The front tire of my Huffy 3 speed rubs against the right fork as it spins The front tire of my Huffy 3 speed rubs against the right fork when it spins.

Hmmm. Thats a bad thing. You want to fix that.

Most likely the front axle isn't centered in the fork when tightened down.  I'm guessing you have axle nuts and not a quick connect skewer?  You want to loosen both nuts, hold the tire centered underneath the headset (where you can easily see that the gap between the tire and the front fork is the same on both sides.)  Then carefully tighten the two nuts holding the axle to the fork (I think you need a 15mm box / open wrench for this.)
Its possible the rim is out of true so when the axle / hub is mounted straight the rim is off to one side or the other.  Generally you see this when there are loose or broken spokes.  Tool to fix this is a simple spoke wrench and a whole lot of patience.
It's possible you have loose or missing wheel bearings at the hub.  When you spin the wheel is everything buttery smooth? Is there any noticable slop between the axle shaft and the hub? If so, that will have to be fixed (need more tools here, including a very thin hub wrench, grease, cleaner, possibly new bearings, etc...)


What is Speed Lockout on a SUNTOUR fork? Looking at entry level SR SunTour suspension forks, there are the options of

"MLO" - mechanical lockout
"HLO" - hydraulic lockout
"RL" - remote lockout

Now, mechanical and hydraulic lockout is clear. Remote lockout - not so much - it says that it is engaged from the handlebars, not from the fork itself.

My forks says XCR 011 Series mg. On the side of the knob is written "Speed lockout". I am able to lock the fork while compressed, but if I do it uncompressed, there is some small damping still, which is very nice.

How do I know what is this "Speed lockout" thing, without disassembling the fork.

Note that I have been unable to identify the exact model of the fork.

Remote lockout means that the fork has a "remote" lever that is installed in the handlebar.

My fork is a XCR RL from 2011 as well and pressing the blue lever locks the fork, pressing the black lever on top of the blue unlocks it. This is a XCR from 2011 as well.

You can see the remote in the following picture:

If you have a knob with speed lockout you should have a fork similar to SF11 XCR LO 26". If your fork has rebound adjustment then it's a XCR LOD. You'll have to look that up in Suntour's site since I can't post more than one link.

Browsing Suntour's Tuning Base may give you additional information.


Bottom bracket with built-in internal hub - does this exist? I've heard that one can install a bottom bracket that has what is essentially a built-in internal hub, giving one the ability to add a virtual double chainring where there's only one. This would be designed to be used in concert with whatever gear cluster or internal hub you have installed in the rear.

If this is true, does it exist in this form, or have I heard of a distorted version of the device? What are the advantages and disadvantages of such a bottom bracket?

The Schlumpf drives have been around for several years and incorporate a two-speed planetary gear drive attached to the bottom bracket. With the heel of your shoe, you tap a small button centered on the end of the bottom bracket to engage and disengage the planetary gear. Three models are available: a "mountain gear" version that lowers whatever other gears you have by a factor of 2.5; a "speed gear" version that raises your other gears by 1.65x; and a "high-speed gear" version that raises your other gears by 2.5x. The Schlumpf drives have been marketed to specialty bicycles such as folding or recumbent bikes that use small diameter wheels, and thus can have difficulty getting "normal" gearing using off-the-shelf components. Schlumpfs have also been installed on unicycles which (obviously) are ordinarily a single fixed-gear.

An advantage of the Schlumpf drive is that with only one chain ring, there is no need for a front derailleur and the chain line is straight -- and one can tap the button to engage or disengage the drive even while stopped. However, despite the straight chain the Schlumpf drive appears to be less efficient in terms of power transmission. Measurements suggest that the Schlumpf drives "cost" about 5% extra in drive train losses. Since conventional derailleur systems range from around 92% to 97% in transmission efficiency (see for example, the work of Kyle and Berto here), an additional 5% loss can be a considerable cost.

Pinion has brought an 18-speed gearbox to the market, the P1.18. It isn't a "true" bottom-bracket with internal gears as is the Schlumpf -- rather, the gearbox is in a separate housing attached next to the bottom bracket, and it is not an "after-market" solution that can be easily added onto an existing bike. The Pinion is intended for downhill or freeride bicycles that are purpose-built around the device.


Different vibrating tone on a belt drive with a Shimano Alfine hub I have recently bought a new Cube EXC Travel bicycle with a Gates carbon drive. This bicycle is equipped with a Shimano Alfie 8 speed internally geared hub. The bicycle is new and it seems that the supplier did properly check and adjust all parts of the bicycle before shipping it.
After a month of everyday riding (about 500km), I have noticed that I am sensing a different vibration while pedaling on the 4 gear (the middle gear). For some weird reason, my legs "vibrate" from the pedals on the bike in a different tone on the middle gear. Once I go up to the 5th gear, the vibrations turn smoother and that is why it is so noticeable to me. These vibrations are practically not felt when going down to the 3rd gear as well. The general feeling is that the belt "grinds" more when on the 4th gear than any other gear.
These vibrations do not seem to compromise my speed or acceleration when on the 4th gear. The yellow markings on the internal hub form an almost straight line while on the 4th gear. I suspected that belt tension might be the cause but I made sure that the belt is at about ~37Hz (going by the Gates application).
Should I worry about it? Is it common? Is it an indicator that something is wrong or that some parts should be inspected in a deeper manner by a professional? Or maybe it is just standard behavior? (unfortunately there aren't many belt experts in my area)
I believe I experienced minor skipping for maybe 3 times in 500km, I suspect this is not connected.

Try more tension on the belt. It will help with the skipping problem and a tighter belt will change how the belt vibrates.

For internal gear hubs Gates recommends 35 – 50 Hz
Montague Bikes - Adjusting Belt Tension with an Eccentric Bottom Bracket

Based on this article you are adjusting the belt just 2 Hz more than the minimum.
This gives you some wiggle room to experiment with. Try 40 or 45 and test for changes.

I think, perhaps, the #1 problem with the Alfine 11 is belt drive. Lots of Alfine 11 bikes come stock with Gates. Not a single belt bike I have ever worked on came in with the belt tension high enough.
Sheldon Brown - Additional comments by Aaron Goss (toward the bottom of the page)
Note: the Alfine 11 is similar to the 8


Can I install a front derailleur for my bike? I just bought a Micargi RD-7 with 7 speed Shimano Tourney rear derailleur. Now, I want to upgrade my crankset from single chainring to three chainrings for better hill climbing. Is it possible to do that? what front derailleur and crankset should I buy?

Shifters          :  Shimano SL-RS35-7R/LN 3x7 Speed
Rear derailler    :  Shimano RD-TX35  , 7-Speed
Chain                 :KMC 1/2"x3/32

I would say on this bike you can install any cheapest aluminum crankset, cheapest front derailleur and a friction (non indexed) shifter, where the crankset will be the most costly part (about 30$) and a few dollars for derailleur and shifter (each). So if you able to do the work byself you will end under 50$ for all that upgrade (but those should be done well), however if you want LBS to do the work it should cost about 20-30$ more (I don't really know the work costs in other than my regions).

EDIT:
As Batman mention in the comment, your BB can be too short for triple crank. If it is, the upgrade can't be done without replacing the BB too.
I didn't include tools cost in my answer.
And to get this work done you have to have appropriate knowledge.

As bikes have different width seat tube, your derailleur must fit it. If your frame tube is thin (and it looks that this frame has thin tube) you can take a little wider derailleur and put a holder plates between it and the frame. Of course you should check that the derailleur will be compatible to your crank teeth count.
It may seem difficult, but in LBS will be done easily. But you should compare it's cost, and cost of a new bike of same quality with front gears.


What are the ridges seen on sprockets and chainrings for? I've always wondered what these ridges below the teeth on sprockets are for. Can anyone enlighten me?

They are there to help facilitate shifting. Basically, the ramps you see help when going from a smaller to larger sprocket by catching the side plates of the chain to help the chain be pulled up onto the larger cog.

Another place where you will see atypical teeth is in the front; some are shorter/different shaped than others to help shifting as well. Sometimes you see pins as well.


Rear wheel rubs frame after tire change I recently changed the rear tire and paid no attention to the original working state of the rear derailleur. After a miserable attempt at resembling, I lost what I now think was the Derailleur bolt and nut (one flat side, curved elsewhere) during a short ride. It's since been replaced with whatever nut and screw I could find laying around.

Like the first attempt (with all the original parts still available) at reattaching the wheel, after a hard pedel, especially uphill, the wheel will move from centered. The tire rubs against the frame creating enough resistance to make pedaling feel impossible.

The rear dropout has a small screw hole and a large triangle cutout. I cannot find a configuration that allows the derailleur to screw into the small hole, and so am fastening it using the larger triangle.

Is the placement of the derailleur the problem? Do I just need to turn the nuts holding the axle on a little harder?

after the axle has slipped down:

You've lost the derailleur hanger mounting nut. Don't worry, they're dead cheap. Without it the hanger won't stay in place without the wheel nuts done up tight. You can get away without one (see matt's answer), but it's not ideal. It's better and less fiddly to use a proper mounting nut:

The way you've set it up now is totally wrong - the triangle-shaped hole is just a cutout in the rear dropout - it isn't designed to have anything mounted to it. I presume the other hole of which you speak is a mudguard or rack mounting eye.


Can the SRAM Rival 1 rear derailleur be used with an 11-46T cassette? I want to put the SRAM Rival 1 group on my next bike. Somewhere I heard that the rear derailleur can handle 11-46T cassettes despite the official documentation.
Is that true?
Are there any limitations for the chainring?

Having fitted a few of these, it works on some bikes better than others. I think this is to do with derailleur bolt drop distance. The derailleur can struggle shifting in and out of the 46.
I have had more success using these derailleurs on 11-46t 10sp cassettes with 10sp shifters where the margin for error is better.
The size of the front ring doesn't matter as long as the chain is the right length.


Any chance of identifying this tandem. (S/N T9012 737) Could be other numbers under cable guide. Manufactured around 1990 I think Need to identify this tandem likely manufactured around 1990.  S/N T9012 737.  Could be additional numbers under the cable guide.

[

According to this thread Bob is correct. His bike is a Gary Fisher Gemini. The tandem in the thread is a good match for Bob's bike.

