be 10,000 watt-hours or 10 kWh.

In my region, electricity is 20 cents a kWh, so you would be generating $2 a month.

So you would amortize your equipment cost of $200 over 100 months or 8 years. That's if you're in excellent health.

Note 0: Values chosen for ease of calculation rather than strict adherence to reality. However, I believe they are within an order of magnitude correct.

Note 1:  your energy expenditure will be such that your increased food consumption will likely exceed $2/mo.

Note 2: if you break or wear out anything, you'd be back to square zero. Even deep discharge batteries have a limited life span.

Note 3: This model doesn't include charge/discharge/inverter inefficiencies. You should most probably multiply everything by 70-80%.

Note 4: this exact scenario was used in an episode of Black Mirror, season 1.


Thule jogging kit twisted? I recently bought a Thule CX2 Chariot with jogging kit. The front wheel tracks to the right.
The jogging kit consists of two aluminium arms, a wheel and a quick release skewer.
When I look at the arms, installed side by side, one side is higher the other.
Any thoughts on how to balance them out?

One arm has an adjusting knob that forwards/retracts it, therefore correcting the trajectory deviation. See the blue Knob and the black plastic that it moves on the picture bellow.

No need to overadjust it, since small changes in how the wheel and/or arms are inserted will change the trajectory center the next time. Just make it good enough and correct small deviations by pushing the cart unevenly.


Tune mechanical disk brakes TRP Spyre C On my bike I have SRAM Rival levers paired to TRP Spyre C mechanical disc brake calipers. I'd like to tune them to "brake harder"; currently, I have to press more than half of the way on order to start braking. I can't find any way to do that. I could change that directly on the cable on the brake, but there ought to be a better way.

I could change that directly on the cable on the brake

I think by that you mean undoing the cable attachment bolt, pulling the cable tight and re-attaching it. You are correct, that's not the way to adjust mechanical disc brakes, unless you have lots of cable slack that needs to be taken out.

Different models of mechanical disc brakes have different adjustment controls, so you should look up the manual for what you have on your bike. The Kona Rove ST has TRP Spyre C calipers, the manual for which is here.

The manual says there is a barrel adjuster on the caliper and a pad adjuster. (I think this moves just the outer pad so you would need to re-align the caliper if you use this adjuster, but you probably need to do that anyway).


How do i determine Bianchi Infinito year of manufacture from these labels WBK446115F and TPJ611528F? How do i determine Bianchi Infinito year of manufacture from these labels WBK446115F  and TPJ611528F?
These labels are on the frame bottom bracket.

Phone the bianchi distributor and ask them. The UK one is very helpful.
web search Bianchi Distributor (country x)
I'll add that it's normally quite easy to tell the model year by the livery. With Bianchi you can also tell the original specification by the livery. Compare yours to the back catalogue.


Why are master links so expensive? 2.51 euro for a quick-link (the cheapest)? But this is not so different from just single chain link. Why such prices and not for a dime?

There are two ways to price a product - Cost Plus or Value Add. To survive, Cost+ must be less than VA or you can only sell your product for less than it costs to make. If C+ is less than VA, you an sell at any price point between them. Too close to VA, you encourage competition, to close to C+, you forgo profit. Something like a master link, I can't imagine someone thinking "I know, I make master links, sell the 10% cheaper and get rich" - the market is too small, and too brand loyal....... So the only competition to master links is not using one......

If you don't use a Master link, you need a special tool (chain breaker), and skills to use it. The tool is about 10x the price of a master link - so you could buy the tool and not have to buy a master link, or you could just buy the master link - 10 times if needed. Most of us buy a hand full of master links and just use them as needed till gone, the $25 price tag is forgotten a long before the next $25 top up is needed, but if we run out, that $25 is well remembered reassembling a chain with a tool - as money very well spent......

I own a tool, and would not be without it, but always use a master link.........


