How do sidewinds affect forward speed? If I'm riding at 20mph on the flat with no wind, and then a 10mph wind kicks up, if I'm heading directly into it I'll slow down by X mph, and if I'm heading directly with it (i.e. pure tailwind) I'll speed up by Y mph. (As an aside, are X and Y likely to be the same? From experience I'm assuming not)

If this is on a perfectly circular course, is the effect of the side wind (I should have said 'the angle of the wind') smoothly proportional? I.e. assuming constant power output, when doing a lap and so experiencing each angle of wind for the same amount of time, would my speed show a smooth trend from 20-X mph, through 20mph, to 20+Y mph, and then back again, maybe like a sine wave? Or do side winds mess with the cyclist in a way that pure head and tailwinds don't?

For extra credit, do you know where the wind would be coming from for me to be travelling at my original speed of 20mph?

The answer to your questions is not straighforward, as shown below.

The easiest to answer is your first question: are X and Y the same? No, they are not. This follows from the formula for the air-drag power Pa = ½.rho.Cd.V.(V-Vw)² , where rho is air density, Cd is drag coefficient, A is frontal area, V is forward speed, Vw is wind speed.

Suppose that for a certain power input your speed in the absence of wind is V0.
Now if you keep power constant, we have for a tailwind a forward speed Vt : Vt.(Vt - Vw)² = V0³.
For a headwind we have a forward speed Vh : Vh.(Vh + Vw)² = V0³.

For any V0 and Vw, you can calculate Vt and Vf by solving a cubic equation. It is easy to verify by substitution that for a no-wind speed of 20 mph and a wind speed of 10 mph, the headwind speed becomes 13.95 mph and the tailwind speed 27.16 mph (neglecting rolling resitance). So Y>X.

However, I find it more elucidating to consider a return trip along a road heading straight in the direction of the wind first and returning in a tailwind on the same road. Suppose that the trip without wind takes a time T0. It can be shown that the total time Tw is always larger than T0 and that the ratio Tw/T0 does not depend on A, Cd and rho nor the distance : Tw/T0 = (V0/Vh +V0/Vt)/2.

A few years ago I made a graph where the ratio Tw/T0 is plotted against the wind speed,  assuming a wind-free speed of 20 mph, shown below.

The graph shows that a wind always increases the return time. At 10 mph wind speed the return time increases by 8.5%. At 15 mph wind, the increase is about 20%. This calculation assumes that the rolling resistance is small compared to the aerodynamic resistance, which is roughly the case at 20 mph.

Your question about the effect of a side wind is much more difficult to answer, because the wind-exposed area plays a big role. This takes a much more elaborate study. There is a free-access paper on the internet by Osman Isvan that investigates this question in depth.

See research paper Wind speed, wind yaw and the aerodynamic drag acting on a bicycle and rider


Can I replace QR front wheel with bolt-on? The 27x1 1/4 steel QR front wheel on my 1985 Raleigh Grand Prix has a bend; not just not true, it is bent.  I cannot find a replacement wheel, but have a 27x1 1/4 steel wheel with a bolt-on axel.  Is there any problem or consideration in replacing a quick-release wheel with a bolt-on wheel?
Also, the bent wheel is original; is there any possibility of repairing the smoothly bent rim?

If the threaded axle wheel fits in the dropouts and you can tighten bolts against the dropouts, there is no problem usung it.

If your rim is actually deformed, as in if you loosened all the spokes it would remain significantly untrue, then you will not be able to re-build a wheel with it.


Front derailleur cage on new road bike will not shift I have recently bought a new road bike. On my first ride out, when shifting the the front derailleur onto the big ring the cage would shift over but the chain would not. I took it home and adjusted the height and angle of the cage and tried to remove slack from the cable, I did not touch the limit screws. However this seems to have made the problem worse as I when I shift the front gears the cage doesn't even shift at all.

Not sure if this will help but here are some photos : https://imgur.com/a/1oVjDLX

I've tried looking for answers online and the suggestion is not enough tension in the cables. When I shift onto a higher gear there is little to no slack in the cable but when I shift down there is a lot of slack again after tightening it up, is this normal and could it be the cause?

As others have said front derailleurs are a pain to adjust correctly, so taking you bike to a local repair shop will save you headaches.

However, if you want a shot at getting the front derailleur adjusted properly yourself, stepping through a full adjustment procedure is the way to go.

Park Tool has a great webpage and video that walks you through the entire process.

https://www.parktool.com/blog/repair-help/front-derailleur-adjustment


Lubricating screw/braze-on threads: Bike lube or polylube? Years ago, I made the newbie mistake of forcing a rack screw into a steel braze-on. I had to replace that fork. And I've heard this advice many times: When putting a screw into a braze-on, put a little lube on the screw to keep rust from forming. So I take good care of rack screws and braze-ons now.

I was putting fenders and racks back on a bike today, and I had finished cleaning the screws and eyelets. When I reached into my tool bag for some lube, I realized I had regular bike lube as well as polylube. (That's the goopy stuff you use for seatposts.)

I tried polylube on a pair of 5mm screws and regular lube on a set of 4mm screws. Over time, I'll see which set of threads is cleaner, or if there's any difference at all.

I'm using Parktool Polylube 1000 and Prolink Chainlube (regular lube, not wax).

My question: Is there a difference between using regular bike lube and polylube to lubricate threads? Can polylube be harmful in this context? Or should I be using something else entirely?

Definitely the polylube -- for the same reasons you use it on your seat post.


Is this a crown race? I've bought a headset and I'm not exactly sure what goes where:

Presumably, the thing on the left bottom corner would be crown race, but it's not closed and doesn't really fit snugly to the bottom of the stem (rotates freely), which has 30 mm in diameter (the rest of the stem apart from the bottom has 28.6 mm). Is this how it's supposed to be or am I missing some part?... A photo from the other side:

The other ring in the middle is narrower.

Yes, the piece in the lower left is the crown race. Split types (with the slit) should gently pinch onto the crown race seat of the fork. What's important with that type is that there's zero play (slop or free movement) between the race and the fork. It will be able to turn but shouldn't be able to just spin freely.

If there is play or free spinning, you could go a couple different directions. You could measure carefully (with a caliper) and determine whether the race internal diameter is oversized and/or if the fork's crown race seat is undersized. Then you could get a different one of whichever is causing the problem.

Alternatively, if you just want to make the parts you have work, a good approach here may be finding a shop that has a Stein knurling tool, which is a very fast way of slightly raising the surface of the material, for round parts that are supposed to fit just a little bit snugger than they are.

The other piece is the compression ring, which goes between the upper bearing and the top plate.


What is this plastic part on caliper brakes called? What is this plastic part called and is it possible to get a replacement? It's commonly found on Shimano caliper brakes. I have a pair of brakes where one is missing both of these plastic bits and as a result, the brake makes creaking sounds when operated.

With the information provided by Criggie's comment I was able to find an exploded diagram of the Shimano Exage brake with a part list.

That part is called (descriptively) a "Sleeve". It's part number 83E 0900

Searching for the part number reveals that Shimano uses that same part number on several different brakes.

I asked The Google as nicely as I could but found no replacement sleeves or brake rebuild kits available.
You are looking at:

Making your own per Criggie's comment
Scavenging sleeves from another caliper
Replacing the caliper
Living with the creaking sound
Duct tape?


Are bikes with aggressive positions required to achieve high fitness levels when training on a bike? Are bikes with aggressive positions required to achieve high fitness levels when training on a bike?

My bike fitter claimed that a more aggressive posture is better for transferring power than a more upright position.

Janheine also agreed that a more aggressive position improves power transfer.
https://janheine.wordpress.com/2018/02/12/myth-5-an-upright-position-is-more-comfortable/

If their claims were true, I would need something like a gravel, road, touring, or cyclocross bike to achieve high levels of fitness.

Interestingly, TrainerRoad doesn't seem to agree.
https://blog.trainerroad.com/does-bike-geometry-affect-power-output-we-asked-an-expert/

Assuming proper fit, gearing, and training zones. If I use a city or hybrid bike, would it really keep me from pushing hard enough for fitness gains?

What if I get a hybrid bike fit instead of a road bike fit?

Imagine if Chris Froome trained on a city or Dutch bike. Could he have achieved a high VO2 max of 88.2?

Speed isn't the only benefit of fitness. Getting fit often improves our health and energy levels.

There are reasons for a more upright position such as comfort, the lack of room for an additional bike, visibility, cheaper brakes levers and shifters, more room for accessories on handlebars, better vision, room for a front basket as the handlebar needs to be higher and of the right shape to accommodate it, and even safely allowing high power output downhill. If your less expensive bike is less aggressive, you might prefer to leave it on a trainer.

TL;DNR - The bike you will ride most often is the bike that will get you fittest.

Fitness and power transfer are unrelated. Your bike fitter is presuming you want to make the most of the power you have, so is suggesting an aggressive position is needed.  This is possibly because people who pay for bike fitting tend to also be competitive riders who want to go the fastest they can with the power they have. These customers are already close to peak fitness, so they are scratching for low single digit percentages gains in 'power to the ground' (1% faster over an hour's riding is 30 seconds – that is the difference between winning and not being in the leading peloton).

If, however, your goal is to get fitter, then a more comfortable position is arguably more suitable. The more comfortable you are, the more likely you are to ride more often and further. If the power you produce is the same on a hybrid at 20km/h as on a fitted racer at 30km, and hour of exercise produces the same results in terms of fitness, it's just that one bike lets you go further. If you are uncomfortable and quit riding the fast bike after an hour vs say an hour and five minutes on the hybrid, the hybrid will get you fitter.

As far as 'Bike fitness', training on a hybrid for a century on a racer would be unwise: your training would be sub optimal as a more upright position uses muscles differently, but that is a discussion about specific fitness vs general fitness.

How much difference it makes depends on you – some people find it demoralizing busting a gut to get 20km/h when they know they can do 30km/h on a better bike, and are better off on a faster bike. Others are happy to dial up a work output and accept the speed they get.

No one needs a 7kg $10K bike to get fit, many think they are fit because they can ride a 7kg $10K bike faster than the guy on the 20kg, $200 BSO. The industry loves selling $10k bikes, hence much of the promotional material around the need for a high end racer.


What would cause variable air resistance on a day with no wind? I commute to work regularly. I find that on some days when there's no perceivable wind, I feel like there's almost no air resistance at all and it's so easy to ride at speed. It's also relatively quiet without the wind roaring in my ears.

