Should I adjust rear derailleur as my chain seems too close to each other I am learning to replace chain and freewheel (So far so good). After I put new freewheel and new chain on, the chain are too close to each other at the back now (as you can see in the photo).

I think I need to adjust rear derailleur, is it right? Or maybe the chain wasn't installed correctly ( I cycled around and think chain install seems not too bad).

The chain is too long. Presumably you did not cut it down to size it when you installed it.

All chains are sold with excess length and must be sized to the bike. The length required depends on the length of the chainstays and size of the largest chainring and sprocket.

The easiest way to size the chain is making it the same length as the old chain. You can also find the required length by putting the chain on the bike on the largest chainring and sprocket (and not through the derailleur). This Park Tool video shows how it's done.

Update after getting info that the new chain was cut to length of old chain:

Don't just shorten the chain and see what happens, you need to follow the sizing procedure to make sure the length is right. If the chain is too short for the large chainring/largest sprocket bad things will happen if you attempt to change into that combination.

Before you do that, check that your derailleur has enough total capacity for the chainrings and sprockets you have. Your derailleur looks like a short cage version and may not be able to take up the chain slack necessary.

Total capacity needed is:

(difference in teeth between largest/smallest chainrings) + (difference in teeth between largest/smallest sprockets)

If you have a Shimano derailleur you can look up the specs here. Note there is a link to archive spec docs if you have an older model. If you don't know what model you have or can't figure it out post a pic of the derailleur in your question, and tell us road or MTB and how many cassette sprockets you have and someone will likely identify it for you.


Is it normal that front wheel bends when front disk brakes are applied? When I apply front disk brakes I see slight bend in the rim and wheel. Is this normal or I have a low quality parts.

No, not normal at all. You should have a bike shop look at it for a safety check if you are new to the sport and bike.
One thing that can cause a wheel to bend is poor spoke tension. A good bike shop should be able to fix that for you pretty quickly.


5~10mm rupture (crack) on my tire - should I replace it? This is on my rear tire. I ride about 100 miles a week and the tire has been fine. Will this lead to a blow out?

The tyre wall appears to be splitting or the layers are coming away from each other. Yes, that's bad because it will lead to failure of the tyre. Failure probably isn't imminent but you should replace it as soon as is practical; new tyres aren't very expensive.


Which clothes to use in wet weather for long distances? When I want to do a longer ride (let's say 3 hours) in rainy weather, what are the best ways to keep dry? I already checked this question, but it does not address long rides and most answers only give information about rain coats and tips for short rides, like commuting.

I want to know what clothes to use on long rides:

shoes
legwear
(rain)coats
face/helmet

Short answer: you won't stay dry.  Your best option is to maintain comfortable body temperature.

Longer answer: What to wear depends how cold it is, how hard it's raining, and whether your bike is equipped with fenders.  In the Pacific Northwe't, we have a lot of light rain and a moderate temperature band.  I keep the fenders on year-round (which makes me stick out a lot when I attend events in eastern Oregon ;-) and assume that I'll get wet one way or another.  How I dress depends on the anticipated temperature band:

Above 70 F (21 °C): dress as I would if it were dry, namely wicky polyester jersey & socks, spandex shorts.  These things air out pretty quickly.  I'm usually working hard enough that staying warm is not a problem.
50 - 70 F (10 - 21 °C): A Merino (non-itchy) wool jersey works very well in this band.  It holds water, but it'll keep you warm.  If it's especially windy or approaching the lower temperature range, I'll add a layer, wear wool/poly socks, a beanie, and a polyester light fleece set of tights.  The main purpose of these is to stay warm, especially if I stop (e.g., to change a flat).
Below 50 F (10 °C), it's cool enough that I'll definitely be wearing tights and a rain jacket.  I'll also have the closed-finger gloves.  For my feet, I'll cover the shoes with a neoprene bootie.

Shoes: The neoprene booties don't ward off water as much as you'd think they would, but they do keep my feet warm.  They go on sale for ~$20 at various places.  I've been very tempted to wear sandals and wool socks.

Leg wear - the polyester fleece tights tend to go on sale at Costco for ~$20 in the September timeframe.  They're great for this temperature range.

Rain jacket: I have a nice Showers Pass jacket with lots of zippered vents and pockets.  I find that I tend to keep the underarm zippers open to regulate heat except when it's really cold.  When I get warm enough, I'll roll it up and stuff it in the handlebar bag.

Head beanie: is a polyester, light fleece cap that I picked up at REI (though many other places have them).


Combining flat bar and aerobar: Double stem setup or alternatives? I'm currently running a pair of clip-on aerobars (Syntace C2) on my long distance touring bike. I've set the aerobars up quite high, as for me they are not so much about the aero-part (though it still helps when battling strong headwinds), but mostly about giving my wrists some rest and a change of posture. So far, I really like them.

However, I feel like I could benefit from a bit more reach when riding on the flat bar, so I'm thinking about changing out the stem for a slightly longer one with a bit less rise. This is where the trouble starts, since that would bring the aero's way to far away from the saddle. In fact, they could already benefit from a slightly shorter stem.