What Size Screw Holds the Up and Down Shifting Levers on Ultegra Shifter? There's a screw on the back of my Ultegra (circa 2000) shifters that holds the down shifting (on the right side) inner lever, to the up shifting outer/longer lever. I've long struggled with it loosening, but last week it fell out during a bumpy ride.

I'm having trouble describing it, let alone finding a replacement screw. What size is that screw and what should I call it?

Surest way: Measure the screw on the other shifter and get a replacement at any place which sells screws. Use screw glue if you already know the screw comes loose easily.


How long should pedals last? I use cheap flat pedals, aluminum or plastic. They lasts about a year (1K-2K kms) before dying (cracking noises at each stroke).

I don't mind paying US$10 each year, but it hurts my eco-heart: I want to recicle, to repair and not pollute the Earth.

How long should pedals last? Do serviceable pedals last longer? May I try to repair non-serviceable ones?

Increase your budget until you can afford second hand pedals with cup-and-cone bearings, then spend a few bucks servicing them.

DMR's V8 and V12 models are very popular and have been the same for years. The V12 typically has better seals and lighter materials than the V8, but both are serviceable.

Here's a guide on servicing the DMR V8:
http://steveukmtb.wordpress.com/dmr-v8-pedal-overhaul-cup-and-cone/

I got Wellgo's V8 clones via eBay for 7GBP delivered (about 10USD?). I don't know if they're the same internally but they might be an option if you cant get pre-loved DMRs.


Pedal extensions for one-legged bikers I have tried the classical plastic pedal extensions as in the picture. I have tried riding with one foot, but it was a little bit hard pulling up. I was wondering if anyone knows of an extension for a one-off legged person riding a bike. I thought the following would work:

Any ideas?

Also, there would have to be a mechanism for ensuring the biker did not have a bad fall in case the bike became unbalanced and the biker fell on the side the biker had no leg. How would you prevent this? Would you just attach small-child-like accessory wheels on only one side as follows?

Maybe the back supporting wheels might be enough, otherwise the biker could not turn the front wheel.

Maybe some sort of mechanical spring plus other components would be needed attached to the front supporting wheel, sort of as follows, although the picture is not a good one:

How would you do it?

Does something like that exist?

Thanks.

There are many ways to approach this problem.  The WORST thing you can do is not involve the rider in the decision making process.

If the rider is comfortable riding, perhaps all you need is a regular bike with a toe clip (as pictured) or a clipless MTB shoe with a cleat underneat, and a matching pedal.   SPD would be the most commonly known style.

There's no need to remove the other-side crank although that is a good theft deterrent.  In fact it may help to add a little weight to the empty pedal.

A little wheel on the off side is likely to hook on things or cause more problems than it solves.

More spendy options exist too -

Tricycle  Solving the balance problem by adding a big third wheel instead of little kids one.

Handcycle  These are powered totally by the rider's arms, not by the feet (foot)  This one is probably a tricycle, but the theory works the same for a 2 wheeled bike.

Here's a handcycle built onto a wheelchair - its possible to remove the front part and return it to normal wheelchair mode.

Prosthetic Depending on how much of the leg is missing, its possible to have a strapon leg that rides like normal.  Above-knee amputee's comments or this guy who rode the Haute Route with one leg and one arm


Is a Surly front rack compatible with tubus mount for eyeless forks? I am looking at the Surly front rack and was wondering if it's compatible with this Tubus mount.

If it's not I'll have to go for the Tara but I was keen on having a platform on my front rack. Any decent recommendations ?

The rack and Tubus mounts will work together. You should double check that the Tubus mounts fit your particular fork. If you are looking for a porteur style rack (with the front platform), also consider the Specialized Pizza Rack, the Soma Fabrications Porteur Rack and the Velo Orange Porteur Rack. The Velo Orange rack doesn't even require fork eyelets.