On other days when there's no perceivable wind, it feels like I'm riding in soup. It's really hard to get any speed up and the air is quite noisy in my ears.

I've discussed with my co workers and they often say they have the same effect on the same days as I've observed. Although they're also travelling in the same direction as me, so I can't rule out a very slight headwind causing the perceived difference.

Possible explanations:

There's a slight tail or head wind on these days.
On days that I'm more rested or energetic I could feel like the ride is relatively effortless.

Are there any other explanations that would contribute? High humidity or a high pressure zones?

TLDR; assuming my calculations below are correct, there's roughly a 10% increase in air resistance between hot, humid days, and cool, dry days. Add in a slight but imperceptible tailwind or headwind, and it's conceivable that you could experience a 4–5mph difference in cruising speed between two days.

Air resistance is the primary force a cyclist must overcome at typical cruising speeds. According to one online calculator, assuming a typical road bike, a relaxed riding position, and a cruising speed of 18mph, 75% of a rider's power is used to overcome drag.

According to your profile, you live in Melbourne, AU, which is essentially at sea level. Using another online calculator, the air density when it's 50˚ and 0% humidity is 1.24kg/m³. When it's 90˚ and 100% humidity, the air density is 1.13kg/m³. So, on a cold and dry day, there's roughly a 10% increase in air resistance when compared to a hot and humid day.

According to the drag equation,

the drag force scales linearly with air pressure. 10% higher density equals 10% higher force necessary to overcome drag. Instantaneous power is determined by the equation

Assuming constant power output, and 75% of that power is dedicated to overcoming air resistance, you end up with roughly a 7% reduction (1 / 1.075) in overall speed. We started with a cruising speed of 18mph, so simplistically your speed on a cold and dry day would wind up being 93% of 18mph, or 16.75mph. I'd say that's enough to notice.

Of course, it seems unlikely that these two days would occur closely together. But if you're comparing a midday ride just before or after a storm to a late evening ride on a dry day a few days before and/or after, it's conceivable that you could wind up somewhere in the ballpark of a 1mph difference.

That said, even a small headwind and tailwind can make a significant difference in your speed. Sheldon's site has graphs showing wind tunnel tests. In particular,

shows that as the wind angle changes from a headwind to a tailwind for a 5mph wind, a rider traveling at a "normalized" speed of 25mph (assuming no wind) would go from roughly 22mph to 28mph. The difference in rider velocity as wind velocity changes seems to be linear, so extrapolating backward, even something like a 2mph headwind vs. tailwind would cause something like a 3mph difference. That's definitely noticeable. Being in a wind tunnel, these tests weren't done with rolling resistance, so 25mph in the wind tunnel is probably equivalent to our earlier assumption of 18mph on outdoor roads.

If you combine the effects, and compare a late evening ride on a dry day with a slight headwind, to a early afternoon ride on a humid day with a slight tailwind, you could conceivably have a difference of 4-5mph between the two days. That's huge.


Shimano dual lever Ultegra ST-6600 The shifter cable broke on the way home from work. The break was inside of the dual lever assembly. I was able to fish out the cable end. But, with a new cable, I am not able to get the shifter to work properly.

Any tips on dis-assembly and re-assembly of Shimano dual levers? Specifically,
ST-6600. I found the techdocs on the Shimano site, but rather obtuse. Tips appreciated.

My tip would be don't disassemble the lever! Shimano unfortunately did not design their shifters to be serviceable.
Shimano STI levers had a terrible habit of fraying the cable at the cable head until it eventually broke off. This was supposed to be remedied in the new generation of shifters but they still do it to a lesser degree. In other words, you're not alone in this problem.
Unless you broke something while fishing the cable head out I'd say there's good chance that there's still a piece of cable floating around inside the shifter somewhere. My suggestion would be to undo the brake cable so you can pull the lever further back and get a powerful flashlight to look around inside the shifter with. Actuate the shifter and see if you see anything amiss. The whole thing would be easier if you take the shifter completely off the bike.


Can I avoid falling in the rain on a corner? I was riding in the rain a few months ago and fell turning a 90° corner. Here are the details:

Riding on a road bike with new 25mm smooth tires inflated to 100 psi (Cannondale Synapse with Continental Gatorskins inflated to 690 kilopascal)
It had been raining for at least an hour, but was not raining hard at the time of the fall
There was no obvious oil or other liquids around, no dirt or other substances
There was no strong wind and the temperature was well above freezing
I was coasting at about 10 mph (16 km/h) around a corner on smooth asphalt
I weigh 210 lbs (95 kg)
I fell to my inside, right side
The fall was immediate with no dramatic skidding or sliding

Here is a photo of the corner, with a red square where I slipped:

I was surprised to discover that the smooth tires are not particularly the culprit in my fall, as bicycle tires for on-road use have no need of any sort of tread features; in fact, the best road tires are perfectly smooth, with no tread at all.

(Edit: Per multiple comments and answers, the above link is not specific to wet surfaces and the assertion that no tread is optimal does not apply here. It appears treads should help with wet surfaces.)

I live in a desert climate so I haven't had much experience with slippery roads, and none since that accident. Is there anything I could have done to avoid falling, or do I simply need to avoid any wet, asphalt surfaces?

16 km/h is so slow that even the worst tyres should keep you up, unless something like oil spills were involved.

If something is so slippy that you fall without warning at such low speeds there is not much one could do. If you have a hunch this might happen tripodding corners or getting off the bike may help.

The first drizzle after a long dry spell can leave a very slippy mix of wet dirt on the tarmac. It sometimes feels almost like soap. More intense rain washes it off quickly.

Some surfaces (eg metal or road markings) can get slippy when wet. Avoid anything that looks smooth and wet. edit: The smooth tar of the patched cracks visible in your photo are also example for such treacherous surfaces.

If temperatures are closer to zero black ice may form spontaneously. It is nearly impossible to distinguish from wet road and is extremely slippy.


What is a good bike-to-lock ratio in price? What is a good ratio, in prices, between your bike and your lock so that it would be reasonable. Say if your bike is 200 GBP, a lock of 20 GBP might be too cheap (or just right!). So where do people draw the line?

Totally depends on the person and how much you're willing to lose. One of the main things you want to do is lock properly -- an expensive lock used poorly isn't very good. And you usually just have to be harder to break than the competition.

For U-locks, you can take out even higher quality ones relatively easy if there is a lot of room left in the lock by either using a jack or having a lot of free space to take out an angle grinder. And you may not want to steal a whole bike -- after a whole bike, going for the wheels or a seatpost+saddle are good options. So, if you bought something like a Kryptonite Evo Mini 5 and used it just for the rear wheel inside the rear triangle to a good bike rack (they'd steal your front wheel and seatpost; nobody's going to saw through the rim), you'd likely be better off than using a New York Lock through just the front wheel (they'd remove the front wheel and steal the rest of the bike), for example. Poor quality cables are easy to remove and same for thin chains (just use bolt cutters).

Your locking scheme should make it difficult for someone to remove the lock. For example, lock your bike to something that can't be easily removed or the bike lifted over it (e.g. a well placed and secured bike rack, not a flimsy sign). Make sure to use good quality locks which are non-trivial to cut. For U-locks, make sure to leave as little space as possible to get a pry bar in. You can use a small U-lock to just catch the rear wheel on a standard diamond frame to the lock and have very little space left and secure the rear wheel and frame. The front wheel can be caught with a cable or another U-lock. Seat can be done with a small pad lock+cable or something, or you can use security skewers. Just putting the U-lock through the frame isn't a great idea since someone can still easily walk away with wheels and seatpost+saddle. See these links from Kryptonite and Sheldon Brown for some more details. You may also want to use a heavy chain in lieu of one of these U-locks, since that requires different tools.

For what its worth, I use a Kryptonite New York Lock Long Shackle and a Fahgettaboutit (which is about 160 dollars of locks) on bikes worth under 300 dollars. But I use them properly, and I park on a college campus where, like most of them, bike theft is a problem (and I can't really afford losing my bikes). I use the good bike racks, and use the Fahgettaboutit to catch the rear wheel and the long shackle to catch the frame and front wheel (or reversed, depending on the rack). This leaves very little space to remove the rear wheel (and a hard lock to break), and makes it too much effort to remove the front wheel. However, if I was in the middle of some random small town or something, I might just be able to get away with a 10 dollar lock on the frame or even just a frame lock. You should be able to get a feel for whats necessary in your area by looking at well locked bikes in the area. And if you can bring your bike into your home, all the better (this means in a place you have complete control; not something like a communal garage where you still need to lock).


Old Soviet Bike - Turist XB3 - What size pedals are these? I have a Turist XB3 1985 turist bike from 1985, made in Soviet Union. What size pedals are these running? I have measured the diameter and it is somewhere around 12.5 - 13mm. Could this be true that it fits 1/2" pedals?

Thank you

While the diameter of pedal axles used on Tourist may be compatible with "usual" ½ inch pedal axles, I would also double check the thread pitch of cranks/pedal threads. Searching through Russian and Ukrainian web pages gives me an impression that the bike has metric thread pitch, when modern pedals are often having thread pitch based in imperial units.

Many people had problems with rethreading the original cranks because they are made of steel, not aluminum, and tend to destroy the tap [2].

I see that some people state that French-made bikes may have compatible pedal thread pitch [1].

http://xt.ht/phpbb/viewtopic.php?f=31&t=35956#p473958
http://xt.ht/phpbb/viewtopic.php?f=31&t=308760#p1649565


Marin MTB eldridge Grade I have a Marin small steel frame MTB circa 1997. Is it possible to upgrade to today's parts such as 10 speed derailleurs and shifters. I'm pretty sure disk brakes are out of the question. If so any suggestions on where to start.

As others have mentioned you'd be cheaper getting a new bike than upgrading.  The frame also  won't support disks,  although if you replaced the fork you could fit a front disk.

Importantly the geometry of a bike has changed quite a lot since those days. I've got a marin pine mountain from around that time and it feels really unstable compared to a modern hardtail and is not corrected for a suspension fork.

However to directly answer your question I think if you replace the entire drivetrain it should work. The rear hub spacing should be 135mm.