Thus it seems like a double stem setup (such as some TD racers use) would solve this problem. 1 short stem up high for the aero's, and 1 long stem for the flats. However, the part of the steerer which sticks out is only 68mm.

Any suggestions for stems with a very low stack height (< 35mm) would be appreciated.
Would it be safe to run a double stem setup with conventional stems (with stack height of, say, 40mm). The lower stem would grab the steerer tube full-on, but the upper stem would stick out for 10mm or more.
Something like this (link) would help a lot, but they seem to be out of production. Does anyone know of an alternative?
Perhaps someone has a different suggestion?

A previous question regard rim and disc brakes had this link....

Essentially use a long steerer tube and mount two handle bars on the bike. Mount disc and rim brakes so you also have brakes on both handle bars (although you could one set of brakes off two levers.)

Edit: (The original Link now broken so I have now linked to a Sheldon page (which still has the the broken link) in hope they restore it.) and attached the pic (although too small to be really useful)


Brake cable prevents handlebars from turning I just got a bike off of Amazon and I'm not sure how well-assembled it is.
I can turn the handlebars about 45 degrees to the left hand side. On the right hand side, I can only turn them about 15 degrees before the brake cable hits the frame and prevents it from turning anymore. I am concerned that this may be a problem if I need to make a sharp right turn.
Is there anything I can do to fix this? Is it just poor construction?
Here are some photos:

When the bike arrived, the adjustment screw for the brake was fully screwed-in, and I loosened it in order to tighten the front brake up a bit (it still feels too loose to be comfortable, though). Tightening the adjustment screw all the way isn't enough to let the handlebars turn to the right.

Sounds like there's not enough slack in the brake cable outer.  Photos will help a lot - you can add them in with [edit]   My assumption is poor assembly.
It is fixable - You can buy more brake cable outer in a kit which should let you re-do the brakes on the bike.  But the bike is brand new and that really shouldn't be necessary.  You might choose to return the bike as "unsuitable" that's up to you.

Aside - we might spot other issues with assembly if you add some clear well-lit photos.  Add one from the right hand side of the bike showing the whole thing, one showing the handlebars area, and if you can a third showing the bike's rear wheel cassette and derailleur.


Does a spinning class fixed wheel bike affect real world form? I just had my first spinning class and hadn't realised it was going to be a fixed gear bike, when the instructor was asking us to get out of the saddle (or half out) the necessary technique felt very unnatural and much more 'bouncy' than what I would do climbing a hill on a road bike.
Does that mean bad things about my real world form or are they just very different things? And if so will a lot of spinning change how I ride?

The exercise bike feels different, because it is fixed in place and can not react to your movements like a real bike.

When you jump out of saddle, your body moves forward in relation to bike. On road, the you keep moving at roughly same speed and the bike slows down momentarily to accommodate the change in relative positions. A fixed exercise bike can't move, so you are moving and stopping instead and that is what you feel as jerking motion. Also, when standing on a real bike you rock the bike to keep your body in place, but since this exercise bike does not allow sideways motion you have to move your weight sideways to put force on pedals.


How practical is an unicycle on uneven surfaces? From my experience riding a bicycle the fact that a bicycle has two wheels makes it rather easy to ride over minor obstacles like minor cracks in the road. Segway also looks promising in this aspect although it's rider's guide is full of "don't do this [usually refers to trying to ride over an obstacle in wrong way] otherwise your Segway looses grip of the terrain and you fall big time" phrases.

Now a unicycle has only one very tiny spot of contact with the road. How does one ride over obstacles on a unicycle?

If the word "practical" ever enters your vocabulary, then you really have no business messing around with unicycles.

Unicycling over rough terrain can definitely be done, but it ain't easy.


How can I repair a tyre with a deep cut? I have some foldable racing tyres, still with plenty of tread but with some small cuts through the tread & cloth.  Can I do anything to them or are they destined for the bin?

You should be able to patch the tire with a tire boot, which you should be able to pick up at your LBS. It's basically a rubber patch that you apply to the inside of the tire, where a gash is. Similar to a tube patch, but thicker. There's all sorts of things that people use for makeshift boots, too, such as a $1 bill. The important thing with a boot is that it prevents the tube from herniating through the gash.

Park Tools Emergency Tire Boot


Why does hunger have a much more drastic effect in cycling than in other endurance activities? When I'm out cycling I know that once I feel hungry, I only have around half an hour to refuel, otherwise I will bonk in a way that all performance is lost and it feels as if the only way to get me home is by pure will. This seems to be a rather common phenomenon since among German speaking riders there is even a name ("Hungerast") for this state. On the other hand I can go out for a 1-hour-plus run at similar intensity while already being hungry without bonking and even am able to push it hard at the one or other uphill during the run. Even if I push this quite far it does not feel as bad as in cycling but only gets more or less an "annoying" feeling that my thoughts start to revolve more around being hungry.

Does anyone have an explanation why this does feel so different in these two activities?

The short answer is that it is purely down to your individual training level and mechanical efficiency in each of these disciplines.

Bonking is a result of fully depleting your glycogen stores.  Once this occurs, your body's only source of fuel to power your exercise is to metabolise fat.  This does not change regardless of what activity you are performing.