Is anyone really convinced of ANT + technology/benefits? I want to replace a computer with a new one (triple wireless) cadence, HR and speed but am in two minds as to if I should get a comp with ANT+. They seem more expensive and for what I will use it for, I don't need the connection to an app/computer.
Comments?

Definitely go for ANT+. If a sensor packs up, it's much easier to replace it if it uses ANT+ rather than a proprietary protocol. If you want to upgrade anytime soon (to get GPS etc) you only have to replace the head unit. If decide you want to track your rides on Strava/ridewithGPS etc you can connect to many new phones (mainly Samsung and Sony). Well worth it.

You can get something like the Cateye Stealth 50 for not much more than any other wireless computer.


smaller wheels on big bike to reduce height I have a SEKAI sprint 1000 bike which is a tiny bit big for me as I have problems reaching with my feet to the ground. The existing seat is already down to the lowest level so can't reduce the height any further.
What I am thinking is to change the wheel to a smaller size. The current size is 27 1/4" (rim). Can I install smaller wheel on this bike without having replace virtually everything?

If there is a seat available which has slightly lower seat frame so that if I replace the seat then it goes a bit lower (hope this makes sense?)

The first problem with changing the wheel size is surely the brakes. Assuming they're rim brakes, they won't be in the right place for a smaller wheel.

In any case, is it the distance to the ground that is an issue or the distance to the pedals? If it's the latter, then changing the wheel size won't help, however, you might get an extra 5 or 10 mm by using shorter cranks - if this is appropriate for your height.

I would imagine that it's probably better and not much more expensive to trade the whole bike in for one which fits you.


Why is my front crank clicking/creaking? I've purchased a new bike. Carrera Hellcat is the model.

I'm getting a click noise from the front crank but only when the middle sprocket has the chain on it, there are 3 at the front. There are around 10 small click sounds per every rotation. I'm just wondering if anyone knows what it could be.

I've tightened the chain ring bolts and the bottom bracket a bit but the problem is still there.

Does any one have any ideas?

Seems odd that there's no click on the other front gears.

Cheers!

Look at the front shifter metal cage. Is the chain touching it? It is the most likely problem. It may be more apparent with certain gears  in the rear than with others.

If yes, shift to the middle in the back. Try to turn the barrel adjuster on your left shifter one way and back. Does the noise change? It should and you should be able to find a position where it does not rub.

After doing that you may need to adjust the limit screws for the inner and the outer chainring.


When engaging the brake lever: the cable loosens and doesn't stay in the other side (where the twisty bit is) Picture inside. Bike newbie here, Tried adjusting v-brakes from rubbing but now when using the brakes this pivot piece pops out (instead of going back in). Why is this happening what are my options here? thanks!

The cylinder in there is not aligned, not sure if that matters? I tried to align it but it will not stay put (from wear?). Front brake is the same story.

It looks to me like you are pulling too much cable. It even looks like your brake lever is close to being able to bottom out against your levers. In normal operation, brake levers do not come out nearly as much as you have as in the picture.

First thing to check is to make sure your brake pads are not worn out. If they are, replace them. Then re-adjust your brakes so that you have as little clearance as possible without any rim rubbing. If your wheels are so out of true that doing so is very difficult, it would be worth resolving that.

Then, check your brake arm tensioning spring. This will help pull on the cable and to keep the cylindrical cable end seated in the slot on the brake lever. See if you can move the spring to a higher tension setting. Your frames brake post should have three holes in it, you can adjust the tension by removing the brake arm and replacing it with the spring in a different hole, and your brake arm may also have a tension adjustment screw to fine tune it.

And just as a sanity check, make sure the cable isn't slipping through the cable binding bolt when you hit the brakes.


Chain and derailleur question I inherited a Motobecane Nomade with no derailleur. I am trying to replace the missing derailleur and chain. I was given a Shimano SIS Tourney rear derailleur long cage and front derailleur and shifters that I was like to mount on the bike.