From the thread

  I ran into a former Fisher employee at NAHBS this last weekend and was asking him about the tandem. All he could tell me was that the early ones were made in Mexico and weren't very well made. I suspect that yours and mine are later, Asian made bikes as mine, at least, seems reasonably well made. I'm still trying to figure out who designed it and decided to use the "uptube". I suspect that was the cheapest, easiest way to build it. Ritchey still uses the uptube design in their tandem, though Santana insists it makes no sense. At least it gives you a place to put a water bottle. The placement of the stoker seat tube cage won't allow the use of larger modern bottles. We use a clamp-on handlebar mount for the second stoker bottle. -- fxsvelo

later

  Serial number on mine is 19012-0707. It has (mostly) Shimano DX components; the catalog scans I've been able to find show Suntour XC on the 91-93 models. So maybe mine's an '89. Guess it doesn't matter too much!  -- rcschafer

I suspect he's wrong about the serial number based on the picture in the original question - it's probably T9012-0707

According to the Fisher catalogs for 1989 and 1990 the Gemini had a Shimano Deore II drivetrain. The Gemini was first sold in 1989, the last year was 1993. Fisher started using a Suntour derailleurs and a Sugino crankset in 1991.
Seems like Bob has a 1989 or 1990 model.


Why isn't my suspension bouncy? I recently bought a Carreras centos limited edition mountain bike. I want to find out how to make my suspension bouncier and I want to experience a MUCH more comfortable ride. I have tried fiddling around with the knobs that say preload on them but it isn't making the ride any different. I am quite small and I don't know whether that is affecting the suspensions bounciness. Please help.

Bouncyness* may not be the appropriate term for the behavior you need from your suspension.

Suspension has two main functions: Shock Absorbing and Dampening. Shock absorbing is what the fork does by compressing, allowing the wheel to travel upwards. In this process, kinetic energy from the shock is used to compress either a coil spring or an air spring. Once this has happened, this energy that is "stored" in the spring has to go somewhere, and this happens when the wheel is forced down again.

If no other mechanism is in action, this energy returns almost at the same speed as it was put in, so it would be transmitted to your hands through the handlebar, giving an unpleasant and dangerous ride. That's where Dampening comes in. Dampening is a mechanism that slows down the shock absorber's return, consuming the stored energy, usually transforming it into heat.

Most forks achieve dampening by having oil reservoirs, pistons and valves. The fork moves oil from one reservoir to the other (from one face of the piston's head to the other) and the flow of oil is partially obstructed by the valves. The oil gets heated a little bit as it is forced through the valves.

With this in mind, we can understand the two main adjustments that any decent fork should have. Preload and Rebound Speed.

Preload is HOW STIFF is the suspension, and it's related to how much force must be applied to compress it. More preload means you need more force (apply more weight) to compress the fork by a given distance or travel. Speed Rebound is HOW FAST the fork return to it's uncompressed size after absorbing a shock.

If you feel that it takes too much force to compress your fork, it means you have too much preload. You mention you are too small (not heavy enough) so it's likely you must turn the preload all the way to the side marked with a minus sign (-).

There is a process to calibrate a fork, and it needs a ruler and possibly an assistant. You must measure SAG. Sag is the amount of travel that the fork compresses by just applying  your weight to the bike in riding position. The user manual for your fork model should contain a table indicating the appropriate sag range for your weight. Preload is adjusted to achieve the desired sag, the more preload, the less sag and vice versa.

Chances are you weight too little for that fork. If this is the case, there may be some options: Change the spring, or change the fork. Some fork manufacturers sell different springs for some of their fork models, precisely to suit too big or too small riders. Refer to the fork owner's manual, It should bear the information. If you don't have the manual, It may be available from the manufacturer's web site.

If the fork is not serviceable or a softer spring for it is not available, you can change the fork for another one that fits your weight or that can be adjusted accordingly. An AIR fork  may suit perfectly, since the "preload" of an air fork is given by the pressure of the air in the chamber, which obviously can be lowered to zero.

There is no preload adjuster on an air fork, but there is a valve for adjusting air pressure. They often require a specialized pump to load the air chamber and calibrate it. If you have a local bike shop near you they should be capable of swapping the forks and calibrate the new one.

You must also take into account that you have a front suspension only bike, so you will feel almost zero suspension effect for shocks to the rear wheel, so depending on the terrain you ride, you must learn to act as a suspension for yourself. It also depends on the purpose of your ride: sport, leisure, commuting... as this allows you to choose routes accordingly.

A limited option is to use lower tire air pressure, but not to low. Too low pressure may result in a bike that is not very maneuverable and prone to "snake bite" flats.

*A bouncy suspension can be understood as a faulty one, it is a suspension with no dampening or rebound control. It does not absorb the shock, it just stores its energy for a very little while and then returns it. For example, a car without dampener keeps going up and down after hitting a road bump, or you see its tires bouncing like a basket ball after a pot hole. A suspension with this condition is risky because it allows the tire to loose contact with road, leading to loss of control of the vehicle/bike


Inconsistent headset tightness and squeaking I own a Trek 1.5 road bike, purchased new around June 2012. The headset (original, never replaced) has recently been experiencing some interesting issues:

About 4 weeks ago, the headset began squeaking much more than normal and became stiff to the point that turning the front wheel was very difficult. Wrenching it from side to side would free it for a little while, but then it would resume the behavior fairly quickly (10 minutes of riding or less). I took in in to my LBS, they said "huh, odd," checked alignment, lubricated it, and said I ought to be good to go.

Things worked well for about two weeks of light riding, but then the behavior resumed- first the headset started squeaking more, then the steering stiffness returned. After turning the front wheel side-to-side for a little bit, the stiffness left and was replaced by a very loose feel. This loose feel and non-squeaking behavior stuck around for about 10 days, and then a few days ago, the headset started tightening up again and squeaking very obviously.

I'm interested in potential explanations for the symptoms observed and potential fixes. The reason I'm coming here first is because I'd like to have some more information before going in to the bike store for the second time- I'm after a permanent fix, not just a check/lube/out the door. My guess is that something's wrong with the bearing unit inside, but I'm not sure.

STOP RIDING THAT BIKE

I'm concerned that your bike has internal problems and that something may fail rapidly (ie, you're experiencing the warning now)

You need to inspect the front steerer tube and head tube looking for anything wrong.

Firstly, clean and inspect the frame area around the headtube.  You're looking for cracks or any damage.
Take photos of how its assembled before starting, as a visual guide.
Start by removing the stem, either quill stem if its an old style or the top cap and stem if its more modern.
Hang the bars out of the way so there's no pressure on the brake/gear cables.
Remove any spacers, or undo the lock nut and crown nut.
pull out the bearings.  They may be in a cage (easy) or there may be dozens of tiny loose ones.   Put them aside to wash in degreaser.
Drop the fork down and out the bottom.  Be aware there's more tiny ball bearings in the bottom, again may be caged or loose.
Clean grease off, and inspect the

steerer tube - the "handle" of the fork.  It should be straight, with no cracks or deterioration.  You should have a good look under a bright light, and use a steel ruler to look for any bends
fork crown - the bit that joins the tines/legs/blades of the fork to the steerer tube.
Ball bearings (look for non-round ones, discoloured ones, or chipped ones)
Bearing races - the running surface that the balls roll on.  These should be clean, smooth and bright.  There should be no dents or dips or damage.  There will be four, two in the bike's frame, one on the bottom of the fork, and one on the top big nut.
Head tube - use a torch/flashlight, and look down inside the frame for anything wrong.

If everything seems fine, clean and grease and reassemble in the reverse order.  You might like to fit new ball bearings at this time, they're pretty cheap from the nearest LBS.  Getting the tension right on the bearings can be a bit fiddly, but it should be smooth with no play when fully assembled.

You might benefit from removing the front brake or its cable.  Removing the front wheel will make it easier too.

Once completed, it should be perfect steering, provided there's no damaged parts gone back in.  If you find damaged parts please update your question with clear photos.


Why does my chain slip off the chainring when cruising or back pedalling? My bike is a little more then a year old (although I do put a lot of miles on it, about 12 miles a day), this problem seems to have started about a week ago. It's a 7 speed Avilon Next (a cheap brand but works well enough).

What's happening is while I am riding, if I stop pedalling to cruise or back pedal (I know, why back pedal? Perhaps I'm near the curb or what ever, that's besides the point! It shouldn't happen at all!) the chain gets way too much slack, and then falls off my chainring. I'm not sure if it's something with my derailleur, or perhaps cassette (possibly my free hub?). But I think I've narrowed it down to one of those two.

Any help or advice will be great, thanks! Sullivan

Sounds to me like classic symptoms of a dirty drivetrain. If your chain is getting slack on top when you stop pedalling or backpedal, then the problem is in your freehub (or freewheel, whichever you have), a dirty freehub will cause all the problems you've listed, even on a brand new bike.

When dirt and grit mixed with excess chain oil get gummed up in the bearings of your freehub, it looses a lot of it's freedom to move. The easiest way to confirm this is to take your wheel off, and just try to give the cassette a flick with your fingers, if it doesn't spin freely, then it is certainly gummed up and the easiest thing to do is get the freehub replaced (freehubs aren't easy to clean unless you have a freehub buddy). You can clean a freehub without a freehub buddy, but you'll have to take it appart to do a good job of it, and there are lots of tiny bearings (~42) in a freehub that are easy to loose, so if you're not mechanically inclined, I wouldn't recommend trying it. If you want to try, you'll need a freehub tool to get the freehub off the hub, and another to open the freehub (their different depending on brand of freehub), I also recommend getting a pair of snap-ring pliers and a magnet tray (pliers for snap-rings obviously, and magnet try to prevent dozens of tiny ball-bearings from going everywhere).

How to Prevent Sticky Freehubs

Proper oiling and regularly cleaning your drivetrain is the best way to avoid this problem. Over-oiling is the biggest culprit for sticky freehubs, don't just keep applying more oil to your chain, always wipe off the excess, and clean you chain regularly to remove dirt and grime, simply oiling isn't enough.

Riding your bike as often as you do, you should probably be getting your drivetrain replaced at least once a year (Chain and Cassette) as wear and tear will also give you problems.


Difference betwen two rear derailleur? What is the difference between these two rear derailleurs?