Very short travel minimalist suspension fork for rails-to-trails riding I would like to convert a MTB frame to an XC bike for riding on former railroad tracks that have been converted to trails that present a mix of surfaces: fine gravel, dirt road with crushed stone, grass, poorly maintained broken and eroded concrete pavement, and long stretches of well-maintained macadam.
To that end, is there a 27.5" tapered-steerer suspension fork (disc mounts) with very short travel,  perhaps only 25mm-50mm?
A rigid chromoly fork would probably do but I cannot find one that fits the frame without using a tapered-to-straight headtube adapter.
P.S. I'd prefer to avoid carbon, if possible.

It sounds like you don't really need a suspension fork. The surfaces and conditions you describe are what gravel bikes are designed for - those don't have suspension forks, they just rely on larger tire volume and lower pressure (compared to road bikes).
Short travel suspension forks do exist, but if your frame is designed for a longer travel fork the required axle-crown length will very likely be longer than that available on a short travel fork. (Obviously the for longer travel the frame head tube needs to be higher to give the wheel somewhere to go when the fork compresses.)
Short travel forks will also be lower end and therefore lack adjustment and will be heavy.
I'd go with a rigid fork if you can find one the correct length. Of course another option is selling the MTB and buying a (used possibly) gravel bike.


Hard to pedal even on flat street I have a woman's cruiser bike with pedal brakes only. Everything has been working great but when I took a bike ride the other day I was on a flat street and it was extremely difficult to pedal...why and what can I do to fix it?

Start with the easier things before busting out the spanners!

Check the bike over. Low pressure tyres are very hard to ride, so add air with a pump.
Look for anything wrong, that's anything rubbing or otherwise out of line.
Walk the bike around and make sure it coasts okay.
Rotate the pedal crank while lifting the rear wheel off the ground and make sure it looks right with no bad noises/feelings.

If it is the back wheel not spinning freely even when off the ground, sounds like your brake may be the cause.  A teardown can be a complex and messy thing, how's your mechanical skills?

Final point - if there is only one brake and its not working right, don't ride the bike till its fixed.  Many locations require two separate braking subsystems.  Where's your front brake gone ?  Also, riding it in the current state may worsen a repair into a replacement.


Bike pulses while applying the front brake. I'm unsure what the cause is Once per rotation of the front wheel, when braking, the bike pulses under me. The brakes are calliper rim brakes.

Swapping wheels out fixes the problem - so it is definitely wheel related
The wheel is true
I can't see or feel anything different on the brake track.
I have tried cleaning the brake track with degreaser and rubbing alcohol with no luck
I have also sanded the brake track to try to remove anything that could be on there.
I have measured the rim all the way round - exactly 19mm rim width the whole way around.
The pulsing does not occur when the brake goes over the rim joint.

And it's still happening.

Any suggestions?

Measure the rim in a more accurate way for starters. Even 0.1mm can cause a change in the braking power.
Also, with the bike resting on its handles and seat, flipped over, ask someone to lightly hold down the front brake while you slowly turn the wheel and figure out exactly where the trouble spot is and how big it is. If there is no visible difference, and you don't have the means to measure the rim more accurately, then it probably is the width of the rim being uneven. On the other hand if you find that it does not occur at the same spot every time, maybe the problem is elsewhere.
If you can, see if the width of the rim changes radially, fatter near the tire and thinner near the spokes. If the difference in this width isn't constant, it could be causing the problem


Why is my big chainring is so scratched form the inside? I have noticed a lot of scraping on the inside of my Trushift 44T plate. Is it just a function of distance, time and color or is it a clue that something is not working properly? The bike was bought used.

Here is my chainring (bottom) and another from my buddy's bike. Mine did more km so it is not a perfect comparison but still:

Some damage is to be expected caused by upshifts, that said, anecdotally speaking (i.e., based on personal experience), that amount of damage looks excessive.

Speculation

I wonder if the front derailleur was misadjusted so that it could be in the upper position, but not far enough for the chain to properly catch and upshift.  If the derailleur was left in the upper position the chain could partially catch then drop back down to the lower ring.  If ignored and ridden in that position over many, many miles the chain would continual catch and drop, wearing the inner side of the ring.

In terms of upshift functionality, all that really matters is whether the ramps and pins remain functional.  That is hard to assess from the photo (although I see some intact pins).

Next Steps

The best thing to do is make sure that the front derailleur is adjusted properly.  If the upshifts are still acceptable, then don't worry about the damage as it would be largely superficial in this case (i.e., the pins and ramps can still do their job). If you cannot get it to upshift reasonably well then you should look at replacing the affected ring(s).

Finally, with that much wear it is also worth taking a look at the teeth profile the teeth themselves are excessively worn, such that a new chain may skip.  This would be a different problem than the inner surface wear discussed here.

See: Does this chainring need to be replaced?


Was I just sold a used cassette? I just bought this Shimano HG41 cassette and I noticed that not all of the teeth and dips between them look the same. You can easily see this in the image that I included if you compare the teeth on the largest sprocket on the left with those on the right. You will notice that those on the left are wider and the ones on the right are smaller. Also, the dips look like they have different shapes. I am wondering if that is how it is supposed to be, or if there was a manufacturing defect, or if I was sold a used cassette. For reference, I bought the cassette in-person and it came in the box (the box was a bit beat up) and instructions, although there was no plastic wrap over the cassette in the box even though there normally is (although I am not sure if they only do this for higher end cassettes).

In all likelihood, the cassette is new.  The cassette is manufactured this way. The difference in teeth shape and depth is to assist the chain take-up when you change gears.
Look for wear marks on the ramps and grime between the cogs - a new cassette should be clean with no marks.  While it could be possible to clean a used cassette to 'new' condition, (likely more expensive than a new cassette), it would be next to impossible to remove wear marks off the ramps.


How do I get rid of the noise on my Hayes Stroker Trail brakes I recently bought a new bike that came with Hayes Stroker Trail hydraulic brakes.  From day one they were squeeky and not very grippy.  I wrote it off to the burn in period that most disc brakes require.  But after a few hundred miles on them now they are just as bad.  I have bled then in hopes that air in the line was causing the problem.  I got several air bubbles out of the line which helped with the squishiness of the lever, but alas the brakes are still noisy and lack that braking power that I have had with other disk brakes.

I have read a little on this problem and some say that it is just the nature of this brand of brake.  Has anyone found a solution to fixing the squeel, short of buying better brakes.

From your install manual, the "Burnish" period is only 30-40 stops, so you should be beyond that.  If the bike is still within a month or two of purchase, I would suggest taking the bike back to the shop and playing dumb.  They sold you the bike, they should fix the brakes that aren't working properly.  If they say, "they're supposed to do that", I'd suggest checking with another LBS.  The other LBS may even fix them for free (depending on the problem) just to win your business (after you explain what the other shop had said).

If it has been longer than that, you can try a few things to see if it is a minor issue.  I don't use Hayes brakes specifically, but here are some good starter ideas that may work to narrow it down:

Clean the rotor - Easily done with rubbing alcohol.

I use small, single-use, swabs that can usually be found around the diabetic testing equipment at your local pharmacy.  Easy to use and easy to carry with you.
Clean both sides of the rotor.  Inside and out.
I keep cleaning until the swabs come back almost entirely white.

Check the pads for debris - Pull the pads out and look for rocks, plastic, sticks, or anything else that might have gotten embedded in the pads.
Clean the pads - Hit the pads with some sand paper to take off the top layer.
Center the disk in the caliper - This one is in your install/service manual.  So for Hayes Stroker Trail brakes:

Loosen the caliper mounting bolts.
"Squeeze and hold the brake lever.  While holding the brake lever, shake the caliper to position it in its natural centered position over the disc. While squeezing the lever, tighten the mounting bolts." -- Page 2 of the install manual.
This may be different for your braking system (year, features, etc), so check your manual to be sure.

Ensure the disc is mounted properly - Check to ensure that the disc is mounted to the wheels correctly.

From the install manual for Hayes Stroker Trail brakes, the disc bolts should be tightened to 50 in-lbs of torque.
WARNING:  It is very important to ensure the correct torque is used on the disc mounting bolts.  50 in-lbs of torque isn't very much, so save yourself some heart-ache and use a torque wrench.  Remember, brakes are important.

Anything beyond that, and I'd take it down to the LBS, let a trained eye take a look (and listen) to them and see what they say.


Is there a difference between a Shimano 10-speed MTB small chainring between double and triple cranksets? Shimano sells two types of 10-speed chainring, one for 2x and one for 3x systems. The smallest chainring have a 64mm BCD for both systems, and it looks the same to me. So what is the difference between them since they are sold as 2x and 3x specific? Or can they be used interchangeably?

I have a list of 9-12 speed Shimano chainsets here:
https://docs.google.com/spreadsheets/d/1HdcNgmQKFA-lAqQJ3lXQ8SwA4tblAKiOXe9XYJJHYN8/edit#gid=375920416
Refer to the 10-speed MTB tab.
There is considerable overlap between double and triple small chainrings for MTB (none for road).
E.g. SLX FC-M677 is either 38/24 or 36/22, meanwhile SLX FC-M672 is 40/30/22.
Recall that the large ring has aids to pick up from the smaller

but the small ring needs no assistance to have the chain fall off the larger.
So the larger ring matches with a specific smaller
The 10-speed 40-30-22 triple is referred to by Shimano as 'AN', hence a 30t AN means a 30t 10-speed picking up from a 22t. https://si.shimano.com/api/publish/storage/pdf/en/ev/FC-M672/EV-FC-M672-3588.pdf
Since it is confusing to buy the right large/middle ring, Shimano over time would tend to differentiate things that perhaps are not different.
If we look at the M677 double, then it is
https://si.shimano.com/api/publish/storage/pdf/en/ev/FC-M677/EV-FC-M677-3911.pdf

Y1KF22000 Chainring 22T-AA/AC/AY
Y1NA24000 Chainring 24T-AM/AZ
Y1RM98010 Chainring 36T-AY
Y1RM98020 Chainring 38T-AZ

I.e. the 36t is AY picking up from 22t, which could in fact be 'AA', 'AC' or 'AY' (the same identical ring), and likewise 38t AZ is picking up from 24t which could be AM or AZ
Looking at the 22t part number
https://bike.shimano.com/en-AU/product/service-upgradeparts/slx-m670/Y1KF22000.html
it turns out that the identical chainring is used not only on double 10-speed chainsets but also on both double and triple 9-speed chainsets
The 'AA' pattern refers to a 9-speed 44/32/22 triple https://si.shimano.com/api/publish/storage/pdf/en/ev/FC-M970/EV-FC-M970-2592.pdf
And 'AC' appears to be an alternate (to AY) name for a 36/22 double
https://si.shimano.com/pdfs/ev/EV-FC-M3000-B2-4286.pdf
So the answer is that the inner chainrings are the same, and very tolerant of differences, while middle/outer rings are less so. The 2x and 3x checkboxes should be to help with identification - since there are three envelopes:

22t-30t

32t-42t

44t-53t

In this context, '36t' is clearly highly ambiguous, so by saying '2x' or '3x', we can distinguish between a 36t middle ring and a 36t outer ring. This turns out to still be ambiguous in some cases, as there are 36t rings from 24t and 36t from 22t, but it at least helps. The exact part number or two letter code is the way to fully resolve whether it is the correct chainring
However for inner rings (and for 1x drivetrains), these are provably the same part number across a wide range of cranksets, including, in some cases, the same inner chainring used for triple and double cranksets.