Two questions:

Is that derailler feasible for this bike?

I have a PC 1051 10 speed chain. Will that work or can I use a KMC X8.93 6 7 8-speed chain or is some other chain is needed. If so what?

It depends on the rear wheel you are using. Specifically how many gears. Also you need to make sure your shifters (if they are indexed aka have a 'click' for eachgear change and are not infinitely adjustable ) match the amount of cogs on your casette/freewheel on the rear wheel.

If you are using non indexed/friction shifting you can use these shifters with any number of gears in the back (In my experience).

In my experience 9 speed chains can be used with 6-8 speed casette and also work alright on 10speed. Have not tested it for 11 speed. So in general if your chain isn't too wide (it doesn't rub against the neighbouring cogs of the casette/freewheel and it isn't too narrow (the chain easily and fully seats on the cog teeth without having to force it on) you should be fine.

In my experience and according to Sheldon Brown Shimano rear derailleurs can be used interchangeably with other speed rated Shimano rear derailleurs. So a 7s rear derailleurs can be used for 10 speed casette when using the correct shifter. Do make sure the chain properly fits the casette's chain guide wheels. In some cases you might have to install longer limit adjustment screws in the rear derailleurs to be able to properly adjust it but in most cases you won't.

So to answer your question: yes that derailleurs should work as long as you use a friction shifter or a properly matched (same number of speeds as your casette/freewheel) indexed shifter.

Sheldon Brown: https://www.sheldonbrown.com/speeds.html
More complex explanation: https://www.sheldonbrown.com/derailleur.html


Why fixed-gear for track racing? I have what seems like a really simple question, and yet I didn't manage to find the answer.

Why do track races require fixed-gear bicycles, as opposed to single-speed freewheeled bicycles? Is it purely for traditional/historical reasons, or is there any good reason for that requirement?

A lot of mystique grows up around the regulation of many sports. The key (as Neo says) is to get to the source ...

UCI regulations say

  Section 2: bicycles

  Preamble

  Bicycles  shall  comply  with  the  spirit  and  principle  of  cycling  as  a  sport.  The  spirit
  presupposes  that cyclists  will  compete  in  competitions  on  an  equal  footing.  The  principle asserts the primacy of man over machine.

  ...

  1.3.025

  Freewheels, multiple gears and brakes are not permitted for use on the track during competition or training.

See UCI CYCLING REGULATIONS GENERAL ORGANISATION OF CYCLING AS A SPORT PART 1 GENERAL ORGANISATION OF CYCLING AS A SPORT (pdf).

The main reason behind this rule is safety. Crashes are, and always have been, common in track racing. Anything that can drop onto the track is forbidden. Freewheels and gears can drop oil, or otherwise fail, causing a crash. Gears (currently) always have some loopy control cable that could entangle another competitor.

Brakes are unnecessary because of the closed environment and the use of fixed wheels. Levers and cables can fail, and brake blocks can come out. In any case they would add weight to the bike, which would cost time in sprints.

So in general it's all about minimising equipment failure possibilities, and maximising the competitor vs competitor aspect.


BMX racing with a full size MTB? There is a local BMX track in a suburb of the town I live in. I had called there before asking about scheduling and rules and whatnot. I found out, that (at least on that track), they had a special category for bikes (such as full-size MTBs) with wheels bigger than 20".
Is this just this track doing it, or is there officially another class of racing for bikes with big wheels?
Thanks

There are a large number of tracks that have a Clydesdale class, which typically runs on 24" or 26" wheeled bikes. Most pump tracks aren't designed wit a 26" wheel in mind. It still is a lot of fun.


Shared bikes - what makes them robust? We see a proliferation of bike sharing services. Given that most shared bikes are kept outdoors all the time, I wonder what components and designs help to make them robust in order to keep maintenance cost down.

Here is a number that I found hard to believe, quoted by Horace Dediu on Twitter: Chinese dockless bike sharing companies employ one maintenance worker per 1000 bikes. Western dock systems are close to one per 30.