On the pictures it seems, that the "rotation angle" is different.

https://bike.shimano.com/en-EU/product/component/tourney.html

On the item descriptions, all details are absolutelythe same.

If the specs are identical, then they are functionally the same. There is no 'rotation angle' spec - the body of the derailleur rotates around the 'B pivot' and these two just happen to have been at slightly different positions when they were photographed.

The product names suggest the FT55 is slightly better than the FT35, but I don't think there is really any difference in quality between components in Shimano's Tourney range.


Starting again my 9 miles challenge I had to quit cycling a couple of years ago and now I am back. I started cycling to university 9 miles one way which took me 1.30 hour. I know it's longer than what it should be, but I've just started.

I want your advice please: what food should I look for healthy energy?  I can't walk now, my knee kills me ... is that normal?

Any other advice?

9 miles should not require any changes to your diet, excluding extreme temperatures or excessively mountainous terrain. Your knee hurting is likewise not normal. Your bike may be a poor fit, or you may need to learn to use a lower gear: spinning the pedals faster, with less force required on each stroke.

Neither fatigue nor knee pain should be an expected outcome of a short, low-intensity cycling trip, particularly for someone of typical university age. If either of these persist, I would strongly recommend consulting with a physician.


Removing a rear wheel of a town bike I'm a beginner in repairing bicycles. I have quite an old town bike. I'm trying to change the tires. I have trouble in taking out the back wheel. As you can see in the picture, there is a small piece of chain connected into the hub shell.

I've checked for a small clasp or small screws to remove it but it doesn't seem to have any. Does anyone know how to remove this? Or am I doing something wrong? Any help is appreciated.

This picture shows a slightly better angle. You need to first loosen the lock nut slightly, then spin the adjuster barrel until it unscrews right off the threaded rod on the chain. When you re-assemble you reverse that, and have to re-adjust the tension so that it shifts properly.


How important is tire tread on a mtb used for commuting? I started back riding a bike around town last year, although I don't have a $600 mtb or road bike. I'm finding out a lot of interesting things that I took for granted when I first starting riding my old 10-speed back in the 70's, like tires and gearing. I was 15 years old when I bought my first 10-speed, comparing now to then, the bike has come a long, long way. I'm relearning everything I thought I knew about a bike and finding out that I don't like road bikes per say, reason being that I like off-road riding once in awhile and a skinny tire can't do that for me.

"Importance" is highly subjective, debatable, and relative. But, based on the limited information in your original post, and a lot of assumptions about you, I'd say: tire tread is only of moderate importance. Unless you're really pushing the limits of the tire (very fast aggressive cornering, etc.) you can make most common tire types (mountain, urban, cyclocross, road, etc.) work for commuting.

Some factors to consider:

Commuting on mountain bike tires isn't usually super efficient, but can often be much more 'comfortable' than skinny road tires. This is because mountain bike tires tend to offer more cusion (due to higher air volumes and lower air pressures). Mountain bike tires often have higher rolling-resistance (when compared to narrower, higher-pressure tires) on pavement.
There are circumstances in which mountain bike tires have less 'grip' on pavement. This is if/when the tires are especially knobby (big, spaced knobs have less surface area contacting the hard pavement).
The trade-offs to these disadvantages is that mountain bike tires are generally better off-road, for those instances when you aren't on pavement.

Many commuters have found that a mid-width, semi-slick tire (i.e. something 30mm-45mm wide without significant knobs) ends up serving as a good/solid/comfortable on-pavement tire and also allows for sufficient off-road use.


How much does it cost to race in the Tour de France? Assuming one makes it onto a pro team that's been selected, I was wondering how much it costs per rider to race in the Tour?

I'm interested in the set cost for each rider to race, if there is one, and also how much (approximately) it actually costs the team to put the rider through, taking into consideration all the ancillary costs like bikes, mechanics, team busses and cars, food, lodging, etc.

It's hard to come up with an exact number, but you could likely get a team in for $10 million dollars or slightly less.  The figures I have seen for "average" budgets are usually around $20 million.  Most estimates place over 50% of the budget in salaries, with larger name riders making more.  A Tour de France team is 9 riders, however, pro teams generally consist of more riders and the best 9 (currently available) are chosen for the race if the team is invited.  However, a UCI pro tour team needs to have a minimum of 25 riders and a max of 30.

Officially there is no "cost" ,per se, for racing in the Tour de France.  Teams are invited.  However, the costs are associated with getting a UCI licensed pro cycling team, which must have a full time staff and meet minimum requirements.  Theoretically a person with near magic insight could assemble a team of unknown riders and staff for around the $10 million minimum.  However, it's likely that if the team did well enough to actually be competitive, riders and staff would be snapped up by teams with larger budgets the next year, likely gutting the team.

For a minimum 25 rider team, you are probably looking at ~$2.5 million for minimum rider salaries and salaries for a staff plus UCI fees (severely lowballed).  That's roughly $100K per rider and wouldn't cover travel costs, facilities or anything else.  ~$10 million sounds closer to covering all those things.  Or roughly $400k per rider for your 25 rider squad, only 9 of which you will send to the Tour de France.  As asked, the question is difficult to answer, because although you may need roughly ~$400k per rider for your Tour team, you have to have an additional 16 riders on staff to be considered for invitation (all at the same minimum cost).


what should I do when single track gets narrow There are some trails I ride on regularly and I've seen many people go each way. A few times the single track gets very narrow and I was wondering what should I do when I see a biker coming towards me? There is also an about 50 foot cliff on one side and a fence on the other so I wouldn't have anywhere to go. Should I turn around and go back to a section that was wider and let them pass? Otherwise the trail is too narrow and won't allow two bikers side by side.

Edit
I live in Orange County California

Any ideas?

Presuming you cannot see the other rider before entering the narrow section (if you can, wait for them to pass through), going back is not my first choice - as others have commented, if there's enough room to turn a bike around, there's enough room to get past - even if it means both dismounting.

Given most riders are human and can communicate even if they speak a different language, some form of dialogue should quickly come to a solution that meets the needs of the specific situation and individuals involved. Its also rare for very narrow sections to last for more than a few yards - perhaps "backing up" to a passing place would be quicker and easier.

If there is not enough room for the bikes to to be passed around, and its too far to back up.... you could offer to swap bikes and meet up next week, same place, same time...... Especially if his bike is nicer than yours.


Need help understanding wheel sizes Wheel Diameter: 64cm/25 inch what does this mean? I'm thinking of buying a new bike. but Ive never heard of 25 in wheels. Or is the 64cm a 700c. I've only had 26 in up till now and my knowledge in the cm is next to none. can anyone help me please?

Having a look at the link provided in the comments the wheel make and model is pretty clear. Following a swift Google search the same wheel is advertised on Amazon as a 26".

https://www.amazon.co.uk/Hybrid-Front-Wheel-Knives-Dx3000/dp/6254401010

So, any 26" tyre  should fit you fine, although I'd be questionable of the seller, as mentioned in the comments above.


Bottom Bracket - Drive Side is Stuck, what to do please? I'm trying to remove a sealed cartridge BB. I've removed both cranks and the non-drive side (plastic) came out fine.
The drive side is stuck solid - I know it's reverse thread on the drive side and I have the correct tool(s).

I only have a basic tripod work stand and I've been whaling on it very hard but it wont budge at all! I'm thinking of longer lever arm with a piece of pipe or something.

Any tips or suggestions would be greatly appreciated.

What's your frame made from?  If its carbon, might be time for the LBS.  If its steel then start with easing oil for a couple of days followed by a leverage increase using your pipe.  The main danger is exerting too much force and stripping threads.

I'm assuming the cartridge is toast which is why you're removing it.  If its a beater steel frame, you might get some motion using heat on the outside of the BB, which should enlarge it fractionally, but will adversely affect your paint and any nearby plastics.  And it can set fire to the easing oil or grease, so keep a multi-purpose extinguisher or bucket of sand handy.

When you do get it out, remember to grease (if steel) or whatever coating is appropriate for alumninium/carbon.


What is this part called? I built a new YT Capra yesterday, and it had a part I had not seen before. It was not mentioned anywhere in the instructions, but it was needed to get the rear mech the correct distance from the rear mech hanger.

See in the image below, in the red box. It is a kind of spacer between the rear mech and the rear mech hanger. If I didn't use this, then the mech would hit the frame.

I haven't got a picture of it on its own. It was a small ring with a notch on it. That notch lined up with the notch on the hanger to give it an extra couple of cm. I'm wondering if this is something YT have built especially for this edition (it is not on older ones), and it doesn't exist anywhere else?

That's part of the derailer. Most SRAM derailers have a piece like that. They're not really supposed to come off and float freely but sometimes they do anyway. There's not a specific name for it, but if you wanted to buy a new one for this X1 rear derailer, it's part of SRAM pn# 11.7518.014.000, "XX1/X01/X1 Rear Derailleur B-Bolt and Limit Screw Kit".


Riding mountain bike to work regularly? I have a womens Magna Glacier Point that a friend gave to me (I'm sure that's probably a low grade target brand). I recently got a job about a mile from my house, but there's two steep inclines I have to ride (one going down and the other going up) and I've found it's difficult to do.
I know that there's different types of bikes (fitness, commuter, etc.), would it be better to get a hybrid or some other bike, or are there modifications I can make to my current bike to make it a little easier to ride uphill? Or should I just tough it out and build those leg muscles and not be a wimp?
Thanks for any advice!

It's hard to get a better bike than a mountain bike for going up and down hills.   Even a cheap one.  The geometry is set up so it's controllable both up and down steep hills, and the gearing almost certainly goes low enough that you'll be able to pedal up even the steepest of hills (as long as you're strong enough to push the combined weight if you, your bike, and all you're carrying up that hill...)
For going down steep hills, as long as you're not trying to set any speed records you just have to be able to stay in control.  (I'm ignoring brakes overheating on long descents here...)
For going up steep hills, as long as the bike is geared so you can pedal it up the hill fast enough to stay upright, the only thing that really matters is the combined weight of the rider, the bike, and everything else you're carrying.  Shaving weight off even the cheapest and heaviest of bicycles won't make a huge difference here, and even the cheapest, heaviest mountain bike probably has low enough gearing.  Shaving just 5 lbs or 2 kg from a bike can get expensive.  The easiest place to lose any weight is to not carry anything heavy.  The next easiest place to lose weight is you...
One thing that can help is using either toe clips or clipless pedals to allow you to also pull up on the pedals.  That will allow you to engage more muscles as you climb and that could help take some load off your quads and glutes.  Note, though, you'll still have the same cardiovascular limits on how much total power your muscles can produce.
Finally, though, it's all about you and your fitness and strength.  Those will both improve as you ride more.  The ride will get easier and/or you'll go faster.