Shimano GRX (or similar) and a flat bar - possible? I've got an old MTB hardtail GT Avalanche 1.0. Now it has SRAM X7 (3x10) crankset (but used in 1x10 setup with a nw chainring). This bike is my commuting and "road" bike.

With 36t chainring on the front I can't seem to ride as fast as I hopefully could with a larger one. So the question is: is it possible to install a road (or road-ish - like GRX mentioned in the title) double crankset and a derailleur on this bike? I want to leave flat handlebars in place in order not to make the geometry too strange.

Or, can I somehow use a double derailleur with a 3x crankset? Since I never use granny gear on this bike and don't like 3x mechs.

The GRX is theoretically possible. Or at least better than road ones, bucause it s specifically designed for larger tyres so it gives more clearance for wider chainstays. It moves the chainline by 5 mm outward in comparison to road cranks.

Also, the 46-30T chainrings on FC-RX600-10 give a bit more clearance than compact road chainrings.

Still, your MTB frame's chainstay could be too wide. You will have to measure it or try it somewhere.

As for the flat bars, the Tiagra flat bar shifters SL-4700 should be compatible according to the compatibility chart.


Bike chain too long? Recently, my road bike's chain got cut, so i took it for replacement. A new chain was inserted and the shifting had a good transition. However, when i shift on the harder gears, i hear "crack crack noises" as if the chain is not well fit. I returned it to the repairman who still said he now fixed the problem but i still have the same issues. It seems he only tested the bike while suspended but not on actual ground. Is this because the new chain was too long ?

You probably need a new cassette/freewheel. A new chain on a worn cassette will jump (especially on the harder gears).

The harder gears have two things going against them.
Less points of contact to share the load.
Less points of contact so they tend to be worn the most.

If you have front derailleur then using the bigger ring there will let you use bigger cogs in the rear.  If I can be in 3 or higher in the rear on the big ring up front then I use the big ring up front to keep miles off the smaller cogs in back.


Correct sitting posture for my bicycle I recently bought the below bicycle 26 inch

https://www.trackandtrail.in/cycles/mach-city/ibike-7-speed/

My Height is 5:11,   after riding for one week i started feeling pain at upper back below neck and also near the shoulders,  Can you recommend correct sitting posture for this flat handle cycle.

Also can you recommend few links for good warmup exercise before cycling.

Two items to consider are bicycle fit and riding position.  Here is a link to how the position of the controls can effect neck and back pain http://bikeandbody.blogspot.com/2012/02/have-neck-and-shoulder-pain-on-bike.html  The post discussed positioning of the hoods on a drop bar bike but I am sure you can extrapolate the information to your own circumstances given your flat bar bike.

An additional thing to consider relative to fit is cockpit room... it is not just a matter of handlebar height relative to the seat.  Reach can have a huge impact on comfort particularly with the back and neck.  Too much reach has you stretched out and too little room (short reach) has you hunched over.. both situations force your head/neck into unnatural positions to see the road when riding...   Top tube length is the primary factor effecting reach but considering you already have your bike you can play on the margins by adjusting your seat fore and aft, as mentioned in the comments you can adjust your bar height, or you can get a new stem that can affect both bar height and reach.

With the proper fit, consider riding form.  Your elbows should be slightly bent... that is purposely bent... and your back slightly arched (not hunched).  this position has the effect of pulling your head and shoulders up so you can see the road without having to hold your head back.  It has the added benefit of opening up your breathing pathways.... elbows bent, back arched should be a mantra until it becomes your natural riding position.

Play with your fit.. you may want to consider getting a professional fit especially if you are considering investing in a new stem or bars.  The professional fit will inform you on what would be best considering your current setup.

good luck


What is energy output in Strava application? I'm 115 kg. Today I took two bicycle rides:

42:41 time, 12.1 km distance, 72 m elevation, 17.1 km/h avg. speed, 33.1 km/h max. speed,
50:50 time, 11.7 km distance, 17 m elevation, 13.9 km/h avg. speed, 32.8 km/h max. speed.

Strava calcualted folowing figures about energy in each of these rides:

first: 405 calories / 363 kJ energy output,
second: 353 calories / 317 kJ energy output.

Ever since I remember I was always told, that 1 kcal = 4,1855 kJ. So these numbers are weird or incorrect. What is energy output in Strava or in general?

From Strava's Help page :

  Energy Output

  Energy Output measures the amount of work you've done during a ride,
  expressed in kilojoules (KJ). It is a factor of how much you're
  pedaling, how fast you're pedaling and how much force you're exerting
  on the pedals (measured in W). Power output is most accurately taken
  from a power meter, but if you don't have a power meter we give a
  rough approximation through our power estimator.

This means how much energy was delivered to make the wheels turn. As Daniel R Hicks mentioned, calories in that case mean how much "food" energy your body burned, which will always be higher than the energy you give to the wheels.


Can I use ZZ (steel seal) ball bearing instead of RS (rubber seal)? TLDR: is 16100 ZZ (steel sealed) 10x28x8mm bearing good for 8.5inch wheel at 25km/h under 100kg load?
Long story, in case someone has better solution:
I am in process of replacing my rear-drive e-scooter front wheel because its so atypical I just can't buy tire/tube (weird size split-rim), so I snatched (almost) same size wheel of popular brand. New wheel had weird axle so I used power of hammer to get rid of it and... encountered a blocking bug.
Original wheel bearing: 6000 RS 10x26x8mm
New wheel bearing: 6001 RS 12x28x8mm
I can not reuse old axle, I can't use new axle, I can't find 12x100 bolt-axle (and even if I could, I'd have to drill out +2mm to fork holes).
After learning more about ball bearings that I am comfortable with, I found out that 16100 10x28x8 exists. Perfect match.
However I can obtain only ZZ (steel sealed) locally, RS (rubber sealed) would arrive after a month or two straight from Chinese factory. Ugh.
I know that sealing in bearing is important, and scooter wheel  is much closer to wet and dirty ground than bicycle. It will also spin quite fast as its beefy 25km/h+ scooter.
Me + scooter + baggage can reach 120kg, but speed drops at such load.

The industry term is shield versus the traditional seals. Rubber seals are usually in at least partial contact with the inner race. Bearing shields (as denoted by the ZZ suffix) do not contact either race, so contamination enters more easily than with a seal.
No bicycle manufacturers that I'm aware of spec bearing shields on any bearings. If you put a ZZ bearing in, it would quickly get contaminated, which would accelerate bearing wear.


Maintenance on an Aluminium frame I have an aluminium frame.

The top tube has become slightly scratched or pitted (by something hard, presumably, I don't know what; maybe while it was parked).

Does it need maintenance (e.g. does the paint job need fixing, will it corrode/weaken without), and if so what?

Really deep dents or cracks are a cause for concern, but not little dimples and such.

Also, the "work hardening" of aluminum is considerably less than industry types would make out....I've worked on numbers of aluminum frames that are at least 20 years old with no sign whatever of any structural problems.
Kind of depends what you're doing.  The average roadster isn't subject to much in the way of severe shocks; not so with a mountain bike being used to bounce off boulders and do 10-foot vertical drops.


Upgrading cycle from single to multi-speed I own a  single speed MTB . I'm planning to upgrade it to multi speed. As I'm on a tight budget, should I just upgrade my rear to multi speed or upgrade both front and rear. Is it a good idea to upgrade just the rear to multi speed?
Edit: My front gear set is a single 38 T one. I'm adding the pictures of current front and rear gear set for more clarity.

Some problems in your plan that I can see from the pictures.

There is no rear derailleur hanger provided on the rear dropout. Without it, you cannot install a rear derailleur.

There seems to be no place to install more than one rear cog, as the rear hub is designed to take single speed BMX-styled freewheel.

Without the possibility to have a derailleur and cassette, you might want to have a rear internally geared hub. This means replacing the whole rear wheel. The new hub has to have the same width as the old one.

To install a front shifter and multiple chainrings, you will have to replace the existing crankset and the single chainring it has with another crankset that can take two or three chainrings. Then, these two/three rings should also be bought and installed. None of existing parts can be reused.

It is not clear from the pictures, but most likely to install the front derailleur you will need an adapter on the seat tube. Even with such an adapter, it is not clear if the front derailleur will be in a right place to work.

A narrower chain is often required if a cassette is used.

A method to draw and attach shifting cables along the frame from shifters to derailleurs or the hub has to be devised.

The list of possible modifications is already so long that implementing them while being on a tight budget is impossible. At this stage, selling this bike and getting another (used) one with gears is indeed the cheapest approach.


Edit gps recorded track I'm using Garmin Fit for my phone. On a long ride my phone went out of power and didn't manage to record the last of the track. I've uploaded the first part of the ride to Garmin Connect and can export the ride to gpx.

My question is
Please help me find a online-service that allows me to:

Manually edit and finish my route using an editor with "stick to road" functionality

Set the time for the new points, so I will get an average speed for the last part of the ride and the total time will be correct (I know that one).

Export the result to gpx or another convertable format, to upload to Garmin Connect.

Interesting question. I don't know if there is a better way but I can offer a couple of suggestions.

There's a thread over on BikeRadar where someone is wanting to stitch two FIT files together, there's a suggestion to convert to TCX then manually merge the files using a text editor.

http://training.bikeradar.com/forum/longest-day-road-challenge-324/combining-separate-garmin-files-into-single-ride-152481

The posts within the thread indicate that the suggested method works.