However, your state of training and efficiency can impact how long your remaining glycogen stores can last.

As an example, consider the case where an athlete is significantly less trained at running, than cycling.  In this case the perceived effort level may be the same, but in fact, when running, the muscles are generating less power, hence requiring less fuel, and allowing them to last longer before bonking.


Adjust deraillers after changing chain? I just changed the chain on my Cube Acid 2X11sp  mtb. I replaced the old chain with an exactly similar brand, model and length new chain (shimano). Is it NECESSARY to readjust and finetune the speed changing mechanisms (deraillers)?

Replacing a chain on a drivetrain that was previously well tuned will not take it out of alignment. Provided that the new chain is the same width and number of links as the old one and that the cassette and chainring aren't worn, no further work is required.


SLX chainring compatibility I'm considering swapping the inner ring on my SLX double chainset (M665) from 22T to 28T.  I noticed that the newer M675 has a 40/28 option, so I figured that the 28T chainring from this set-up would work well on my slightly older chainset.

However, the Shimano schematic for the M675 chainset suggests that the chainrings aren't backwards compatible with M665.  But I can't see how a flat inside ring with no pick-up points machined into it wouldn't be compatible, providing the bolt patterns match up (which they do, I think).

Have I missed something?

I can't see how a flat inside ring with no pick-up points machined
  into it wouldn't be compatible, providing the bolt patterns match up
  (which they do, I think).

The bolt patterns are compatible.

There are two reasons why the chainrings still may be counted as non-compatible:

Not all Shimano chainsets have identical fitting of the chainring, even if the bolt circle diameter is the same. Sometimes a chainring has to be slightly filed on the internal diameter. I tend to think that this clearly intentional incompatibility is not introduced without a reason and there is some other subtle difference.

In practice: I used some "force-filed" chainrings and do not remember noticing poor shifting.
28T chainring will not be "hyperglide-compatible" with your larger chainring, whatever size it is. The latter is designed especially for upshifting from the 22T. Being shifted up from the (rightly positioned) 22T, the chain links hit the shifting pins and dents so that the chain engages properly. Being upshifted from another chainring, the chain links would not be correctly positioned (except if by luck).

This is the reason why, for example, the Shimano PDF which you linked lists two different 38T chainrings: "38T-AM" and "38T-AK". The former is "hyperglide-compatible" with 24T-AM, the latter with 26T-AK.

In practice: Some people would say that the difference is again not noticeable; here I disagree. IMO the front shifting degrades seriously.


Both brakes don't work well I've had this problem for some time now, both of my disc brakes on my MTB barely work, when i pull the front lever for example i can still push the bike very slowly. They have been properly setup like the tension in the wire and all and the pads seem to have plenty left on them. I have tried cleaning the pads and discs with rubbing alcohol and the problem still remains. Any ideas on what i could do would be appreciated.

Update
So I decided to try and buy new pads and after going up and down a local hill a few times and bedding the breaks in, in a few minutes I managed to be able to do an endo. Still unsure why the other pads behaved as they did as before I installed the new ones I compared the new and old ones and the old ones had pretty much the same amount of compound left on them.

Even if they were heavily contaminated, pads should have enough grip to lock up against hand pressure.

My first guess is that your pads are worn to nothing and you're trying to grip the rotor with the pad holders. New pads would be the first order of the day.

The second thing would be that you've tightened up the slack adjustment too much or that you've clamped the brake line at the brake so high that you have no brake travel left. So you're essentially hitting the limit of the brake when you squeeze, rather than grabbing down with your caliper.

I'd take it to your local bike shop. A one minute look over would tell them if you needed new shoes or brake cable adjustment.

Since replacing your pads resolved it, it looks like either pad contamination (or brake setup) was the problem. To make sure your rotors don't recontaminate your new pads, I'd clean your rotors with some isopropyl alcohol (rubbing alcohol) from your local pharmacy / drug store and make sure not to get anything oily (such as fingerprints) on the rotors.


Tool/proceedure to remove Shimano direct mount rim brake bearings (Ultegra in this case) Looking for some advice on what tool I need/the process to remove the pivot bearings from the Shimano Ultegra direct mount rim brakes. It looks like I'll need a hook wrench(?) to get at the rear silver nuts, but the black notched ring on the front I'm unsure of .
Note this is not a question of how to remove the caliper from the frame - I want to remove the sleeve that the silver bolt sits inside.
Reason for asking is one side feels gritty and a little tight.
EDIT:
I suspect this answers my question: https://si.shimano.com/pdfs/ev/EV-BR-R8010-RS-4254.pdf
The parts I'm referring to are not explicitly listed so I doubt are meant to be serviced.