Is it best to put oil on the inner or outer of the chain? When I oil my bike chain, I oil the inside and the outside like so:

     1. Oil here ▼
  ___________________
 /                   \
 | 2. And oil here ▼ |
 \___________________/

Cycle on 1/4 of the length of chain, and repeat 3 times, so that the top and bottom all the way around has had it applied.

Is this overkill? Do I need to oil both sides of the chain?

If you think about it, the purpose of oiling is to lubricate where you have metal moving against metal.

So in the diagram below:

you need to oil the pin/roller area. There's no point oiling the face plates (which I think is what you're saying?).

When you oil, know how many links are in the chain (or mark your start link), and go around the whole chain once, oiling each roller. That's all you need to do. No need to do quarter turns or repeat three times.

Then, when you've done, wipe off the excess oil with something dry. A bit of rag or kitchen towel will do.


Coaster brake suddenly not working (Nexus 3-speed hub) My girlfriend took her bike out for a spin and noticed the coaster brake wasn't working at all. Instead of braking it just back pedals, not like a free hub, but if you back pedal the bike actually moves backwards.

While I know quite a bit about racers/time-trial bikes, I have no idea how to fix this. Does anyone here know what I can check/do to fix this?

It may be a broken brake shoe, or possibly a broken clutch spring. This usually happens when the axle nuts are not tightened to the correct torque (30Nm), or the wheel is put back on without the non-turn washer.

Take it into a shop that has a Shimano dealer account. If you want to fix it yourself, they can order you the entire internal assembly (it comes in one pre-assembled piece, part #1 on this diagram). Make sure you emasure the length of the old axle, and order the same sized new one. With some minimal work (this link), you can remove the old assembly, pop in the new one, and get your girlfriend back to riding.

NOTE: The above video shows how to remove the coaster brake shoes. You are not trying to do that! Simply replace the entire unit.

If you'd rather not do the work yourself, a shop shouldn't charge too much for it, and the work will be warrantied as well. They can also check the hub for any other damage.


How do I know which derailleur I need? The derailleur on my sons mountain bike is mangled, how do I know what to replace it with?

I understand they aren't one size fits all.

There are 6 sprockets on the rear cassette and 3 on the front.

If you have a six-speed rear cogset the bike is either inexpensive or seriously old; such things have long since been replaced by 7-8-9 or 10-speed gearsets.

At any rate, the important thing with a rear DR is "capacity".  It must have sufficient arm length to handle the range of gears on the cassette or freewheel.
Most all DRs have sufficient side-to-side movement, so the factor you're looking for is the length of the "arm" with the two rollers on it.
Longer arm, more capacity.
If you look at high-end road bikes with very "close" gearsets, you'll see the arm is very short.   Look at mountain bikes which have great big low gears, and you'll see longer ones.

Also... Cheaper DRs such as found on many "box-store" import bikes often mount on a steel piece that is bolted into the dropout. (where the axle goes)
Better DRs mount on a "hanger" which is often replaceable; these may have a different mounting screw.
Just take the old one with you to the bike shop and they should be able to find a good replacement.


Where to mount a headlight if the handlebar is obscured by a basket I have a permanently mounted basket in front of the handlebars (because I have a child seat on the rack in the back). I also have a headlight on the handlebars (this one, if anyone cares). If the basket is empty, it is somewhat visible, through the mesh that basket is made of. However, if I put anything in the basket, the headlight is useless.

I should mention that I also have a dynamo powered headlight below the basket, but I turn it on only when it's really dark, as the bottle dynamo noticeably slows down the bike.

Any ideas where to move the headlight from the handlebars? To the fork perhaps? That can be a problem as it would point a bit upwards then, and also would be partially obscured by the wheel itself.

Something like this accessory is what you need:

Can be fitted onto wired or meshed bicycle baskets.
This specific model is made by the "Rixen & Kaul" and can be found in many online shops. E.g. Amazon - Rixen & Kaul Light-Clip Basket Fitting - Black.


can you put a shimano XTR M980 175mm stage power meter on a XT M785 175mm setup? I would like a stages power meter on my set up but cant figure out if the bottom bracket sizes are correct and if even the new crank will fit at all?

Both the M785 and the M980 are hollowtech II systems and compatible. They use a compatible bottom bracket sm-bb70 and sm-bb93, which are English threaded 68/73mm.

The M980 uses the same clamping system as other Hollowtech II systems which is different to earlier xtr cranksets which required specialist tools.

The stages power meter comes as a replacement crank arm with the meter built in, so while this set up would work for aesthetic purposes wouldn't it be better to get the m785 meter?


Disadvantage of Hybrid Bikes on Mountains Everybody know that Hybrid bike can be used for mountain cycling. But I want to know what are the disadvantages if we do so? And what are disadvantages of using mountain bikes in cities.

Since a hybrid is a combination of two or more types of bike characteristics, there are many possibilities, and you should consider what aspects of the particular bike where meant for the mountain or for the road and see if they meet you needs.

Tires

You can use almost any tire, provided your frame has the clearance needed. Wider tires can be safely used at lower speeds and also provide a contact patch with a larger area, both give better rolling characteristics for off-road riding (more traction, shock absorbtion and lower rolling resistance on rough terrain). The rougher the terrain you want to ride, the fatter the tire you want.

Some Hybrid frames won't accept tires wide enough for serious MTB riding. On the other hand, a wide frame and fork can accept the thinnest tire that fits your rims.

Drivetrain

Generally, MTB requires low gear ratios to provide mechanical advantage for ascents on rough terrain or for extreme climbs. On the other hand, Road riding requires high gear ratios to provide high travel speed while keeping the cadence (pedal rotation speed) relatively low. Commuting requires a mid range gearing, which you may modify towards any of the two extremes depending on how hilly is your city, your style and physical condition.

A road drivetrain may not have the low ratios needed for off road riding. Generally speaking, the same slope is rideable faster on pavement, thus you can use higher gears. An offroad slope has many smaller obstacles like roots, stones and terrain irregularities that do not allow the use of high ratios.

A secondary disadvantage is that larger chainrings get closer to the ground and so, are more likely to hit obstacles like logs or big stones.

Mountain drivetrain is normally good enough for smooth commuting. For a flat city where you don´t need higher speeds it means that only the mid-range gears would be used. The low gears may come in handy if you commute on a hilly city with steep climbs.

However, for high speed road riding, you may run out of gears.

Frames

Traditionally a road frame has an horizontal top tube, this reduces standover clearance. (distance between the top tube and the crotch of the rider while he or she is standing with both feet on the ground). Some hybrid bikes are designed like this. On mountain riding you usually need greater clearance, making this a disadvantage of certain Hybrid frames for MTB use.

The other disadvantage may be that the hybrid frame may not be properly reinforced to withstand the high demands of serious MTB riding or may not accept upgrading certain components, like a fork with suspension (or greater travel).

On the other hand, MTB frames tend to have sloping top tubes to provide better stand over clearance. While this is not properly a disadvantage for road riding, or commuting, the lower top-tube and seat tube junction also lowers the possible mounting points for rear racks, (if any) which in turn may reduce the possibility of fitting one. This is a disadvantage only if you need a rear rack with medium to high load capacity. (Because there are seat post mounted rear racks with limited load capacity).

Suspension forks and frames.

Some hybrids have mountain geometry but rigid forks. These can be used on light offroad use, specially for prepared trails that have been smoothed out. And for city riding if the city has good infrastructure (no potholes at least).

A suspension fork with around 100mm travel is good for any riding you can do on a hard tail frame (non suspension frame). It's excellent for trail riding and for cities where potholes are common or if your riding involves a lot of getting on and off curbs.

If you don't have a fork with suspension blocking, you should at least have one with preload regulation and rebound control. Higher preload and slower rebound setting than used for mountain riding helps to reduce pedal bob, thus improving efficiency for city riding. The same goes for using suspension frames for city riding.

A suspension frame is very unlikely to have mounting points for rear racks and complete mud guards.

My personal experience

I have successfully commuted on a very hilly city and made two 500+  kilometers rides (with around 100 km stages) on a hardtail mountain bike with slick tires, an air suspension fork, 3x9 mountain drivetrain, straight handlebars and a seatpost mounted rear rack.

The low gears (22/34) have been a blessing on steep roads or when I get really tired. On the high end, my 42/11 top ratio has been enough for the speeds that my training level allows me. The straight handlebar provide only one hand position, which causes hand and wrist strain on long rides.

The mountain fram geometry allows for a more upright position. This proved good for the back o my neck, since being 4+ hours on a bike at a time caused pain on my peers that where riding road bikes.

The thin, slick tires are so great that I can almost roll as easy as my road counterparts, but they are not as skinny as theirs, so I get slightly more comfort on rippled or highly cracked asphalt and more confidence against potholes.

The air fork allows me to easily tune it, using higher pressure to reduce pedal bob, since it doesn't have locking. The rear rack is very useful for light loads, but it vibrates a lot more than a frame mounted rack.

Another advantage is that my frame has v-brakes that perform a little bit better than regular road brakes.

My bike fits my needs closely because I didn't bought it as is, I have changed many components over the years. The only change I want to make now is to incorporate a road or a touring handlebar. (but I don't want to change my brakes or shifters...).

I'm currently experimenting with a rigid fork and bar tape on a riser (MTB) handlebar.

Bottom line is that bikes have so many components that the possible combinations are almost endless. There is no possible way of making a bike that will excel in all types of riding, let alone one bike that fits everybody's needs.

This means that any bike will have disadvantages for certain type of riding, so it is up to you to define your needs and pick the bike that most closely meets them, experiment, research and decide whether changing some component is necessary and possible (considering budget and compatibility) to make your particular riding better.