Your case is obviously more complicated since you only have the one FIT file to start with.

So, you can manually create an activity to represent the last chunk of your ride. Garmin Connect supports this, although I don't know how functional it is. I do know that Garmin Connect will allow you to export your activity as a TCX, as I have done this. I can also suggest the site rideWithGPS, which is my preferred portal. RWGPS will allow you to manually create an activity (including drawing the route on a Google map, let you to enter start/total times, and then export it (as TCX History).

You need to register with RWGPS but I don't think you need the pay account to do anything I've suggested.

Whichever way you choose, by the end of this process you should have two TCX files that you can merge.

In passing, GPSies.com is a great site for format-to-format conversions, although in your case you'll get your resulting TCX into Garmin Connect no problem.

One thing I would ask is that you let us know how you get on - I've never needed to do this but I'm a big Garmin user and there may come a day when I'll want to know this myself

Good luck!


Campagnolo 1973 strata cranks(BMX) help I am installing them on a very rare BMX frame.the bottom  bracket shell measures 66mm.I believe I'm looking for a spindle length of approximately 110mm.it also has to have English threads.my question to you campy gurus as what part number am I looking for or combinations of measurements that I can shop for? also any leaves and or ideas on exactly what I'm trying to do.

You are going to struggle a bit with this one unless you can find the correct BB of that vintage, which is a big ask insofar as Campagnolo didn't make a huge number of these cranks to start with and information on them, even at the factory (with whom we are very closely connected) is very thin on the ground.

The biggest problem that you will have is that the square taper used on the inside of the cranks was neither an ISO standard or a JIS, as at the time these standards didn't really exist - all manufacturers, campagnolo included, used proprietory, in-house standards.

The 2 degree taper angle was generall standardised but the starting square size and the length of the taper was not - so it was recognised by mechanics and assemblers at the time that some crank / BB axle cominations were a "go" and some were a "no go" and that the best thing to do to be sure of not only a good taper match, but also, consequently, a good chain line, was to use the crank manufacturer's matching BB set.

If you mismatch, the consequences are generally cracked cranks, either because the area bearing the load is not enough (happens with accurately made ISO cranks on JIS axles) or the crank migrates too far up the tapers so the crank bottoms out on the taper, and in some cases splits as the fixing bolt pushes it hard against the shoulder of the taper which is curved. Much less commonaly and in some ways less seriously - but just as useless - the taper can emerge out through the opening square of the crank so the crank bolt bottoms against the end of the BB axle before it's washer comes into contact with the inside of the crank.

So, if the axle length in your case looks to be around 110, I'd guess it's actually 109 (Campag Pista type, look for BB axle 120-PP-68 and use a 1mm shim under the matching Pista fixed cup) or you could "try" the current Pista BB (which still uses the Campagnolo proprietary tapers) or finally, some of the last generation of "FAG" style BBs, the AC-H and AC-S 111 mm BBs might do the trick. All would need a spacer or two to account for the 66mm BB width.

I've sent a query to our colleagues at the Campagnolo factory with regard to this but I would be surprised if the information can be easily dug out of their archive ...

HTH
Graeme
Velotech Cycling Ltd
Campagnolo Main UK Technical and Service Centre


Shimano Steps E6000 battery charge percentage falls abruptly When the battery charge gets to about 20-25% it drops abruptly to 5-10%. The steeper the hill and higher the load drop percentage is higher.
Examples:
from 25% to 6% steep hill
from 13% to 8% small hill
from 19% to 8% steep hill

All in High assist. Bike is 2 weeks old / 250km ODO

Is this normal?

This is a sign of an unbalanced pack. One of the cells is weak and under load its internal resistance is increasing and voltage decreasing.

Normally this only happens with an old, worn out pack that hasn’t been balanced or has mismatched cells.

If your pack is new, I’d get it replaced ASAP under warranty.


Is it possible to accurately measure airspeed on a bike, and is it useful? So riding into a 15mph headwind at 15mph, your airspeed would presumably show as 30mph. In no wind, airspeed of 15mph.

What would the airspeed be if cycling at 15mph with a 15mph crosswind?

And would viewing airspeed be at all useful to a training cyclist, apart from relatively determining what the wind speed is? The only reason I'm even thinking about it is because so don't have a power meter. :)

There are devices designed for bicycles that measure airspeed. And older example is the iBike, but there are others. The iBike is intended to be used as a stand-alone power meter, and makes assumptions about the drag area and rolling resistance of the bike/rider, then combines those assumptions with speed and gradient information to estimate power.

The other airspeed devices (for example, the Notio Konect) are used in conjunction with an on-bike power meter to determine aerodynamic drag; the on-bike power meter measures power, an on-bike speed sensor measures speed and acceleration, and (sometimes) other sensors will measure gradient and air density. From these measurements, aerodynamic and rolling resistance drag can be estimated. Of the airspeed measurement devices that are currently available as of January 2020, none measure yaw -- they only measure airspeed from directly ahead. There are a few devices that are in development that do measure yaw.

This SE.bikes question and answer describes some of the calculations involved in the estimation. A brief description of how the iBike estimates power is discussed in this SE.bikes topic here.


Just found a vintage Sears & Roebuck 'Ted Williams' Free Spirit 3 wheeler. Can I modernize it? It's been in my girlfriends back yard for years and I'm under the impression that it's a pretty uncommon bike because I can't find any information on it. Her stepfather spray painted a camo pattern on it, changed out the original handle bars and seat for some Mongoose crap, crashed it, then left it to rot. I just decided to make it a project and was wondering if anyone knew the specs on it and if I could use modern 24" BMX parts on it.

The only salvageable parts are the frame, rear axle, and basket frame (basket is MIA), it basically needs a complete rebuild and I thought it would be funny to turn it into a pseudo BMX bike. My biggest concern is finding modern wheels for the rear axel.

I'm sure I'll have plenty more questions as I get into this bike a bit more.

Sure, anything is possible, especially if you have access to a oxy-gas welding or brazing torch (or arc/MIG/TIG welder), a grinder with a cut-off wheel and a willingness to cause mayhem.

As a BMX, it'll be heavy and ungainly, especially around corners. When you pedal, it'll pull to one side as it doesn't have a differential, but it'll be tons of fun and something different.

Why not put a really big wheel on front and turn it into a rocking trike?


Quill stem diameter not matching the fork...possible to get around this? I refurbished my bike and in the process got a new shiny quill stem to replace the original threadless stem. Unfortunately, like a dunce I forgot to ensure that the diameter of the stem adapter (the big bolt that connects the stem with the fork) fits the diameter of the fork. The quill stem adapter is ever so slightly larger in diameter than the fork.

I really want to keep both the brand new stem and the fork. Is there anything I can do to make them fit? Some sort of adapter to fit in between? Maybe a thinner bolt that fits the fork and the quill stem - and then somehow add "filling" between the new bolt and the stem? Open to any ideas.

EDIT

It looks like I'm SOL. But in case this helps, here's the current threadless headset and the new quill stem I'd like to mount on somehow.

There are products that do this, but they rely on the quill fitting inside the steerer.

You can also get threadless clamps that allow you to run a fork with no stem, and effectively DIY that product. They're mostly used by recumbent bikes that have a second pivot holding the handlebars, rather than by people not using handlebars at all.

If you're lucky you might be able to find a different quill stem that will fit inside your steerer tube. But then you have an aluminium steerer being pushed on by a steel quill in a way that the designer never thought about. That's why the commercial product clamps the quill rather than using the wedge bolt it was designed for.

But since the quill won't go into the fork steerer tube, that's never going to work. Milling out the inside the of the steerer tube, even a small amount, is risky. It's one of those "probably ok, but if it's not your face hits the road" things.


Bike feels like it's slipping/shifting gear when pedalling while standing up on max gear not familiar with bike terminology, so sorry if this doesn't come across well. My bike will make a loud clicking noise and the pedals will give some resistance when I pedal whilst standing up. If I sit down it is perfectly fine. Shifting down to lower gears allow me to stand up and pedal with no issues whatsoever. It's hard to see what exactly is going on when the only time I can get the issue to occur is when I'm standing up on the bike.

Hope someone can help me out!

Chain is probably jumping on cassette.

This could be just a stiff chain.  Clean and lube the chain.

If not a stiff chain then more likely a worn chain and or cassette/freewheel. When they are worn they don't match up well and can jump.

If by lower you mean mean the bigger diameter gears they are less likely to jump as they have more teeth touching.

You can get a relative cheap tool to check for chain stretch.  If the chain is stretched then replace it.  Cassette/freewheel is a little harder to measure wear - I bring up a picture of a new one and compare.  Or just buy a new one and compare.  Or just post a picture of it in you question.  If you replace the cassette/freewheel then always replace the chain.  You can get like 2-3 chains per cassette.


Replacing 30 yr old tires; the new ones don't fit I pulled an old touring bike (Ross circa 1980) out of the basement and bought new tires for it. Both the old tires and the new tires are labeled 27 x 1 1/4, but the new tires are larger than the old. They fit into the rim fine, the inner diameter of the tire is correct. But the new outer diameter is greater, and the new tire rubs against the fenders and cannot spin freely. The new tire also seems wider than the old but I didn't measure and am not certain.

My question is, since the inner diameter of the new tire is correct with the 27, would I be able switch to a smaller size to accommodate the fender, or am I stuck with what I have? The new tires I bought are cheapo Bontrager touring tires ( http://bontrager.com/model/08860 ) - if I bought another brand or style in the same size, would that help?

You can find 27x1 1/8 tires pretty readily. You may want to try that smaller size. The height of the tires can vary a bit by the manufacturer.


Zero Offsetting P1 pedals using just Rouvy android mobile app I don't have a bike computer, rather I use my old cellphone for that matter. Does anybody know how to do a zero offset of P1S pedals using Rouvy app? Apparently, there should be an option when you pair your sensor, but on my app I don't have one. Please see the attachment and thanks.

Here is what I was received from Rouvy help desk:

"The problem is that this feature is not available on Android. But, you can use any desktop app and just Zero offset your pedals and then use your phone for a ride."


Cut U-Lock....Bicycle Left? Is this a common thing, and if so, what is the motivation behind it?