I would probably leave them alone unless you have a lot of confidence in yourself as a mechanic. Those are the brake posts that are pressed (not threaded) in at the factory, and serve as the brake mounting posts (since the frame doesn't have posts).
If you must disassemble these, you can watch a video of someone with very shaky hands pulling a slightly earlier generation of direct mount brake apart here:
Shimano Direct Mount Rear Brake Repair and Mods Tutorial Guide How To DIY
You'll have to make a couple of tools yourself, and if you're lucky, you won't scratch up the caliper or accidentally break any of the parts. The caliper posts aren't sealed at all, so if this is a chainstay-mounted break, it's likely that a bunch of grit got in there and is making the post/brake body interface gritty.
This newer generation of brake may also be flange-riveted at the back of the brake body, meaning it's a one-way fit; once disassembled, it will not fit back together properly at all.


Worried I damaged my fork fitting crown race I'm an idiot. I've been working on building up a Surly LHT frame and was all going fine until I got to fitting the crown race.

I couldn't get it to fit properly and instead of making a cup of tea and watching some how-to videos like I normally would, I fitted a metal pipe on the crown and a bit of PVC pipe above that and rested the forks on some carpet and smacked the pipe really hard with a metal bar. When I stopped I'd gone through the carpet and put a small (1mm) dent in the bottom of one of the dropouts (not deformed them). After that I went to my LBS and they milled the fork down a bit and fitted the race.

I've inspected the fork really carefully - no visible damage or bending. Is there any chance hitting it that hard could have damaged it somehow? I just don't know enough about steel as a material.

Nobody is going to be able to tell you 100% that its integrity hasn't been compromised from this. Steel can fatigue, brazed dropout joints are strong but not infinitely strong, etc. We all know it's a tough dropout and in all likelihood it's totally fine. But there's always a level of distant hypothetical risk that gets created when things like this happen to bike parts, and nobody can tell you just how distant.

Were a slightly more developed guess to be made, the first steps in getting there would be check dropout alignment (with dropout alignment tools), check the size and parallelism of the dropout slot with a caliper, and ideally check the fork alignment. The detail that's lost in time here, especially from an outside perspective, is exactly how hard it got hit.


How can I keep my feet from falling asleep while riding? I have mountain bike shoes and clipless pedals. When I go on long rides, my feet fall asleep and then very, very painfully wake up (on my most recent long ride, this started happening after 30ish miles and continued for the remaining 45 miles). What can I do to avoid/fix this problem?

I've been suffering from this recently now that I've upped my mileage to 40+ mile rides. My solution was 3 fold:

1) Starting the ride with my shoes quite loose. I have Shimano road / race shoes with 2 velcro straps and a ratchet strap across the top of my foot. I found that I was ratcheting the shoes down too tight.

2) Cleat position. Try experimenting with your cleats in different positions, I've found having my cleats at the rear most setting, allows some of the pressure to be taken off the balls of my feet.

3) Insoles - I've bought some decent insoles as I have quite a high instep, which means all the pressure gets put through the ball of my foot.


How can I find a biking club that has a group for riding with kids in a trailer? How can I find a biking club that has a group for riding with kids in a trailer? I prefer to ride in a group.

Besides talking to individuals in your local bike shops, you can look for 'recreational' or 'touring' clubs. A Google Search for Bicycle Touring Clubs turns up clubs like our club in Utah, Bonneville Cycling Club (formerly the Bonneville Bicycle Touring Club).

Larger recreational or touring clubs will usually rate their group rides by a couple of measures like distance and average speed, and will sometimes classify rides as drop/no drop (meaning that in a 'no drop', the group slows to the speed of the slowest rider).

Pick the slower and shorter rides to begin with, and be prepared to be fully self-supported.  I would welcome riders with a trailer or trail-a-bike on most of my recreational rides, but it can be frustrating if those riders really can't hang with the regulars.

Finally - try to preview the group's route if possible.  Most recreational group rides stick to quieter roads with wide shoulders, but you need to be aware that with the trailer you will be much harder to pass.


What road hubs models or manufacturers use replaceable cartridge/sealed bearings? whilst opinions differ on which is better, cartridge bearings (aka sealed bearings) vs loose-ball bearings. I'm attracted cartridge bearings based hubs, because of the prospect of just periodically replacing these cheap seemingly standard bearings to maintain my hub.

Which manufacturers and/or hub models make make use of standard cartridge bearings? (As opposed to highly custom bearings that could only be bought from the manufacturer)

Maybe approach this the other way around. Identify the wheels you like (one or more model) and as part of your purchase decision, see how easy it is to source replacement bearings.

If there are many and varied places to get the bearings from, not limited to cycling retailers, then you know getting replacements will likely be straightforward. You’ll have done the best you can for now.

6903 RS is a bearing size I’ve seen often enough.

I haven’t got to the heart of the question of course, I also would still be interested if other people know whether there is anything like an industry standard right now.

Update: one resource is a poster produced by Elvedes of the aftermarket bearings they produce.
https://elvedes.nl/wp-content/uploads/2018/07/Elvedes-Poster-v4_web.compressed.pdf
Maybe not exhaustive or guaranteed for the future, but could prove helpful.


What does this warning symbol on my pannier bag mean? I bought a pannier bag which attaches to the rear rack with 3 quick-releases. Each quick-release has a sticker on it:

What does this symbol mean? My guess would be something like "don't hit this with a hammer", but it seems rather unlikely that anyone would, so I'm really not sure what I'm being warned about.