Approx age of my Vindec I have just bought an old Vindec Ventura, With 27x1 1/4 wheels 32x630 rims. It looks like a hybrid but wondering if it was a sports updated. Any one any gen at all on this modelCheers all.

Answer:: 80's road bike with modifications

I'm guessing its an 80s road bike that has had the drops, quill stem, shifters and brake levers swapped out for a flat bar from a more modern MTB.

That's a gorgeous steel lugged frame

No bottle mounts are in the frame, which is why a PO has fitted a strap-on bottle cage.

Frame pump mounts also went out before the 90s, as did the uselessly-short mudguards.

That rear light looks like its powered by D batteries. so will be heavy.  I'd swap it for a pair of efficient LEDs, for safety when riding at night, unless you're trying for a period bike.

The cranks are cotterless, so its no older than the 80s or that was also changed - there's a triple chainring, which may have been fitted with the MTB bars or may be original.

There may be more info in the rear cluster/cassette and the rear derailleur, and the brand/model of brake calipers.

If it runs okay then air up the tyres and ride it.  I'd suggest changing all four brake pads, and examine the tyres for deterioration.

If the tyres are getting iffy, consider replacing the whole wheel with a more common 700c aluminium rim.  Those 27" wheels look like chromed steel and wet weather braking is wishful thinking!  Downside of this is the brake calipers may no longer reach a slightly smaller wheel and may not have as much pressure under braking.


Jump start electric bike? I bought a Huffy electric bike but I don't have charger. The person at pawnshop where was bought said I can charge it with a car, like jump start.

DO NOT DO THIS!

You can't safely charge any battery using jumper leads from another battery. If the other battery matches the flat one, but is fully charged, the current will be so high that you will probably start a fire. You will definitely damage the flat battery, and probably both of them. Jumper leads work on cars by having enough resistance that the flat battery survives, but you should never leave them hooked up between two batteries in an attempt to charge one from the other. Car batteries are also designed to supply very high currents, so can accept high currents without too much damage. Bike batteries are not like that.

The main problem is that electric bikes, even really old ones, normally run at 36V, some older ones at 24V or 48V, but a single car battery is 12V. At best a car battery charger will do nothing for you. If your electric bike is old enough to have a series of lead-acid batteries (that work in a similar way to car batteries), a car battery charger might be able to charge those one at a time without damaging anything.

If your bike is a more modern one it will use lithium batteries and you won't be able to charge it at all with a car battery or battery charger. Unfortunately, if you open the battery case up and attempt to charge it, you could easily set the whole thing on fire. Look up some of the videos of hoverboard fires if you want to see what happens.

You really need to find the correct charger and use that. You can probably buy one from Walmart, but you may have to find the spare parts section on their website to do it.

I will edit this answer to be more useful if you can supply more details.


Are there any 'anti-car' bicycle companies or shops? In the UK it would be a brave company that took the 'anti-car' stance when it comes to selling bicycles. Furthermore, most cycle shops, distributors and others connected with the trade are personally quite pro-car (the mechanic fixing bikes to pay for his car which he needs to get to his job fixing bikes is the classic, the accountant of one distributor driving a Porsche takes the biscuit). Then there are the customers, generally most of them are pro-car (even if necessary evil) and you cannot alienate them, can you?

Are there any companies in the bike business - large or small - that are quite open with harsh opinions about the motorcar? Or have there been, only for the business model to fail? Is deference to motoring a reality that cannot be escaped?

Well, there's the Cars-R-Coffins website, but i don't know of any shops that are actively anti-car.

It's pretty counter productive, and even if you push the green dream pretty hard, it's generally recognized that positive input is better than negativity.

For example: Most people respond better to, "I ride my bike because it's good, cheap transportation, and environmentally sound." than they do to, "Stop killing the planet with your 6 mpg Hummer H2, you inconsiderate #$@%!*..."

There are advocacy organizations that will push the line pretty hard, but retailers and wholesalers have to maintain balance a bit better than that.

FTR, I don't think you are insensitive to this, i just think it's an answer that you pretty much stated in your question.


Shifter Options for 105 3x9 upgrade I am in the process of upgrading my road bike from 3x9 Sora FD/Tiagra RD with Sora shifters to 3x9 105 FD/RD.  Any suggestions on shifter upgrades?  Derailleurs have been replaced, have new SRAM  9spd cassette and chain, all work OK, but would like different shifters to finish improvements. Would any newer 105/Ultegra/Dura-Ace be compatible, or should I focus on a hunt for a decent used set?

Current 105/Ultegra/Dura-ace are more than 9 speed, so you can't use them. Plus, the old 105 or tiagra 9 speed shifters you'll get are probably the same as the current Sora shifters anyway, due to trickle down technology (just with tiny modifications and a price premium).

So, in short, if you're sticking with 9 speed, don't bother -- you'll just pay more for a different sticker on the shifters.


Looking for a waterproof electrical bicycle, is there such thing as ip68 for electrical bicycle? I'm currently trying to find a bicycle brand that produces electrical bicycle with ip68/ip67 waterproof.
Currently I could find any, google is not helping with my search and when I find something there is no information about to what degree the bicycle is waterproof.
So my question to the community, is if there exists electrical bicycles with a good waterproof protection that would allow me to commute to work in heavy rain conditions?
Best,

None of the name brand e-Bike motor manufacturers makes a motor intended for use in a bicycle that is also rated for continuous immersion in water.  (IP67 is a rating that it works when completely underwater, not that it is rain resistant....)
Some manufacturers do claim an IP65/6 splash resistance rating, particularly for hub motors.
Mid-drive motors are a little trickier since they are just a component that gets integrated into a frame by the builder and the manufacturer doesn't necessarily control the final product you get.  None of the three big brand names in pedelec mid-drives claim a specific IP rating for just the motor unit.  However, they have certainly all proven fine to ride in the rain in practical experience!  (Best to not leave parked outside in the rain with water pooling on components though.)


Which tires are best for on and off road use? My tires are worn out so I want to change them.

When I am trying to change them, I want them to be to the best fit for the conditions I cycle in. I cycle about 30 km a day on roads ranging from smooth pitched roads to very rough roads consisting of pits and stones in the most haphazard way.

Please suggest a type of tire that would be best for me. There do not need to be considerations for snow, it does not snow where I cycle.

What you are looking for is a hybrid tire with not enough tread to be a nuisance and slow you down on the road, but enough tred so that when you go off road you are not losing traction on gravel and mud.

For example Bontrager makes a hybrid tire that is nice:

Also, go with the hard wall tires whenever you can. they cost a little more, but they are more puncture resistant. So they will cause you less grief on the road.


What's causing my thumb tremor after riding? After asking this beginner's question, I took people's advice and started test driving bicycles. I rode for about twenty minutes, so not too long. About fifteen minutes later, I found that my right thumb had developed a serious uncontrollable tremor. Whether I clenched the thumb or relaxed the thumb, it kept shaking. The left was not shaking.

I test drove two bikes (both relatively upright): one where the hand grips + brake handles fit well (though I didn't have padded gloves so that caused some pain) and the second where the brake handles were far enough from the hand grips that I could only reach them with my finger tips. I returned quickly with that bike because it hurt and I didn't feel safe being unable to control the brakes well.

I had ulnar nerve problems with that hand/wrist twenty-odd years ago, though the ulnar nerve numbness ran from my pinkie and ring fingers up to my neck and didn't involve my thumb at all.

Is the thumb tremor simply a result of bad-configuration-for-me handles? Or is it a symptom that I haven't ridden in forever? Was it the lack of proper padded gloves? All three?

The lack of padding on your gloves is unlikely to have been the problem in such a short ride. The lack of grip in adverse weather conditions is more likely to cause it. You mentioned that you were holding the bars very tight. With typical stock handlebar grips it's perfectly possible to apply a lot of pressure on the nerves at the base of your thumb, and this can cause numbness and loss of control.

The good news is it should get better fast. When I've had this issue (often sweaty hands and unexpectedly rough terrain) it's faded within a couple of hours. Others report it taking a bit longer.

There are several things you can do:

In warm/dry conditions bare hands have decent grip.
Bike gloves don't have to be expensive. My good gloves were under £/€/$10 on eBay.
Even minor changes to your hand position can relieve the pressure.
Riding one handed allows you to flex and relieve the other hand. It might seem unrealistic when you've just started riding but it's a useful skill, essential in traffic for signalling where you're going. Practicing riding with one hand while the other hovers near the bars is a good start and will help your hand.
Ergonomic grips spread the pressure, and provide more hand positions on flat bars. I've used the Ergon GP2 and GP3 with bar-ends on my hybrid, and they're good for riding all day.
Adjusting the bike to fit (especially so you're not using your hands to stop yourself sliding forwards all the time) will also help. This is something you can do yourself or with the help of a friend, but you'll need some longer rides to test it.

Finally if it doesn't get better within a day or so this time, or keeps coming back, you may need to get it checked out


pedal crank moves and tries to slip off the axle I changed the bottom-bracket in my mountain bike two years ago, the problem was that the bolt on the crank on the non-drive side was continuously getting loose, to the point that I had to stop and tighten it again every mile.

With a new BB the bike was all right, and it worked fine for almost two years (I wasn't using it that regularly though). Until last week, when it started having the same problem again.

The BB is a part of the bike that usually lasts forever, so I'm not really convinced about changing it again, because the current one lasted so short, I think there could be some other problem in the bike, that causes the BB to wear faster. But I haven't got a clue about what that could be.

Does anyone have experience or thoughts about it?

thanks,

My guess is that by the time the first bottom bracket (crank axle) was replaced the left side pedal arm was also damaged. When you installed the damaged crank arm to the new axle it worked for awhile. You are now at the point that you have a worn arm and a worn crank axle. Replacement of just one of the components will result the premature failure of the other. You need a new bottom bracket and crankset. As this is an expensive repair it may be worth looking for a used assembly that is in good shape. The crank arm bolt should be tightened to about 30-35 ftlbs of torque. This takes quite a bit of effort with the average 6 inch long allen wrench.