When I went to unlock my bicycle this morning, when I touched the U-Lock, it basically fell apart.  It looks like someone used a hacksaw and cut through it.  If it had been half-cut, I might think someone interrupted them (but even that is unlikely since you just need to say, 'I've lost my key!').  But in this case, it was completely cut.  I had a cable around the tires as well, but it was all connected to the U-lock; so it was completely unsecured as soon as they cut the U-lock.

This was in a parking garage with many bicycles.

Do bicycle thieves 'prep' bicycles and then return later to steal them all at once?  I was gone for two weeks, so I have no idea how long it has been cut.  I'm mostly just scratching my head wondering why anyone would do all the work, and then leave the bicycle?

According to campus police reports (apparently backed by video surveillance), an organized gang of bike thieves operates in my area using techniques like this. They use the following system:

A few "spotters" stroll around the campus and pick out the $1500+ bikes.
An hour or so later, a different thief, dressed in coveralls etc. comes by and cuts the locks with appropriate tools. He then walks away, leaving each bike with a cut lock.
An hour or so later, a third group of thieves comes round to collect the bikes. They put away the cut locks exactly like a rider would put away a lock they own, so that it appears to onlookers that they are the owner. They then ride off.

So apparently at least some of the more sophisticated thieves will go to the trouble of separating the cutting from the theft, if they know they are under surveillance.


Commuting: How to carry office clothing so it doesn't get crushed? I have the bike, I have the best route; but now I want to know, how do I transport my clothing in each day? I typically wear suit pants and a business shirt, but not a suit jacket.

Am I better off leaving my clothes at work, or is there a special bag that would let me carry in shirt/pants without them getting crushed?

You have two options, essentially: You can either carry each day's clothing on every trip, or store clothing at work.

Carrying clothing daily

If you're going to do this, you'll need to find a way to roll up your clothing so it's not completely wrinkled. Be aware that even packing clothing in the most wrinkle-free way possible will still not keep it as fresh-looking as when you pull it out of the closet.

Many business travelers have found that the best way to transport clothing is to roll it. Do some searching, not on bike sites, but on business sites, and you'll find videos that get into this in more detail. But the gist: Fold along seams, then roll your clothing. The parts that must be least wrinkled (shirt collar, for example) should remain on the outside. You can also experiment with rolling around a towel, leaving some extra towel at the end and then rolling that around the bundle. This will become your clean-up towel at work.

As you're showering at work (or taking a sink bath), hang your clothing up and let it hang up a bit. Allow a little extra time for this.

It's worth noting at this point that many people continue to sweat even after they stop exercising, so you may want to wait ten to fifteen minutes before showering. (Riding gently for the last mile or three can also help.)

There are special cases that hold clothes, but they all (to my knowledge) involve folding them. I think that this will invariably crease the clothing.

Storing clothing at work

If you have a spare closet or other space where you can leave clothing hanging at work, this is a great option. Consider doing a half-commute on Mondays, carrying the bike and clothing in, then riding home. On Friday, reverse the process.

If you have a space like this, you can also leave shoes there, and possibly even a travel iron for touching up clothes (if you want to look particularly sharp).

You might consider leaving a spare outfit at work in any case. I always worried that I would forget, say, underwear, or a belt, so I left an older set of clothing in my locker.

If your work doesn't have a space like this, look into nearby gyms. Some gyms will let you use the showers and locker room for a small fee, one that's smaller than a gym membership. Some larger businesses even have gyms on-site for employees.

It's worth noting that commutes of a mile or two may not require changing at all, but you'll still have these things to deal with in very hot or cold weather, or when riding in the rain. (Edit: Your 6k commute is a bit long for this, but it's still good advice in general.)

Best of luck on the commute! Speaking from personal experience, I recommend allowing a lot of extra time the first few commutes, and also doing a dry run of the route (if you haven't already). Also consider talking to any cycling co-workers: Some of them may have solved the problems related to your specific workplace.


Single chainring conversion issues I've got a Specialized Crosstrail Elite. I want to get rid of the front derailleur and go for a single front chainring.

Its a 68mm BB shell but needs a 73mm BB with spacers. It currently has a FSA Modular VDrive Crankset, 44/32T. FSA only do a Modular single chainring which is 38T. I'm looking to go larger, minimum of 44T.

I'm looking at changing the crankset to Shimano, including the BB. If I want a bigger chainring, I'll need to go for a road crankset, but because road cranksets run on a 68mm BB I won't get the clearance at the chainstays. The spindle length isn't as long as MTB cranks.

If I go with an MTB crankset, I can't seem to get a chainring over 38T. Which is two small. I'd also need to run a narrow-wide ring to decrease the risk of chain drop.

I'm going around in circles

You are correct that you may run into clearance problems if you just put on a road crank.

You should get a narrow-wide ring no matter what. There's no reason to use anything else for a 1x.

To get the kind of gearing you want (44t and higher on a mountain 1x crank), the main way of doing it from scratch is get a 1x crank arm set and BB of the sort appropriate for your bike with a 110mm direct mount spider available for it. You You can then use any 110mm narrow-wide chainring, which come in the "road" type sizes you want, and some of which are inexpensive to boot.

Currently what's going on is a bunch of companies have 110mm direct mount spiders and/or cranks that can take them, all based on the SRAM 3-bolt standard. Some examples of that are the Origin8 Thruster crank system and Cane Creek eeWings.

Also, as far as your existing cranks, my understanding is the mounting pattern itself is the same between all the FSA modular cranks, and is also shared by Cannondale SI cranks. There are various FSA direct mount rings that fit it in more "road" type sizes. Some of the fancy 3d type ones like the SLKs may have physical incompatibility with your cranks, or not. But, mostly, I believe the distinguishing factor in what Modular type rings in their line up they say will fit it is about guiding people to wind up with a chainline that makes sense for each crank's application.

Anyway, FSA doesn't seem to offer a 110mm direct mount spider for their Modular cranks, which I find kind of odd, but Cannondale does have them and I assume they'd fit without issue, although I haven't actually tried it. If I were going to try going that route, because you'll be in hack territory, what I would do is get the spider first and then take measurements once it's mounted to determine what type of ring offset and/or spacers to use to get the chainline you want, rather than trying to figure that out in the abstract and order everything at the same time. It would be an experiment, but I bet you could get this approach to work without issue.


What trigger shifters would be compatible with my Nexus-8 internal gear hub? I've looked at similar questions to this and the only shifter that is brought up is the Shimano Alfine SL-S503 8-speed shifter. Are there any other compatible shifters (preferably trigger-shifters)?

Shimano internal gear hubs require their own shifters. They are not compatible with derailleur shifters.

According to the 2017-18 line up chart, the SL-S503 trigger or SL-C6000-8 'gripshifters' are your only choices.


How does a crankset removal tool work? I don't have one to examine. How exactly does a crankset removal work?

one such as this.

The crank removal tool has two threaded pieces. The larger threads into the crank (after you've removed the crank-bolt with a wrench).  Tighten it all the way down, as these threads will take all of the force that is required to remove the crank.  The smaller threaded piece screws into the larger.  It has a flat end on it which goes into the crank.  Turn this until this flat end makes contact with the end of the bottom bracket spline (the bit that you removed the crank-bolt from).  Then keep tightening it.  The flat end will push on the spline and pull the crank off--remember that this piece is threaded to another piece that is threaded to the crank itself.

It's an excellent example of a simple machine--the jackscrew. I'm sure that Sheldon Brown has a great description with photos, line drawings, etc... @gcb provides the link.


Shimano 8/9/10 speed freehub conversion to 11 speed does not appear possible due to changed spline pattern After remaining unchanged (with a few exceptions like FH-7801) for nearly 20 years the Shimano freehub body spline mount has changed along with the width.  I had hoped I could refit a 8/9/10 speed rear hub (FH-M756) to work with 11 speed.  But the mounting face on the 11 speed freehub body is totally different compared to the old 8/9/10 design.  I don't see any hope in retrofitting old hubs with new freehub bodies.  Anyone found a solution short of hub / wheel replacement?  The "Zinn" filing down method seems to be the only hack available for standard Shimano brand hubs.

FH-M756 freehub body Y3BD98010 cannot be replaced with FH-6800 body Y3CZ12000 (see photo).

There is no remotely practical way of doing it. It's possible that could change in the future as 11 trickles down more, but probably not likely given that the interface is also different on the standard axle, less expensive 11-speed road hubs they've already made.

Just to be clear though, 11-speed MTB cassettes do not require a new longer freehub, because the large cog overhangs.


What type of rear derailleur to buy? My cheap bike that I use to commute has been taking a lot of punishment (mostly from salt that's been used to melt the snow). I've been thinking about changing the rear derailleur (maybe not right now, but for the summer), but I'm not sure what replacement part to get. My bike has a 6 speed 14-28T cassette.

This is a picture of my derailleur. I think it's a direct mount, so I was thinking about substituting it with the Shimano TX-35 Rear Derailleur Direct Mount.

And this is the replacement part that I'm thinking of buying.

Would the replacement part work, or do I need one with a hanger?

Thank you very much everyone.

The Tourney RD TX-35 should work fine. All Tourney level derailleurs work with 6 and 7 speeds (sprocket spacing is the same). The 35 without the extra hanger tab looks much less cheap in my opinion.

I agree with suggestion made in comments to replace the cassette and chain at the same time.


What should I consider when buying a respirator? I'm using my bicycle to ride from home to work and back. Now I face a problem that the air is not so clean: dust, car exhaust etc.

So I'm thinking of buying a respirator (i.e., an anti-pollution mask) to filter the air I breathe.

But before I buy it I need advice on what should I consider when first choosing one?

update

I've got a respro bandit now and it seems to be what I needed. It really does it's job filtering the air well and doesn't make it too hard to breathe.

You have a few options. One that has been marketed to cyclists has been  the totobo mask which is from what I gather a re-usable N95 mask (although uncertified by any agency) with replaceable filter peices.  It's cheap to try, at only $25 or so.

The Respro is another option.  It seems like a bit more  customizable, and looks like the neoprene would compress the mask against your face a bit better than the totobo, but it's probably really hot in the summer. These run about $60-$75 for a mask.

Here's a forum link which has a bit of a personal comparison from a few cyclists who use these masks in bangalore.
https://groups.google.com/forum/#!msg/bangalore-bikers/w2vgTWlsOH4/3KSlS0jOj0kJ


Replacing suspension with a solid fork I have an older version of this bike:

They have made some changes to the components since I bought my bike but it is more or less the same.  Here are the specs on the newer bike.