It means "No tools" or "Use your hands."


What would be the "definitive" formula to calculate chainstay length from sprocket size, chainring size and number of chain links? Before I started to write this answer, I thoroughly read this question, its answers and comments:

How do I calculate the diameter of a chainring from the number of teeth?

So, my question tries to ellaborate over this, considering that, for single speeds, there will always be a certain unique chainlength (for a new drivetrain) given the gear sizes and the number of links in the chain. Also, for vertical dropouts, where chainstay length is fixed, there might be a "magical gear" when you have almost zero chain-slack with the right combination of sprocket teeth number, chainring teeth number, and number of chain links.

For that reason, I plan to write some app (html+javascript) to get this length. There is a program which does exactely that, but it is not possible, as far as I know, to know which formula it uses, or if it is actually correct:

http://eehouse.org/fixin/formfmu.php

Then, I think the following assumptions should be made:

The chain perimeter is the sum of the distances between the consecutive centerlines of each pin;
The nominal distance between centerlines, in a new chain, is half an inch, or "exactely" 12.7mm;
The chain is considered to run a straight line between the tangent points where it touches each gear (sprocket or chainring);
The chain is considered a regular polygon sector along the circumference of the gears, as pointed by Lantius in his answer to the linked question.

The result would be the answer to the question: "If I wrap a closed chain with N links around a spocket with S teeth and a chainring with C teeth and pull those apart, what would be the distance between the centerlines of the cog and the chainring?"

EDIT: I'm including an "updated" drawing I generated programmatically (it's quite involving!), so it would be easier to analyze the geometry of the problem:

X is the chainstay length, and it is the hypotenuse of the purple triangle, the short cathetus being R-r (known), and the longer cathetus being equal to B (unknown).

EDIT: (added trig formula) The whole length L of the chain (known) is equal to A+B+C+D. Since B = D, then L = 2B + A + C, or, with all the added trig:

The unknown (B) appears in both sides of the equation, and it looks like it cannot be isolated.

(To make matters worse, there are the natural limitations that teeth profile is not always the same between brands, there might be very small variations of link length between different chains even of the same brand (happens to me quite often), how much chainslack is actually necessary is debatable, and so on, but it would be nice to have a "canonical formula" which actually considers the physical nature of the pinion-and-chain engagement and allows us to calculate this, at least theoretically.)

Thanks for reading!

Unfortunately my crummy draw tool won't let me place the lines very accurately, but this is the idea:

The radii describe right angles to the two chain lines.  I'm pretty sure the two wrap angles on the two sprockets will add to 360 degrees.  The upper quadrilateral has been divided into a rectangle (if my lines were square) and a right triangle.  The hypotenuse of the triangle is the chain stay length.  The short side is the large sprocket radius minus the small sprocket radius.

From the chain stay length and the sprocket radii you can compute the straight chain length and (with a bit of trig) the two wrap angles.  Given a wrap angle and a sprocket radius you can compute the amount of chain on the sprocket.


Is it possible to measure your sit bones at home? Some bike shops have gel pads that you sit on to measure the distance between your sit bones. Is it possible to take this measurement on your own at home, or does this really require special-purpose equipment?

[Related question: Should I use a narrower saddle on a road bike than I would on my hybrid commuter?]

Copied this from a BikeRadar article:

How to measure your own sit bones
Of course the measure you really want is between the centres of your ischial tuberosities – the pointy lower parts of your pelvic bone on either side. Many bike dealers have a pad that you can sit on to measure this distance, but you can do it at home too.
Take a piece of aluminium kitchen foil and place it on a carpeted stair. Sit on the foil, lean forward a bit to approximate your riding position, then lift your feet. This should leave a good impression of your rear in the foil, and you can measure between the two points of deepest impression to get your sit bone width.
‘Narrow’ sit bone width would be 100mm or less, medium 100-130mm, wide over 130mm.
A saddle’s width is measured from edge to edge across the top, and Specialized recommends a 130mm saddle width for narrow, 143mm for medium and 155mm for wide. These ﬁgures should translate approximately across other ranges, with all other factors taken into account.


When does the pace bike leave in Keirin? I understand the pace bike gets the pack up to speed, but of the 8 lap race how do they decide which lap to bring the pace bike off?

Is it based on speed?

The UCI regulations specify not a distance to be traveled but rather the distance remaining: no matter the length of the track, the pacer pulls off between 600 and 700 meters before the finish line. Thus, if the track is 250 meters long the pacer pulls off about 2.5 laps before the finish; if the track is 333 meters long the pacer pulls off 2 laps before the finish; and if the track is 400 meters long the pacer pulls off 1.5 laps before the finish.

(R. Chung posted this comment in 2012, but has not returned to make it into an answer.)


Bottom bracket square taper (cartridge) extraction, too tight in one side I'm getting weird noises coming from the bottom bracket (BB from now on), and I wanted to extract it to check if the problem is there or not.

The guide video I used is no longer public (free) as when I saw it the first time.