Dirt jumps with wood I am looking to build a dirt jump track and after realizing how much dirt is really required for a proper jump I am exploring using a wood frame to pile dirt on top of to reduce the need for dirt. I live in San Diego with little rain, so it seems this is as good a climate as there is to use wood without being overly concerned about the wood going bad or rotting or decomposing. My plan was to build a bridge more or less with about 18-24 inch "hand rail/walls." I would then fill the dirt in over the bridge up to the top of the wall (so the dirt would be about 18-24 inches thick) so there is a table top with a take off and landing I can sculpt. I was going to use pressure treated lumber when possible for structural integrity/longevity, set the posts of the bridge in concrete, and use sealed plywood where necessary. It seems this would be very solid.
If it lasts 3 years, I would be happy. I suspect it will last longer than that in San Diego. Questions:

Has anyone seen this/have any feedback?

Is 18-24 inches enough dirt to properly compact and hold? I would think so as I have seen small 24 inch tall jumps and they don't fall apart.

Any thoughts on pressure treated lumber lasting a long time in contact with dirt that will need to be lightly watered somewhat frequently? I've seen posts saying pressure treated wood should last decades in contact with the ground.

Thoughts?
Thanks,
MB

Properly treated timber will last decades in the ground. Wood treatments are generally rated for there preservation ability. Different treatments are used for protection from insect and moisture damage, and the timber is treated to suit the local conditions. Most countries have a set of standards - e.g. American Wood Protection Association for USA.
Some timber will last several years in ground with no preservative, and a lower level preservative treatment might last long enough for your purpose
As far as longevity - the problem really comes down to safety - who will know when the timber has degraded, who will check, and what damage will result form a collapse?.   Also you need to consider the construction methods - building something to last a few days is very different to building something to last a few years - do you have the wood working skills to be sure you will built the structure strong enough to last years of jumps.
While you could build a structure in timber, cost factors into it. You not only need timber, you need the fasteners and time and tools to build the structure. Dirt is cheap, and for jumps versatile and easy to change profile - most likely it will be much cheaper to get a truck to drop off the dirt you need to build the jumps,  but do cost out having the dirt taken way when you no longer want the jumps.  It your that way inclined, its also a decent an excuse to hire an excavator and have some fun...


How do I replace road shift levers? How do I remove my old (Shimano Sora) brake/gear levers and replace them with new (Shimano 105 5800) levers?

(This is the bike if you want to know more components details).

As a note, I'm asking about step-wise instructions on the technique/method, not technical issues like going from 9- to 11-speed as covered here (Upgrade Shimano Sora shifters to 105)

Remove cables.
Remove bar tape.
Roll back lever covers to reveal clamp bolts
Loosen bolts and slide off bars.
Follow instructions included with the new levers (these should in effect be a well written reversal of steps 1-4.)


SRAM AXS double to single I'm looking at a road bike with SRAM Force AXS 2x crank but would like it as 1x. I see from photos that the spider is separate from the right crank.

Are the 1x vs 2x arms and/or spiders different?

If arms and spiders are the same, I can just replace both rings with a single 1x-specific one. If the arms are the same but the spiders differ, I have to get the 1x spider as well, and if the arms differ I have to replace the whole thing. The seller don't do any customization so I can't ask them to swap.

I haven't done it, but I am pretty sure it's doable without purchasing a new crank.
SRAM shows that switching between AXS 2x and 1x is as simple as changing the chainring:

However, if you have AXS Wide 2x, it's 94mm BCD (vs. 107mm), so you will need both a new spider and a new chainring (AXS narrow-wide 1x chainring with 107 BCD).


Why do men's bicycles have a top tube while women's bicycles don't? Bicycles intended for men have a top tube that always hits me on that embrassing part when I brake.

Conversely, women's bikes often don't have a top tube. Why is this?

Frames designed for women do have that part - its called a top tube.

Historically women wore skirts, so a lower frame in the middle made it easier to mount and dismount, and was less likely to accidentally show an ankle.

This picture shows a modern "woman's frame" with the top tube paralleling the downtube, and attaching to the seat tube lower down.

Positives:

Skirts
Ease of mounting

Negatives:

Bike is flexier because of fewer triangles
Bike is built heavier to reduce flex

Another frame designed for with these positives is the Mixte frame, where the top tube is replaced by two separate tubes similar to chainstays and seatstays.  These pass around the seattube and terminate at the headtube and the rear dropout, increasing the stiffness of the bike.    They're still heavier than a normal Diamond Frame bike.

Here's a photo of a Peugot showing the twin tubes.

Finally - there's absolutely nothing wrong with a woman riding a DF bike frame.  The main differences now are about proportions, not whether the rider wears a skirt.  There are situations where a man fits a "woman's frame" better than a "man's frame"


Are all Shimano 10 speed cassettes compatible with each other? I am trying to buy a cassette for my new incoming carbon wheels so that I just switch them with my current wheeyl whenever I need to race/crit without the need to retune the shifter and derailleur.
I was wondering if a Tiagra HG-500 12-28t (10 speed) would be compatible with my current Tiagra CS-4600 (12-28t) 10 speed?  For a reason, it is really hard to find CS-4600. Thanks!

All Shimano and SRAM cassettes up to 10 speed are broadly compatible.

They all use Shimano's Hyperglide II freehub body spline pattern.

Cassettes with the same number of sprockets have the same sprocket spacing, sprocket width and overall width.

So, you can replace a N speed Shimano/SRAM cassette with any other N speed one that has a range compatible with your drivetrain (min and max sprocket size and within total capacity).

At 11 speed Shimano and SRAM road and mountain drivetrains diverge in sprocket spacing, but retain compatibility within those two categories.

The chain length may need to change but a new chain should be used with a new cassette anyway.

FYI you may find you need to adjust your derailleur when swapping wheels, as the two hubs wont quite laterally position the cassettes identically.


Can you trim rim tape once installed? I installed my rim tape then noticed was too wide so I trimmed it with a razor knife. Would this have caused any damage to the rim bead?

Probably not, depends how careful you are and if they are carbon rims.

I always do a 3cm test to get the best width, then take my time and gracefully cut the width of the entire roll with a cutter.
Now you have a entire roll of the correct width and you just apply what you need.


Can Di2 only be tested as a complete setup? I'm having problem testing my Di2 setup. Long story short, I got a pair of used but in very good condition Dura Ace Di2 9070 brifters for a cheap price. I then bought a new Di2 cable set with external battery mount, external junction SM-JC40 and the SM-EW90 junction A. For the RD I bought an Ultegra R8050 RD, also in a very good condition since the shop said they just took it off a new bike. The batteries are the SM-BTR1 with around 50% charge, as indicated on the junction box when I plugged the cable into it. Currently I'm missing an FD.
Now the problem is I want to test whether the setup works out of the box without firmware update so I plugged everything in, checked the connection etc, but the shifter isn't doing anything and the RD doesn't move. Holding the shifter button also doesn't show the battery level. So my question is: Is it normal for Di2 to not work without the left shifter and FD connected? Or is it really a firmware problem?
Thanks in advance.

Okay problem solved. Apparently the NOS cable set that I bought came with an SM-EW90-A with really old firmware. After installing E-Tube Project v3.4.5 and restarting my laptop, I was able to update the junction box using SM-BCR2. The RD works without the FD mounted and I was able to make initial adjustment while waiting for the FD.
Thank you for all your comments and hopefully we learn something new everyday!


Rear Derailleur wire sags completely in higher gears I have a Shimano 7 speed rear derailleur which used to work properly. Lately I observed I was unable to shift down to gear 7 from 6 but let the problem be. The derailleur would move very little (there wasn't even any grinding sound against sprockets when shifting).
Now the gear won't even shift from 4 to 5. Derailleur works fine till gear 4 but as soon as I shift to gear 5, the movement is miniscule. I checked the wire and it was all slack (literally hanging with 0 tension) in this position. Clicking to shift down to 6 or 7 doesn't even produce a clicking noise and there is no effect on wire/
derailleur.
I have read about wire tightening (per this question) but those steps require chain to be on lowest cog. My wire goes all limp in gear 5 and chain is on fourth sprocket. Can I undertake the tightening procedure in this situation? How do I gauge requisite wire tension in this case?

What you describe suggests friction in the rear housing loop. It fits with the problem getting progressively worse, and with the apparently slack cable, presumably along the downtube or chainstay. This can happen from corrosion, contamination, kinks in the cable/housing, or the housing or cable fraying or coming apart.
It might need new cable and housing. That is normal maintenance and not a big deal if so.
Put the shifter in 7 and leave it there. Pedal with one hand while pushing the derailler inward up to the big cog with the other. Use the slack you've created in the cable to slip the rear loop out of its stop. Try to slip it up and down the cable to inspect for friction. Inspect it for the above. If it's dirty or corroded, get it clean. Put a few drops of oil along it. Shove the derailleur inward again as you reseat the housing in the stop. See if there's any improvement. It would be normal to need to readjust the tension at this point.
If the bike has a housing segment near the seat cluster, it could also be the source of the problem.


How many miles and/or commuting seasons will a modern internal geared hub last? I've been considering drive trains on a utility / commuter bike.

The Shimano Alfine internal 8-speed hub is on several bikes I've liked. I've also heard good things about SRAM and Nexus hubs.

I ride in a wet / nasty winters / fairly flat environment here in Minnesota.
I'm partial to lower gearing if it meant more reliability or lower
cost.
I don't need max efficiency
All other factors are secondary to durability in my eyes.

As I’m not current on how much maintenance can I expect a modern internal hub to require, and how long will it last before needing to be replaced.

What are expected or actual lifetime / maintenance needs of modern internal hubs?

I bought a 700c Jericho hardtail in 1997, which came with a Rohloff 14 speed internally geared hub. I used it as a commuter for five years, at least 150 miles per week, 50 weeks of the year. That's 37500 miles. Even assuming I took a week or 2 out in there for whatever reason, call it 35000 miles. After that, I continued to ride it one or 2 days a week, for less strenuous rides. I have just sent it back for its first major service, other than lubing and cleaning the external components.

The Rohloff is a ridiculously burly hub. The Alfine, or the i-Motion9 would do well to match half that performance. But I'd say based on people I've sold bikes with Nexus or Alfine hubs, and how rarely we see them for service, and how much more rare it is that they need major service, that 20000 miles is not too much to expect.

The Shimano and SRAM hubs are both user serviceable, unlike the Rohloff, which should extend the useable life significantly also.

I was trying to find any formal service interval information, but both SRAM and Shimano say that aside from cleaning off the external parts, the hubs are "well sealed" and the service interval should be "long".