I was hoping to put a solid fork on my bike for the winter.  I want to keep the mountain feel and have lots of clearance for wide tires, etc but I want to get rid of the weight and give my fork a rest.

When choosing a solid fork what do I need to know?

Will any solid fork fit onto my bike?  Do forks come in different sizes?  Different diameters?  Different lengths?  I heard something like you need a special fork if you are going to put it on a bike that was designed to be used with shocks.
I know that I want a fork with disk break mounts so this makes the search slightly more difficult.  Ideally I would also like rack/fender mounts.  (For future touring).
My wheel size is 26 inches, what would happen if I used a 700c fork on my bike?  This seller claims thats what he was using this solid fork for.

Edit:

Thanks for the great information.  After reading I have been looking around for a used local fork.  I think that I found one possibility.  But any feed back would be appreciated.

The fork was designed to be used with 700C or 29 inch wheels but it has an axel to crown length of roughly 17 inches (431 mm).  I currently have 100mm Travel in my suspension fork so Lantius says that I should get a fork with a length of 455 mm (17.9 inches).  Is this reasonable?  Does it matter if it was designed for a 700C tire if the fork length is correct?
As you can see in the picture of the fork the fork has some rake.  Is this a problem?  Will that amount of rake make the bike ride strangely/differently?
The steer tube/ headset size is 1 1/8th standard size which is the same as my bike so no concern there.

Here is a picture of the fork:

It sounds like you've sorted out the first issue, headset size.  You'll need something with a  1 1/8" (also seen as 1.125" or 9/8") steerer.

Your bicycle's handling is based on the geometry. Changing the axle-to-crown distance will change the angle of your head tube, altering your bicycle's handling significantly.  The other major characteristic of a fork is "rake", or the distance that the axle is in front of an imaginary line down the center of the steerer.  Within 5-10mm of rake change you should notice a fairly minimal effect on the bike's handling, which is good because suspension fork rake is rarely published and measuring it directly is difficult.

The axle-to-crown distance is one factor, to get that right - assuming your bike has an equivalent fork - you should be looking for a "100mm suspension-corrected" rigid fork.  In practice this means a fork with an axle-crown distance of about 455mm.

If you want a 100mm suspension corrected, 26" wheeled fork with disc brakes that also has rack (I'm assuming you mean midfork low-rider rack mounts) and fender mounts, your options list is relatively limited.  The new Surly Troll Fork is likely to be one of your few options.


The bike shop won't fix my newly bought bike I bought a new bike, a trek MTB marlin 7, and for the first moment (a week later) it started having issues, it was clicking awfully, the pedals broke, the brakes were rubbing, the mudguard broke which I noticed they attached with little plastic things and holes drilled; I got it mostly fixed but clicking didn't go away, I brought the bike around 6 times to the bike shop for them to fix the horrible clicking that came from the back, every time it was a temporary fix, then they said they changed the freewheel and it went away and I thought I finally got a breath, guess what the clicking is coming back, this time creaking too, I don't want to go for seventh time to the bike shop, I just would like to get rid of the bike at this point and have my money back. I honestly don't know if this is normal, this is my first bike, any advice?...

Your new bike doesn't work properly: of course this isn't normal.

At this point, your best option is surely to return the bike to the shop for a full refund and buy a new bike from somewhere else. If there are no other Trek dealerships nearby, buy another brand.

You exact legal rights in this situation will depend on where in the world you are but I would expect that the right to return faulty goods for a full refund should be pretty much universal. One would hope that the shop will just accept your request for a refund. If they don't, you'll need to find out about your rights, and maybe ask on Law Stack Exchange.


Compact crankset interchangeability Have a 2007 Litespeed 10 spd with compact crankset (Shimano R700). The crankarm fixing bolt failed recently with unfortunate results to my backside. Am considering going with Ultegra 6750 compact crankset with Dura-Ace bottom bracket. Does anyone know if this is a compatible upgrade?

Yes, all the 10-speed Shimano 34/50 Hollowtech 2 cranks are more or less drop-in replacements for one another. ("More or less" only because they could be subject to very small differences in where the rings fall, so adjusting the FD may be necessary.) You don't need to change BBs if the old one isn't worn out.


How much leeway do I have on ERD? I am following up on this thread.  I have found a few rims that match the ERD (604) of my rim, and if necessary I can use one of those.  But I would like to consider others as well.  How much leeway do I have in the ERD for my rim?  If I get one with an ERD of 604±X, what's an acceptable X?  Or maybe it's 604+X and 604-Y where X!=Y.  Or maybe I'm overthinking it. :-)  So, in summary... how much leeway do I have?

Unless you measure your spokes and calculate for the hub and ERD, you have no certainty on leeway.
It depends entirely on the spoke length. One build might have spokes just long enough, then a new rim with a 1mm bigger ERD would need new spokes. A different build might have spokes that are just off being too long, then a new rim would need an ERD no smaller than the existing rim.


Is it possible to move my rear derailleur so that it does not touch the chain? My chain is touching part of the rear derailleur. Is it possible to move the derailleur so the chain does not touch it?

This is because the chain is too long. You would shorten the chain to stop it touching the derailleur like this, but you also want to avoid this gear combination of the small chain ring and the small rear cog anyway; it is called cross-chaining and not desirable. In any other gear combination this problem will likely go away because the excess chain length is wrapped around larger cogs.

The only reason not to shorten the chain to the proper length is if it is only just long enough to fit around the big chainring and big rear cog as it is now. This would only come about if incompatible parts had been fitted to the bike, but I would check how slack the chain is (or isn't) in the big-big combo before shortening anything.

If the chain becomes too short there is a much bigger risk of damage by shifting to the wrong gear.


Minimum mountain bike trekking/touring equipment Consider a one week trip in nature, with bikes. Daily routes are to be about 60km with 2000m total elevation change per day (climb, then descend). The group is of 2-5 people. Weather is summer (maybe down to 5 centigrade at night, not sure about rain).

My question is how can we pack smart, so that we can sleep on the trail.

For the bike a multi-tool, tube patches, 1 extra tube, quicklink, pump and chain lube. Anything else?

For food: about 3.5kg of food per rider, or half of that if we pass through mountain huts. Options.

Now, the real question is about sleeping gear. Sleeping bags are bulky and heavy. Here probably the smart move is to get a summer down bag. But what about the sleeping mat? Those are light but very bulky. I am afraid that tying one of the standard foam ones to the backpack will not only create air drag on the descents, but will also catch on vegetation adjacent to the trail. Unfortunately, they are also quite essential.

Any ideas how can we pull this off? How do we carry functional sleeping equipment and still not be too encumbered to ride?

The answer to your question depends heavily on the infrastructure that is available to you, and the highest level of mechanical ability in your party.

As another pointed out, you will want at least two pumps, multi-tools, etc.
  My wife and I do pretty challenging mtb tours with BOB trailers. We generally bring the following (subject to modification depending on how present bike shops might be).

for disk brakes, at least one set of extra brake pads for each type used (e.g. my wife as avid, I have deore xt, so we bring one pair each).  When riding with extra weight, it's shocking how fast brakes can wear away.
two spare spokes for each size used.  These can be taped to your bicycle frames, so they won't affect your packing at all.  Breaking a spoke can end a trip if you don't have a spare.  At least learn the theory of how to do a field repair.  It doesn't have to be perfectly true, but you want to be able to at least roll into a repair.
at least one spare tube of each size in use (you want patches too, but you may need the spare for a big cut).
duct tape. You'd be amazed how this can help you. I've fixed panniers, packs, rain-gear, sleeping bags, and patched a ripped tire.  This can save a trip.  Make a small roll for yourself, you don't have to take a gigantic one.
Consider your water needs.  Water purification can be a life saver.  My wife and I use a steri-pen, which we love.  What you need depends on where you are going. When we rode across Albania, my wife and I brought a ten litre sack of water with us, which may very well have saved our lives on a couple of occasions.  In the alps we just brought 2 litre camel-backs and filled them up at the many opportunities.
bike lights are a good tip and will be useful at camp time.
Unless you are sleeping indoors, you must bring bed rolls.  Depending on the weather you might be able to do without a sleeping bag, but an insulating layer between you and the ground is vital.  I can't stress this enough.  Therma-rest makes small, light and highly packable bedrolls.  Cheap foam rolls are an alternative, and are light but  bulky.  On the plus side however they are virtually indestructible.  You can roll them up and strap them to the outside of your backpack.  At a bare minimum bring enough for your core (neck to thighs).  You'll sleep for crap if you don't bring something to put between you and the ground.
A first aid kit.  REI sells nice, small, packable, reasonably well fitted kits for a reasonable price.  At the very least, bring some bandaids (for blisters), some sunscreen, some painkillers, and some antiseptic.
I highly recommend bringing some kind of emergency contact gear.  If you are somewhere with cell reception, a cell phone is enough.  If not you should consider bringing flares or some such.
Saddle cream.  Unless you are routinely doing that kind of mileage now, you'll be really happy to have this.


What is the difference between SV17 and SV19 bicycle tubes? I know that "SV" is short for "Sclaverand valve" and this page shows a really nice schema for the difference between AV / SV / DV. Especially the diameter of the valve seems to be set by AV / SV /DV.

The diameter of the tube as a whole is set by the notation "28 x 1.40" where "28" means 28 inch (I'm not sure about the 1.40... maybe the inner diameter of the tube".

But then I see "SV17" and "SV18" ... how are they different?

The question is specific about Schwalbe inner tubes as only they seem to use that notation.

SV17 and SV19 are quick identifying codes for Schwalbe tubes. I have reproduced an extract below from Schwalbe's Website. I'm assuming they won't mind for the advertising benefit.

From the table we see that each model of tube they make is given an alphanumeric code starting with AV, DV and SV which you realise are for Auto Valve (Schrader), Dunlop Valve (Woods) and Sclaverand Valve (Presta) respectively, colour coded for easy identifying. Each size of tube is then given a number like 17, 19, so we can look up in the table what tyres it is suitable for. Or more likely, look up what tube best suits our bike and find it on the shelf quickly and easily. Or keep said shelf tidy and organised and re-order from suppliers.

SV17 and SV19 do overlap in some of their size ranges, e.g. they would both fit a 40-622 tyre, but SV19 also covers some 27.5, and 29er sizes and is quite a bit heavier.