I've been successful extracting on another bike, but on this one, I have two issues:

On the right side (drive side), made of metal, the extraction key
doesn't fit! the key seems to be about 2mm wider than the
circumference of the side, as seen on the picture below. I assume
something distorted this side, this bike fell once, but I doubt this
was damaged by that.
The left side is made of plastic, and my hope was (because of the
issue on the right side), to unscrew this side first, but it is very
tight and I am fearful of it breaking if I apply more strength. By
the way, the key fits perfectly on this side.

I've done this before on another BB and it came out just fine.

A picture to illustrate this:

Finally the question(s):

Is there a different technique to extract this BB?

Is there hope in salvaging this BB? it may not be the part making the noise.

Any guess on why the right side is tighter?

I think you'll find that they are actually a different size.  I'm struggling to find any information about it online but I can show you a picture of a tool that should deal with it.  It's hard to say what the difference in size is but there is an obvious difference in thickness of the ends.  You probably just need to find the other size tool and take out the metal end first.


Inner tube valve cut from stretched rim tape? I was trying to fix my sisters flat tire to make some money by charging her fees cheaper than the bike shop.

I found the leak to be on the actual valve piece. Near the base there is a small cut looking to have generated from wear and tear. Looking at the bike wheel rim it came from the rim tape was stretched into an oval around the hole, with one side of the metal hole exposed to rub against the inner tube valve (presumably what caused the cut).

Only parts of the rim tape were stuck to the rim so I assumed it was meant to move and completely ran a finger beneath it all the way around... On the opposite side of the rim tape next to the whole where the valve piece is threaded through is a fold where the rubber rim strip has gathered around that side of the hole as it stretched.

I tried putting some tape around the cut on the inner tubes valve stem as a quick fix, but overnight the tube deflated somewhat.
Instead of just replacing the inner tube (I assume this would only work for a while given the issue has not been addressed) I was wondering what would be the best fix?

Bearing in mind she will probably only pay me $10.

Several fixes

If you have tools, smooth off the cut edge of the hole where the butyl rubber tube touchs it.  A tiny file, or careful use of sandpaper to take the sharp edge off would help.
Reinforce the rim tape with paper masking tape.  Two layers around the whole rim would reinforce the existing tape, with overlap 100mm either side of the valve hole.  As long as the tape sits in the well/valley and has no way to interfere with the tyre's bead/hooks then its okay.   To get the valve through, cut three slots across the hole making an asterisk pattern, and leave the flaps there to fold into the hole around the valve stem
Note, patching a tube hear the valve stem is challenging.  Consider buffing the area of the hole really well, and allow the vulcanising fluid to set for 10 minutes before applying the patch, with pressure.   If the tube doesn't test okay, then just replace it.   Tubes are consumables too.

The best fix is new rim tape, which is not expensive, and the newer sorts don't stretch much around the valve hole.  You might still need a new tube.


Five flats in 4 months on new Giant Contend3 (XL)? All my life I have bought used speed bikes.  I finally sprung for a new bike which I use to commute to work (6 miles each way).  It's a Giant Contend3 (XL).

I keep getting "pinch flats".

The bike store experts tell me it's because I'm not pumping enough air into my tires.  I have a pump.  I am now pumping twice a week.  (It is baffling to me that skipping pumping for a week would result in a flat, as I have always just pumped my tires once in the spring and left it at that).

I got another flat yesterday, despite my regular pumping.

I'm ready to write off the new bike and go buy another used bike.

Is there something else I should be considering?

In response to the comments below, I weigh 220 lb (100kg) and I target 100 psi (6.9 bar) on the gauge.

For road bike tyres you need a pressure gauge -- pumped up so they feel hard to the touch, the tyres could well be at their lower pressure limit. You say it's an XL frame; guessing that you're normally proportioned that could be a fair bit of weight on the back in particular (I'm at the big end for XL bikes, so I don't mean anything negative).  That makes it more important to pump the tyres up properly than for a lighter rider (the ideal pressure is higher and therefore air is lost faster).  It also makes it more important to look after the bike over potholes etc., by standing up on the pedals if you can't avoid the hit.

That bike ships with 25mm tyres. Running just a touch bigger (28mm) can make a big difference to how long the tyres hold pressure (as can thicker tubes or butyl instead of latex).  Depending on the rim width you might win in other ways on a bigger tyre too (absorbing shocks). What width tyres did your old bikes have? If not all of your punctures are pinch flats, tougher tyres would be worth it too.


Bike chain "skipping", but only when not continuously pedaling So I put together a bike a couple months ago. New chain, new chainrings (3 speeds), and new rear cassette (8 speeds). Used front and rear derailleurs from a bike co-op. The free wheel is old but seems to be working fine. All components are Shimano.

It had been plugging along just fine until recently. Now any time I stop pedaling, such as at a stop light or a bump, when I start again, the chain "skips" or "jumps". I'm not trying to change gears, it just feels like the chain is disengaging and then reengaging. It's infuriating and I think pretty dangerous.

When I'm pedaling continuously on a trail, no problem. When I'm standing up on my pedals going up a hill in 2 (front)/7 (rear), no problem. This info, combined with the fact that the entire drive train has to have less than 500 miles on it, and the fact that I went into another bike coop and the tech there measured my chain for wear and found that it wasn't worn makes me think this is not a worn drive train problem.