Sheldon Brown's site also says, "Service should be quite rare on these well sealed hubs."


STI brake shifters for cantilever brakes? I have a Jamis Aurora 2016:

Jamis Aurora

I'd quite like to convert it to have brake lever gear shifters (the shifters are on the end of the handlebar drops which I don't really like). But will they work with cantilever brakes?

Does anyone have experience of doing this? Is it a lot of hassle?

Yes, they will work with most STI levers. Cantilevers and road calipers use the same cable pull. If you were ever to convert from cantilever to linear pull (v-brakes) then you would have to be more careful in matching them up.


Should I buy this (gently) used, 15 year old, helmet? My neighbor is moving cross country and selling all his bike stuff. His helmet's a white Bell, about 15 years old. It's a bit scuffed but generally in pretty good condition. The only thing that worries me is some of the styrofoam is cracking off, but it shouldn't be hard to glue or remove and stuff a sock in the hole. And  the right side is a bit deformed inward from storage (he says) but it bends back when on my head. But the straps are fine and it buckles great, plus it still looks stylish after all these years. He's selling it for $10, which sounds like a steal. Should I snag it for cheap or splurge on a new one?

No. It is safety gear – buy a new one.

The old helmet might make a good pot for a hanging plant but it is more likely to fail dramatically in your moment of need.

The straps would probably come right with a soak in water, but the polystychrene is the functional part and it has failed with age.

It might fill a legal requirement if your location mandates helmet wearing, but it probably won't provide sufficient protection.


What are the consequences of riding a bicycle tire backwards? When putting a new tire on a bicycle, there is usually a note somewhere on the sidewall showing the direction the tire is supposed to rotate when you are on the bicycle.  However, the last time I changed my tire I already had the tire mounted on the rim and inflated before I remembered to check for this marking, and it turned out I had it backwards.  Rather than take the tire off and do the whole thing over again - or leave the tire to rotate "backwards", I opted simply to put the wheel on backwards, as it was the front tire and there did not seem to be anything dictating which side of the bike the quick release had to be on.

I have ridden about 20 miles so far without any issues, but I am wondering, what, if any, are the long term consequences of either this approach (riding with the tire backwards from the standpoint of the rim being backwards with respect to the quick release being on the opposite side from the back tire), or simply riding the tire in the opposite direction as labelled on the tire.  For the latter, I am wondering if it really makes any difference, because in my case I had to really search for the direction indicator as it was barely discernable.

I'm riding a road bike (touring geometry) and the tire itself is a long-life, hard casing type, as opposed to soft "performance tire" types which get flats more easily but are supposed to handle better.

If it's a road tire, i.e. a slick, it makes no difference. The tire direction marks are usually printed on road tires because mechanics are so used to looking for them, that the makers may as well put them on there so as not to confuse or waste the time of the installer.

http://sheldonbrown.com/tires.html#direction


Size 29×1.9/2.125 inner tube into my 700×40 I just put a size 29×1.9 inner tube into my 700x40 hybrid tyre. Is it safe to use? Thank you

2.125 is about a 54. That's enough mismatch that over long term use you could see the thing where the surface of the tube picks up a crinkled texture and it could maybe split and fail under pressure, especially if you're running high pressure, I.e. 55+ PSI. For this reason it's not really optimal, but it's a long term issue (probably years) if anything ever did happen.


Buy second-hand bike in or near Frankfurt I'm travelling to Frankfurt, Germany in the next month and I'll be staying there for three months, because my trip is related to work, I'm trying to know how to get a bike that I can use to commute, (My daily commute is to get to Bad Homburg) taking into account that my german knowledge is almost none (even thought I'm learning by myself right now), and I don't know how english (spanish or french) comunication is in the aforementioned city. I'd like to know what are the best known places in or near Frankfurt to get a second hand bike. It doesn't have to be a pro one, nothing fancy, I just want something useful at a reasonable price.

I actually grew up near Bad Homburg, and have bought a used bike there. (You do realize that depending on where in Frankfurt you want to go, the way there from Bad Homburg can be quite far?) The two biggest bike shops there are Fahrrad Denfeld and Fahrrad Diehl. At least some years ago, both of these shops sold used bikes as well, and for reasonable prices. I think I bought one from Fahrrad Diehl for 150€ that I used during my 5 years of studying

Communicating in English should not be a problem in either Bad Homburg or Frankfurt, especially with people from "younger" generations / who are < 50 years old


Switch front and rear tire for distributing wear Possible Duplicate:
  Should I change both tires when I need to change one?

On my road bike, my rear tire has much more wear as my front tire (reported by others on this site as well).

Should I switch my front and rear tire to distribute this wear evenly, or let the rear tire wear more and replace only the rear?

You may have flat-spots on the rear tyre and I am not sure whether I would want that on the front. Plus you will be spending a lot longer with the tyre levers if you 'rotate' them. Valves are a bit sensitive too - mess with the tyre/tube too often and the valves can 'waggle' out of the tube. Personally I would let the back one wear out and replace it when it is 'done'.

But this all changes if you are on a long-distance tour. If you were going from Sierra Leone to Somalia, dodging lions and land-mines, then you probably would not find too many places on the way to stock up on fresh Schwalbe Marathon Plus tyres. Therefore, on the long tour, you would do well to 'rotate' the tyres (giving them a good inspect) on a regular basis.


Basic toolkit for bicycle maintenance What should be in the basic toolkit for someone that wants to maintain their own bicycle?
I'm looking for something for your average day to day maintenance and tools that I will get the most use out of. Ex: I don't think I need a chain oil/lube/clean contraption...(do I?)

I have some hex wrenches, a few tire levers for changing tires, random screwdrivers, and pliers. Do I need a chain tool? Do I need a bike stand?  (I sometimes invert the bike and do tuning that way)

I would classify tools into two groups.  The ones you ride with, and the ones you keep at home.  There may be a bunch of overlap, but it is harder to work with a multi-purpose tool, so if you end up using one tool all the time, a purpose-specific tool may be worth the purchase.

Tools to carry with you:

Tire levers.
Patch Kit.
Multi Tool.

There are a plethora of these.  I'd suggest visiting your LBS to find one you like.
Should have all of the hex wrenches you need for on the route fixes.

Leatherman (optional).

When you need it, you need it.  Until then, it's just dead weight.

Tools for at home:

Hex wrenches (optional if your Multi Tool has them already).

Bikes tend to use hex bolts all over the place, so a nice set of these can make your life easier.

Regular wrenches (optional based on the bike).

Axel nuts, pedals, and a few other odd bits might use these.
I believe everything on my bike is a 15mm wrench.  So maybe just need one?
Also may be included in your Multi Tool.

Chain lube.

I prefer T9 lube, but I know a lot of people who run straight 30w engine oil.
Yes, you need lube.  Otherwise your bike will end up sounding like a hamster wheel.

Chain Cleaner.

If you ride enough that you are posing this question, you will probably need one eventually.  Road grime sticks to chain lube and can grind away at the soft internal workings of your drive train.
They're also pretty cheap and really easy to use.

Other Tools:

Chain breaker.

This is useful if you need to replace or shorten your chain.  Until then, it isn't really needed.
May be included in your Multi Tool.

Bike stand.

Almost never necessary.  Nice, but not necessary.
Most of my bike work is done with the bike upside down on the carpet at home.

Cone wrenches.

Really nice if you know how to adjust your bearings.  I don't, so I take it to someone who does when they are out of adjustment.

Bottom bracket tool.

Most of the time your bottom bracket will not need maintenance, so it is easy to take it to your LBS.

That is everything I can think of right now.


Can I fit a bigger cassette just by changing the hub and not getting a new wheel? I have an old 29er that came with a 7 speed shimano tourney groupset, can I replace that with a 9-10 speed new set, just by getting new hubs? or the wheel cant handle that setup? the frame needs to be "prepared" for that change too?

You may be able to get a 9 or 10 speed sprocket cassette on your wheel, if you have a freehub style hub rather than an older style freewheel. Its a common misconception that cassettes with more sprockets are wider, so the hub needs to be narrower or the frame needs to be wider, but actually the sprockets are closer together. 8, 9, 10 and mountain bike 11 speed cassettes are all the same width.

This does not mean you can convert your bike to 9 or 10 speed though. TL:DR - it's usually not cost effective to upgrade Tourney level bikes.

You would need to replace the cassette, rear derailleur, chain and shifters, very likely the  crankset, front derailleur and bottom bracket too. For 10 speed you would need to be at Shimano Deore. If you add in the special tools required, paying someone to install it all (or making the investment in learning how to do it yourself), you will find that the cost approaches that of a new bike.


Identify this hub (similar to a Sturmey Archer rear internal gear hub w/ drum brake) I recently came across the auction of  an old Gazelle city bike. It is equipped with rear internal gear hub with drum brake which looks like Sturmey Archer 3 gear hub. But this hub has two shifting cables (one on each side, going to the internal hub) and very strange shifters, which I guess are not original.

The auction description states that this is 3 gear hub.

I've seen Sachs Pentasport 5 hear hub with similar shifting design, so I suppose it might be something similar.

Please, help my curiosity and identify the model of the hub.

EDIT
on the handlebar I've noticed some kind of gear shifting instruction, which suggest there is indeed 5 gears.

Auction

Appearance is alloy shell and 70mm drum which would be a Sturmey-Archer AT 5 , which was made mid 80's thru late 90's with dual lever shifters . A version was also made with just 3 gears .


When is it time to replace my trainer tire My trainer tire has cracks running along the length of the tire. They cracks seem to go in pretty deep, but don't go all the way around the tire. However it still has quite a bit of rubber on it and doesn't seem to be worn too much. I also don't think I have put that much mileage on it, but it is probably 5 years old, but only used for maybe 20-25 sessions.
I'm using a fluid trainer so I'm not really worried about being hurt, but I'm wondering if I should worry about it breaking and coming off the rim and causing some kind of damage if it gets caught in something.

I wouldn't hesitate using a tyre in that condition on the trainer, in fact that's exactly the sort of condition i might expect to start using a tyre on the trainer.
The small cracks likely mean the rubber is deteriorating and may be less grippy, but that's of little worry.  It's very unlikely there is substantial damage to the actual carcass of the tyre.
Finally, the absolute worst case scenario is a small split begins, the tube pokes through and bursts - however positioned where they are there is very little chance of the beads becoming unseated.  So maximum damage is the embarrassment of explaining to people you got a flat on the indoor trainer.