Addendum: From the Financial Times 26 Dec. 2017 "China bike-sharing apps find UK market tough to crack": According to Mr Seal-Driver, in Cambridge there are 23 operational staff for 450 Ofo bikes. Steve Pyer, UK general manager at Mobike, which does not employ people directly but uses third-party partnerships, says there are about 10-15 people for every 1,000 of its bikes.

Mass - resists denting and damage.  Some are steel, some are aluminium.
Single-speed - a lot of city bikes only have one gear, and those that have more are often euro-IGH (internally geared hub) with 3 speed, no more.  Either way they have 1/8" singlespeed chains.
Chainguards - to keep the chain and pants clean.
Robust lubricants - intended to not wash out.
Tyres - fairly hefty, large, and puncture resistant means fewer flats.

And the big one:

Ongoing maintenance  You may not see it, but the company will do ongoing maint of their bike fleet.  Most of the apps support some kind of "report a problem" so that the fleet staff know where to go to find and fix the bike.  Those that don't have etiquette

Cultural factors will come into it as well - suspect there are more vandalistic yobs in the west than in China.


How to measure the size of a suitable tire for my bike? If I have the diameter of the rim of my bike and also have the width o this rim, how can I determine which tire is good for me?

Measure the diameter of the bead seat (i.e. the place where the tire bead will sit).  It will most likely be one of these:

559mm = MTB 26 inch tire.
622mm = 700C (a.k.a 29er)
630mm = 27 inch that is old enough to remember the Bee Gees.

If it's not one of those, look it up here:  http://sheldonbrown.com/tire-sizing.html#iso

The new tire will have a marking on it like 28-622.  That second number is the diameter.


Will a threaded post rim brake pad fit my brakes which take a thread-less post pad? I found these pads on Amazon and I really like them, but they are a bit different than my current pads. They are threaded and the ones I have now are threadless. If I tighten them would it fit on my brake?

Here are the brakes I like.

Here is what I currently have.

Is it possible to make them fit? Thanks.

No it won't work well, I would not try it either... is injury worth saving a few dollars? Why not just buy the compatible parts?


What tools do I need to replace my bottom bracket? I have an old 2001 Schwinn Homegrown Pro that I want to upgrade to a 10-speed drivetrain. I'd like to do it myself as a learning exercise, but I'm not sure what kind of tool I need to remove the old bottom bracket (or to install the new one, for that matter). The crank is a Deore XT Hollowtech FC-M751, but I am not sure what the bottom bracket is.  The original specs of the bike are at this page

http://www.bikepedia.com/quickbike/BikeSpecs.aspx?year=2001&brand=Schwinn&model=Homegrown+Pro#.Upj1FMRDspU

But it lists the bottom bracket as "unspecifed."  It's dark in color and has inside-facing splines, but there are no obvious markings on it.

So, what do I need in order to remove this?

As this is an older octalink crankset/BB you will require a:

Crank Extractor like this to remove the cranks.
Bottom Bracket tool like this to remove the bottom bracket.
Dust cap removal tool (if it has these) like this
8 or 10mm hex wrench for crank bolts.

This is likely to require a lot of effort to free up after 12 years so I'd recommend a repair stand.

For fitting a new 10 speed crankset (at Deore, SLX, XT etc level) it's likely you'll need to move to a threaded external bearing BB such as Shimano BB70 which will probably come with the crank set you purchase. This requires:

External bottom bearing tool like this to install the bottom bracket and no other tools.

I was on the Park Tools site so used their tools as examples, many brands make similar tools. They also have a good reference section to learn how to work on a bike here.

Personally I would recommend trying to borrow the tools to remove the BB from your LBS rather than purchasing new as the standard for mountain bikes has changed to (many different) external bearings systems. It may end up you purchase them for this job and never use again....