My guess is that the rear derailleur is properly keeping cable tension when I stop pedaling, which is somehow (?) causing my issue.

Any help is greatly appreciated, it's really my only form of transportation and it's getting to the point where it's unrideable.

Posting this to help others who may stumble upon this.

Took my bike into a local coop, armed with my roommate's hunch about the freehub body, and I removed it, and the guys there said that it had too much play and wasn't ratcheting correctly. Either damage to the pawls or gunk.

Put a new freehub on, and it's as good as new. The take away here for me was: if you're able to stand up on your pedals while going up hill no problem, and your chain only feels like it's skipping after the freehub disengages (coasting) and then reengages (starting pedaling again), it's probably not the chain or cassette/chainrings.

I think this is a weird problem since I had brand new gears and chain, but a very old freehub, which I doubt happens too often, but this worked for me, for what it's worth


Can I use an inner tube that's too narrow for the tyre? I recently got a puncture and when I went to replace the inner tube I discovered that I'd bought the wrong size tube. My tyre is 700 x 40c, the tube is 700 x 28-35c.

What is likely to happen if I use this tube? Will the tube explode when I attempt to inflate it?

In my experience smaller ones go in fine and last as per normal (not that I have pushed this to extremes with a 700x20 in a 700x40 but I only have 26x1.5 MTB tubes and they work fine in 26x2.00 tyres).

Allegedly putting a smaller tube in the tyre becomes a problem if and when you repair it, the patch doesn't necessarily stretch with the inner tube and it can come off.


touring weight distribution I have a cross bike with two back ortliebs,

a 6 liter top tube bag
https://www.rei.com/product/877045/revelate-designs-tangle-bike-frame-bag-large

 Frame bag (the long one below toptube)

and a front pouch
https://www.rei.com/product/117049/revelate-designs-egress-pocket-handlebar-bag

 Front pouch

Do you think I'm better off putting heavy things like tools in the top tube bag/front pouch, and putting light stuff in the ortliebs or vice versa, or a mix of both?   I want to optmize for good handling.  In the past when I have just gone with the ortliebs it works ok but I would love to spread the load out.

General Principles. If you have too much weight in back, the front wheel's contact on steep uphills can be a little bit light, and your odds of pinch-flatting the rear tire can increase (especially if you are running skinnier tires relative to the load), or breaking spokes, because it already carries more of your body weight than the front. If you put too much up front, low-speed maneuvering can get a little more tricky because the handlebars have so much mass/inertia, and also it will alter the handing even at other speeds in a way that may take some getting used to. For typical riding, I doubt it is going to make much difference unless the load is really uneven. Maybe 70/30 or 60/40 weight bias towards the rear is what I've done.

Ease of Access Also A Consideration. I've found it to be more important to arrange things primarily by ease of access, with weight balance the secondary consideration.  Gear that you use only at camp goes in my front duffel or at the bottom of the panniers or seat bag. I end up using my tangle bag as a buffer space for food, an extra layer, paper maps, or whatever other stuff I need to access frequently while riding. Top of panniers for occasionally-during-the-day-access items.


Campagnolo drivetrain compatibility and noise My bike has 2009 Campagnolo Veloce 10 speed drivetrain. I recently changed the cassette (still Veloce 10 speed) and chain (campagnolo Record 10 speed). I assumed the fact that the chain was in the Record series wouldn't matter since it's still 10 speed.

However, I can't get the new setup to shift well. If I tune it so that it downshifts smoothly, it's noisy while pedaling (unless I exert a small force on the upshift lever). If I tune it so there's no noise while riding, it won't downshift properly.

Further reading of the Record chain says it's "Ultra narrow" so I'm wondering if that chain isn't compatible with the rest of the Veloce drivetrain.

Is my issue adjustment or compatibility?

I ended up taking my bike to Dickie at Waverley Cycles. I had a couple of problems:

The chain was too long (I hadn't removed enough links)
The cable adjuster on the derailleur had stripped threads so had movement

He shortened the chain, screwed the adjuster further in and used the adjusters on the cable stops near the front of the bike to tune it and everything is now silky smooth


Using Direct Mount brakes on braze on frame I've just purchased a frame with a single hole in the middle (of the forks and on the rear bit where the rear brakes mount), and a pair of direct mount rim brakes.
I was wondering if there was some sort of adapter that I could buy from Shimano / elsewhere to make it work?

I don't believe there is one. I found one image on Google that appears to look like it would adapt a standard frame/fork to take direct mount brakes, but I wasn't able to find a link to any manufacturer. There is an exceedingly brief discussion in this forum post.
Because direct mount rim brakes are a niche item, I wouldn't hold out much hope for an adaptor. In fact, the link is mainly sarcastic commentary.


Determine which cage length on Shimano Ultegra 6800 How can I determine which cage length is on my road bike? I have a Shimano Ultegra 6800 groupset, with 11-28 casette and 52-36 chainrings.
I found this resource, however, I measure 60 mm between the jockey wheels...
https://www.mantel.com/blog/en/derailleur-capacity-maximum-techcenter/
I also checked the Shimano website, but with no success.