Maintence on Mavic 500 hub without Mavic 670 tool I have a beloved but well used front wheel built around an old Mavic 500 hub whose bearings are finally starting to give up the ghost. If you hold the axle and spin the wheel you can feel it grind through a few spots in the rotation as well as hear a nice few clicks as the bearings stick in the cartridge's raceways. I'm pretty convinced they need to be replaced.

There is however a lock ring that is preventing me from getting the bearings out. There is a special tool (the Mavic 670) that looks like similar to a bottom bracket tool except it has six pins that fit into each of the six little holes on the hub's lock ring. I found a few of them on ebay for the reasonable price of $90. Needless to say I would like to try to get the lock ring off without purchasing the "rare and vintage Mavic Key 670 Bottom Bracket and Hub Assembly Tool".

I gave it a try with a spanner wrench but only succeeded in stripping out one of the soft aluminum holes.

Does anyone know if the lock rings are reverse or regular threaded? Any advice for trying to free them without using Mavic's proprietary tool?

Try carefully using an adjustable pin spanner, or the Park variant. If not, I believe current Mavic hubs use the same pin pattern, so the plastic tools that come with Mavic wheelsets is plentiful and may be strong enough for your use.


I'm changing from 8-speed to 10-speed will I need to replace my rear Hub? I've dug an old road bike out of the garage for the winter and need to upgrade the drive-train, I'm happy about most of what I need but but I'm not sure about the rear hub (an old Shimano Ultegra)..

..Will I need to change the rear hub/wheel to accommodate a 10-Speed cassette?

Answer: No you don't need a new hub.

However, you will probably need to put a small (~1mm) spacer at the back of the cassette, otherwise you won't be able to tighten the whole cassette down. Also be aware that prolonged use of a 10-speed cassette on an 8/9-speed freehub body will cause dents to form in the freehub body (because the 10-speed cogs are so narrow). The 10-speed freehub bodies have taller splines, so they avoid this problem (but don't work with 8- or 9-speed cassettes).


Why are battery-powered lights so popular? Both on this site and "in real life", battery-powered lights appear to be at least as popular as generator-powered lights.

I have always been slightly confused by this. To me, a generator-powered light seems the better solution if you need light regularly, because there's no need to worry about charging, and because they can be permanently attached. Yet many people seem to not only prefer battery-powered lights, they appear to not even consider a generator.

Why is that so? What are the advantages to battery-powered lights?

The main advantage, in my view, is that you can more easily add/remove battery-powered lights.

Why this may be desirable:

Theft resilience. I take my lights off the bike and carry them with me if I'm parking my bike outdoors for longer than a few minutes. Caveats: This can be more of a downside than a benefit, depending on your situation. (I can't imagine a thief taking the time to steal a generator-powered light, but I'm sure it happens sometimes.)
Flexibility. I don't bother to take my lights with me unless I know I'm possibly going to need them. If I used a generator-powered light, I would be pretty much stuck with it all the time, even if I'm only going to ride during the day. Caveats: This is, however, not much of a positive thing, unless the lights you use are particularly heavy, or you happen to be a "weight weenie".
Interchangeability. I can swap my lights between my bikes very easily. Most decent battery-powered lights have an adjustable removable clamp that you can use to attach the light to any style of handlebar/seat post/other tube that you could possibly want. This means that I only need one set of lights that I can use between all of my bikes. Caveats: If you don't like to spend an extra 5 minutes swapping your lights every time you want to ride a different bike, this is not a plus.


What is the significance of rear travel of a frame? Every suspension frame has the the following two parameters: shock travel and rear axle travel at maximum shock compression. I have a lot of questions, regarding those two:

What are they properly called?
They seem related, however for the same shock travel the rear travel can differ. I would intuitively guess that long rear travel for short shock travel would be best. However, this is not the case (I saw an expensive frame with less rear travel than a cheap frame). So what shock and rear travel would I want for different types of mountain riding?

What are they properly called?

Rear wheel travel (e.g 180mm) and shock travel (e.g 3 inches [76.2mm]).

  They seem related

Theoretically they are not. One could design a pivot system which would give 180mm of rear wheel travel with a 18mm shock travel. This would not work correctly though.

The ratio between the wheel travel and the shock travel is called the suspension leverage ratio. A 180 to 76.2 setup gives us a leverage ratio of ~2.36 to 1. Some companies (e.g http://foesracing.com/) claim that a lower leverage ratio (e.g 2:1) has significant advantages for downhill racing.

  So what shock and rear travel would I want for different types of mountain riding?

You'll only choose the rear wheen travel based on what you want to do. For example if you want to do downhill racing then 203mm is the norm. Whichever brand and frame you choose will come with a rear shock installed which has very specific size specifications, e.g 9.5x3 (that is eye to eye and shock travel in inches) and even if you wanted to change the rear shock you'd have to go with those specs.


How to select the fenders for my bike I inspected the tires of the bike and found their size: 700 x 40  - 28 x 1 5/8. Which probably means, that the diameter is 28 inches and the tire width is 40 mm (I measured with a ruler).

I found, that people recommend SKS Chromoplastic fenders and they have many sizes: http://www.ebay.com/itm/SKS-Chromoplastic-Road-Racing-Bike-Mudguards-P35-Black-/380993168162?pt=UK_SportGoods_CyclAcces_RL&hash=item58b4f66322

The seller says, that the fender is for 700C (which is probably my size), but the width is not specified. Maybe, 'P35' means 35mm tire?

Should I select the fender exactly for 40mm or buy a little bigger?

Mudguards can be measured in a few different ways, so different brands may vary. And it seems the SKS model numbers and names have recently changed, so some websites may still refer to the old names.

For SKS Chromoplastic, 'P35' refers to the width of the mudguard. For it to fit, the guard has to be a bit wider than the tyre, probably at least 5mm more. From the SKS website, the Chromoplastic 35mm is designed to fit a 700 x 20-28 tyre.

So for a 40mm tyre, you should look for a 50mm mudguard. Or a bit wider if your tyre is particularly wide or knobbly. SKS do make a Chromoplastic P50 (also known as 'Hybrid' size), designed for 38-45mm tyres, so that would fit fine. Or another option would be the SKS Bluemel B53, which is 53mm wide so fits 700 x 38-47 tyres.


Is the fit wrong on my road bike or is my body too stiff / inflexible? I am very confused about how to get a correct fit on a road bike. I am female, 5'5", average weight and proportions, and have a 31" inseam. Recently, I decided to buy a Specialized Ruby after trying out my friend's bike and noticing how smoothly it rides. I was told by one LBS that I should ride a size 51cm or 48cm bike but I feel stretched out. They said it's because I'm not used to the position. When I look at myself in a mirror on the bike with my torso making a 45 degree angle from the horizontal I don't feel comfortable. When I ride with that position on the demo bike I feel stretched out and struggling to support my torso at that angle though my arms don't lock.

Another LBS fitter is convinced that I need a much smaller bike and has tried to fit me on the 44cm. My arms do have a slight bend and I am sitting more upright and don't feel stretched out as much.

So, my question is--who is right? I am also thinking about trying out road racing, so getting the correct fit is crucial.

Honestly, whichever feels most comfortable to you is the one you should go with. Take both of them for as long a demo ride as the shop will let you and don't pay attention to how the fit "looks" in the mirror. Whichever frame you decide on, be sure you get a fitting from a reputable source - ask other cyclists you know to see who has the best reputation in the area.


Upgrading SRAM PG850 8 Speed Cassette on Defy 4, must Be Compatible with Claris Shifters I need to replace my SRAM PG850 8 Speed 11-32 Cassette & Chain on my Giant Defy 4 2015, due to general wear and tear, however I would like to upgrade to something a bit better though within budget (about £50).

*It needs to be Compatible with my Shimano Claris Shifters and Derailers.

Any suggestions or advice on what I should be looking for would be great. This is the first time I have replaced anything on my bike, so I have a limited knowledge of what parts go with what.

Almost any 8 speed cassette will be compatible with your bike.* As far as the chain goes, that more or less depends on the cassette.

As long as you stick to 8-speed, there are basically only two things you need to worry about.

Your cassette should fit within the range of your rear derailleur. Every derailleur has a minimum and maximum cog size that it can accommodate. Just check the specs for your derailleur and stay within that range.
Your chain needs to be the right length for the largest ring on your new cassette. If you get a cassette that has a cog that's bigger than 32 teeth, you will almost certainly need a longer chain. If your big cog is smaller than 32 teeth, you may need a shorter chain. The venerable Sheldon Brown has a great guide on how to choose the correct length for your set up. If you're unsure, just buy a chain that has as many links as possible (at least as many as your current chain) and remove links as needed.

In short, any Shimano or Sram 8-speed 11-32 cassette and chain will work without any issues. If you're changing the range, just check your rear derailleur compatibility before you buy.

*The one major exception to this rule is Campagnolo. As a general rule, their stuff isn't compatible with anything else. That's not entirely true, and I'm not sure about 8 speed cassettes in particular, but I find it's easier to just steer clear unless you're willing to switch everything over to Campagnolo.


Bottom bracket models Do I need to be concerned with the difference between a:

VP BC73 (https://www.halfords.com/cycling/bike-parts/gears-drivetrain-and-cables/vp-bc73-68-x-122.5-square-taper-cartridge-bottom-bracket-271445.html)

and

VP BC73A (https://www.tredz.co.uk/.VP-Components-VP-Sealed-Bottom-Bracket-Cartridge-Alloy-Cups_118565.htm?sku=452354)

apart from the difference in length of 2.5 mm (120 vs 122.5)?

No, they are basically identical.
neither of them will have fabulous life expectancy.


How to fix a stripped pedal crank The threads on my bike's pedal crank just became fully stripped and the pedal fell off, though the pedal itself is fine. Is there any way I can fix this without fully replacing the pedal crank?

If the crank arm is wide enough it may be drilled and a thread repair insert installed or tapped to a larger size. This is best left to your local bike shop. To buy the tools that you will most likely only use once will exceed the labor fee they will charge. They can also check to make sure the repair can be done safely.