The major 'gotcha' to be aware of is that someone (eg an English speaker) wanting a Schrader valve tube should be careful to order an AutoValve (AV) tube not a SclaverandValve (SV) tube, by remembering that Schwalbe is a German brand.


Are deore 9 speed shifters compatible with Alivio & Altus derailleurs? I have a 3x9 hybrid with an Alivo RD and Altus FD. The shifters are Altus. Can I upgrade my shifters to Deore M590 without changing my derailleurs?

I plan on changing my derailleurs in the future but don't want to do it all in one go to spread the cost.

I did look at the 105 flatbar shifters but then I would have to change everything and I don't think there is an upgrade "path" short of buying a new bike

Yes. You can take any 7-9 speed Shimano rear derailleur and use it with any Shimano 7-9 rear shifter. And the Deore front shifter will pair fine with the Altus FD.


Why do e-bikes need dedicated tires? While shopping for new tires on my bike, I saw that some dealers had a specific section for e-bike tires, where the various brands production for e-bikes was present.

Why do e-bikes need dedicated tires?

They don't need them but they are good to have. I have an e-bike that I use as a daily commuter. Here are my thoughts:

E-bikes are heavier than regular bikes and put considerably more power out at the rear wheel (my motor has 350 watts, I add maybe 60-80 watts at most) compared to a regular bike which only has 80 watts alone.
if you have an ebike with a rear hub motor, that’s a considerable amount of unsprung weight at the rear. It’s much harder to hop curbs and potholes with an ebike so it’s getting whacked much harder
E-bikes travel at much higher average speeds than regular commuter bikes. I average 30km/h with peaks of 40km/h which is the electronic assist speed limit. More importantly, I don't make any attempt to conserve inertia as I do with a regular bike, so I stop at all the stop signs and traffic lights. Thus, there's a  lot of braking and acceleration that I do that is hard on the bike and its wheels.
Finally, the rear tire needs to be sturdy as it is getting more wear and also taking bigger hits on bumps at higher speeds than a standard tire.

All in all, I'm still on the original tire which is a regular tire. I'm on the tail end of its lifetime which has only been about 1/3 that of a regular tire. I will replace it either with a beefy "regular" tire or go with one from an e-bike line. I think the actual difference between the two (beefy regular or touring and a e-bike tire) will in reality be minimal.

Update 2018.7: I ended up replacing my rear tire ahead of schedule due to a sidewalk blowout. I’m not actually sure if it was natural wear or if the bike was shivved by a thief. Replaced with a tire from an ebike tire line.

TL;DR: Ebikes require a strong, hard-wearing, high speed, puncture resistant tire. These are also roughly the same requirements as touring tires so some vendors are labeling their touring tires as "ebike ready."


Lowering gears and changing crank length on 1994 Bridgestone MB-5 There are a few things going on here with my relationship to my free barn-find 1994 Bridgestone MB-5... centered around my height and the interplay between my physical capacity and the geography in the areas I ride.

First off: "It's not worth it to dump money in an entry-level obsolete bike." I understand this. I'm here to find out whether the things that I want to change on this bike are possible, not cost-effective... Assume it's a fun hobby for me instead of the easiest solution, please!

Let me introduce both of us: I'm a short-torsoed 5'2". The Bridgestone is an 18.5" frame, which sports a 24-36-46T 175mm Shimano STX crankset with five-leg (arms?) 94mm BCD spiders, and a 12-28T rear (12, 14, 16, 18, 21, 24, 28). (Also Shimano) The rear derailleur is an STX, the front derailleur I replaced, still a Shimano from a different 3x7 mountain bike. Given my measurements, 18.5" is fine. I've swapped out the handlebars and quill so that my short torso is not reaching quite as far. I'm very happy with the bike up front.

Here are my goals...

1) I want 165mm cranks

2) I want this bike geared lower because the steep hills around here kick my ass. My partner has a lower geared (3x7 mountain) bike and after finally riding mine, understands why I struggle a bit. 22T in front and 34T in back would be awesome.

Here are my problems...

3x7 drive train systems seem so obsolete that you are just out of luck unless you want slim pickins. Yes, I've found 7 speed triple cranksets. But... they are either geared at least as high as mine, or they only come with 175mm cranks. I cannot find any 165mm 94mm BCD crank arms, they all seem to be 110mm BCD, or if it's the correct BCD then they are again 175mm. Whole cranksets? there are a few 22t, 165mm out there, but.... for 9 speed.

I'm getting lots of contradicting info from the internet about whether 9 and 7 speed triple cranksets are compatible due to chain width, spacing... I'm a hands-on person, so this internet-research is super frustrating for me.
I did find the Shimano FC-TX801 Tourney TX square crankset with 165mm cranks and a 22-32-42T set, but it's not available anywhere. It's exactly what I want, but that is a moot point, because I can't get it.

Can I use a 9 speed triple crankset? Do I have to buy a 7 speed crankset with the wrong sized gears but right length cranks, then swap out for a granny gear? or would I buy a crankset with the right gears and swap crank arms? What's interchangeable, what's riveted together? (it looks like a lot of the arms are not removable from the whole shebang now)
Advice? Wisdom? pleeeeeaaaaaase?

Not worried about the back, I think I've found simple options for back there.

If I've missed anything or been not clear, I apologize. I hate sitting at a computer, and to boot, my computer is broken and as slow as molassas on a chilly day. I'll be happy to specify or clarify anything....

There are some differences in chainring spacing between crank speed generations. But even within a speed generation, the spacing numbers are not truly standardized. That's one reason for the ambiguity you've found. Another is that with front shifting compatibility considerations on bikes in general, there are a lot of things one can do that fall under the category of setups that can be made to work but possibly with some level of compromised performance. Some voices you're likely encountering would think little of giving all those setups a stamp of approval. Others, such as those of us who do this for a living, tend to operate more in the realm of asking what will perform optimally or as-designed and disregarding everything else, because if we don't we're going to let people down and/or waste a bunch of time.

All that said, dropping in a 9 speed triple crank on a seven speed bike with a 7/8 speed chain and front derailleur is generally fine. So if 165 with a 22t small ring is what you want and you can find it in 9-speed, go for it. If it's another square taper crank, make sure to get a new BB of the correct spindle length unless it happens to use the same as what you've got. I recommend having some .6mm Wheels Mfg chainring spacers to tune things if needed, i.e. enough to put them under both the large and small ring to slightly increase the spacing if you find that your existing shifter and FD are producing too much total throw.

Also, in case it's helpful, 104/64 is the predominant modern MTB triple BCD. The smallest ring size the 64mm can take is 22t. One spendy but not all that difficult way you could go would be getting one of the various fancy interchangeable spider cranks, most of which come in 165 and have or have had 104/64 spiders available.


How do I evaluate the quality of a road bike? I am specifically looking at a Fuji Finest Womans road bike - 51cm.  I am not sure what year it is. The ad description says:

  Women's specific geometry, 51 cm
  Shimano Sora, Ritchey stem, Aheadset,
  pedals with toe cages.  Great shape,
  smooth and easy-riding bike.

The asking price is $350 (Canadian).

I am curious about the quality of Fuji road bikes. How do I evaluate the quality of this road bike -- or any road bike for that matter?

To expand Stephen's answer a little, because there are a couple of really important checks to make. What you're looking for are signs that the bike is being sold because it's not worth fixing:

check the frame and fork for damage. Specifically, if the frame has crash damage it is worthless. Look for slight bends in tubes that should be straight, and for places where the paint has flaked off because a tube is bent. Look at the angle between the front fork and the head tube of the bike, and the gap between the front wheel and down tube. Bikes that have been crashed into something generally bend either the fork or the down tube just behind the head tube. From the picture that bike looks fine.
Look at the braking surfaces on the rims. If there is a wear line on the rim check that, otherwise run your hand along the rim and feel for a curve (across the short side from the brake pads wearing into it), or a break in the rim. New wheels are expensive, so if the rims are too worn it might not be worth buying the bike.
Look at the rest of the bike as Stephen suggests - does everything look ok, do the brakes feel smooth when you test them, is the chain clean, are the tyres in ok condition.
now ride the bike. Does it shift smoothly but definitely? Does it run quietly in every gear? Does it shift under power? Do the brakes work?

Most of the last points are things you can usually fix easily and cheaply. Which means that if the seller has not done them, it could be because the problems are not cheap. Rather than new gear cables and outers, you might be looking at new shift levers (which are not cheap). I would not bother looking at chain wear because even a new chain and cassette are cheap enough that it won't matter, and expecting the seller to throw out a half-worn set just so you can have new ones is wasteful.

Also, if you're not sure it is worth while taking it to a bike shop for a check-over and quote for repairs. Offer to pay them a token amount because you're not getting the work done you just want to know what they think. If the seller doesn't want you to do this before you buy, do it immediately after. That way you can (probably) still go back for a refund.

Please don't be scared off by the list of things that might be horribly wrong. Most of us have bought second hand bikes many times and ridden them a lot. It's that 1% chance that you're getting a lemon that we're talking about, not some mythical horde of dodgy dealers.


Chain not fitting on big chainring I have a problem where my chain is not engaging on the big chainring.
The chain is not touching the FD so, that is ruled out.

Is it possible that my chain is not compatible with my crank?

My chain is a 9 speed Shimano and my crank is an entry-level Shimano 3x crank. This only happens when I shift to the biggest chain ring, it does not happen on the smallest and mid chainring.

The chain and cassette are brand new, while the crankset has had 6 months daily use.

Based on your photo, thats a new chain on an old chainring.

The gap between adjacent rollers in the chain is called the "pitch" and is exactly half an inch for a bicycle chain.

Your chainring's teeth have worn so they're effectively further apart than a half-inch, so the new chain cannot mesh with it for the full length.

The proper answer is to replace the big chainring, but given you've called it entry-level then there's a good chance its rivetted together, not fastened with chainring bolts like a higher-level chainset.    You may be up for a whole new crankset.

The other option is to ride it as-is.  Drawback is that your chain will wear quicker and chainring has fewer teeth in contact, so it will also wear quicker.  Eventually you'll suffer from chain slip, where you stomp on a pedal and the whole thing will spin forward potentially dumping you if not seated.

I'm guessing this is an entry level bike and you've worn out a cassette and chain on your commuting (Great work there btw)  You might be able to pick up a used crankset on ebay/etc for cheap, or consider this a sign that you're now a committed commuter and plan/budget towards the next bike, based on what you know.