Is it possible to use a 9 speed rear shifter with 11 speed cogs/cassette? Is there a disadvantage? I'm new to biking and I plan to upgrade my bike, but with limited funds I can only upgrade the wheelset and cogs(cassette).

Is it okay if I add the 11spd cogs but my shifter is only 9 speed (limited funds for now but will definitely buy a 11 shifter.)

What will happen?  Will it be OK?

It depends.

Rear derailleur lever geometry, shifter cable pull and clicks amount control rear derailleur lateral movement amount. Let's assume that there are 11 cogs with distance of 10mm between each other and derailler moves 10mm every click. 11 speed cassette might have the same width, which means 10% lesser distance between cogs, so it's 9mm. When otherwise 10 speed configuration would shift over such an 11 speed cassette, some gears are going to shift kinda successfully because 10% over one step might not introduce much of positioning error. But over ten shifts the error would be equals to one whole speed, so issues are bound to happen somewhere. I've used non-real-life values for example purpose. These differ between manufacturers and individual part models.

The said above also means that it might be possible to find components combination that allow you to use rear derailleur and cassette designed for different amount of speeds. Some real life examples:

SRAM mtb 9 speed shifter makes Shimano 10 speed mtb rear derailleurs compatible with 9 speed cassettes. There's no shadow+ for 9 speed, so some people choose this option because of price or weight.
Shimano 10 and 11 speed rear mtb derailleurs are compatible.
It's possible to modify existing derailleur so it moves less or more. Some people has modified 10 speed Shimano mtb derailleurs to work with otherwise 9 speed Shimano 9 speed drivetrain. Basically, they've routed the cable through hole drilled slightly closer to the cage, which changed lever geometry. I think the same can be done to increase the lever length with some spacers.
The shifter indexing cog can be replaced. There are some companies that shift such cogs that transform 10 speed shifter into 11 speed. DIYing cog should be possible too.

In your case, without modifications and assuming you are going to run same manufacturer components, 11 cogs would cause poor shifting with jams or skips. I'd rather not do that, but if you are mechanically talented, you can always try luck with existing gear mods.


What's this mark on my chainstay? I was cleaning my road bike (cannondale supersix evo) and noticed a marking on my chainstay and I'm not sure what it is. Scratching it is a little rough compared to the carbon around it. This was not there before

I did take my bike into the shop a few months ago, since the wheel was sitting really close to the non-drive side chainstay, and they said it was a non issue. This was when it only had a small scratch. Now it's turned into something like this.

Should I be concerned? I have a big ride coming up and don't wanna miss it!!

Here are some pics:

I have a Cannondale Supersix Evo and I've had issues with tires rubbing in that exact spot.  The frame will accommodate a 25mm tire, but the clearance is very tight, so you really have to pay attention to keeping the wheel trued up.  I've also found that the stock wheelset (Mavix Aksiums) flexed enough when I'm cornering hard to cause a little rubbing even when the wheel is near-perfectly true.  For a little while, I put some protective tape on the chainstays (I used ISC Racers Tape), but I eventually just switched back to 23mm tires. I like the ride quality of the wider tires, but replacing the protective tape periodically got to be a bit of a hassle.

To answer whether or not it's safe to ride, it LOOKS like it's just through the paint. If that's the case, cover it with some protective tape to prevent it from rubbing into the carbon, and you should be good to go.


Can't get the drive side bottom bracket cup out I have an older Raleigh frame that I converted to a fixed gear and the bottom bracket cup on the drive side has been painted over a few times and I can't get it out.

This is the type of cup (the one on the top left):

I've tried brute force (lost some skin on my knuckles) and it didn't even budge. Does anybody have any tips to get it out?

The drive side on most bottom brackets is reverse threaded. That means you have to turn it clockwise to loosen it.  If you don't care about destroying it, and are just going to replace it anyway, you can try this trick that I found, which seems like it would allow you to get a lot more leverage.