Road rear derailleurs tend to have two available lengths, while MTBs have three. The page you linked to seems to be MTB focused.

See this Shimano page that shows both the SS and GS side by side, it should be easy to tell which of the two you have.


What are/were the differences between the various Shimano square taper cartridge bottom brackets? There have been a number of different square taper bottom brackets by shimano in the last decades. BB-UN91, BB-UN72, BB-UN55, BB-UN26 among many others.
They often correspond to the different tiers of Shimano products (XT, Deore, Ultegra, Dura-Ace etc.).
But how did they actually differ on the inside? On the outside you can see that some used nylon cups while others used aluminium ones. Apart from that it's difficult to get information on the actual differences in their construction and design. What sizes were the ball bearings? What kind of seals were used? Did they all use the shell as the outer race, in order to use lager ball bearings as in the case of the famous BB-UN55? Which surfaces were hardened? Which parts got special weight reduction treatments (cutouts or alloy instead of steel)? What were the impacts of those measures on the longevity of the bb?

From semi-contemporary notes at the (seemingly inactive and archived) bikepro.com site: (circa 1996?)
"In 1992, Shimano released their sealed bearing cartridge bottom brackets for use with their road and mountain bike parts groups, this is the "UN" series of bottom brackets. The three, and the added Dura-Ace 7410 model, have some variations in their appearance and weights. The quality differences in terms of materials used, tolerances manufactured to or bearings used are less discernible.
We called Shimano headquarters in Irvine, California to ask how they differ. Robert explained that the more expensive models are made of better steel and bearings."
Further info was apparently unavailable.
The site also describes their findings from tearing down some of the BBs:
Regarding bearings:
"The UN-50, when you removed the outer rubberized seals around an aluminum washer, revealed seven approximately 4.5mm diameter steel balls in a plastic retainer. With both outer seals removed, you can look straight through the B/B unit. These outer plastic seals, and their integrity, ... are all that keeps the outer world shielded from the inner 7 steel balls. The UN-51, UN-71, UN-91 ... B/B all outwardly appear to have the same bearings as the UN-50 we tore apart for inspection."
Regarding other differences:
"The UN-51 is the successor to the UN-50 and least expensive of the UN bottom brackets. One obvious improvement Shimano made to the UN-51 was to upgrade the left bearing cup from a grey plastic part, which stripped and cracked, to a stamped and machined steel part. The central core of the "sealed" unit, which retains the bearings, is made of fairly sturdy steel. The exterior of this central core is smoothly turned, with the right side bearing cup pressed permanently onto the right side of the core. The right cup is made of machined steel that is colored Silver.
The spindle on the UN-51 appears to be made of cast Black steel that is turned on a lathe to perfect the outer dimension. It is solid, with the ends bored and tapped for the crank bolts to screw in. The left bearing cup is made of Silver colored steel, ..."
"The UN-71 is the successor to the UN-70, and is the specified Shimano sealed unit B/B for use with the Ultegra Road group and the Deore XT Mountain group. The core is made of steel with the area between the cups turned on a lathe to reduce the diameter and thereby the weight of the unit. The right bearing cup is made of Black colored aluminum and pressed permanently onto the right side of the unit's central core.
The spindle is made of hollow Silver colored steel, (appears to be the same one used in the UN-91), with the ends drilled and tapped for the crank bolts. The left bearing cup is made of aluminum,..."
"The UN-91 is the successor to the UN-90 and made specifically for the XTR and Dura-Ace crankset, because the B/B's shorter spindle length and of how deeply the arms recess over the spindle toward the bottom bracket shell. Shimano suggests that combinations other than these cranks are not possible for this B/B. The center core of the UN-91 is made of steel. Between the bearing cups, the core is turned on a lathe to reduce the diameter, and the weight of the unit. The right bearing cup is made of Silver anodized aluminum and pressed permanently onto the right side of the center core.
The spindle is hollow, made of a silver colored steel, like the UN-71, with the ends tapped for the crank bolt threads. The spindle appears to be cast because of the appearance of it's 2 degree tapered sides, and is then machined after to perfect the surfaces. The left bearing cup is made of machined aluminum... "


Are dimpled chainstays weaker than smooth ones, other things equal? Here are two frames: Velo Orange Campeur and New Albion Drake. Assume that they are made of essentially the same steel, 4130 CrMo. The Drake has a very pronounced dimple on the inside, to help increase tire clearance. The Campeur, as far as I can tell, has no such dimple, so let's assume that the Campeur chainstay is entirely dimple-free, inside or out. Other things equal, would this difference make the Drake a weaker frame?

The dimpled chainstay may have less stiffness in certain directions at that point, but if forces are not concentrated there, or in the direction of less stiffness it just doesn't matter.

A u-shaped beam (which is what the heavily dimpled tube essentially is) has less resistance to twisting forces than a tube, but there isn't any significant twisting forces on the stays.


Why are 36-spoke wheels a touring thing? I've been looking at tourers recently and they tend to have 36 spoke wheels (as does my hybrid on the back after I broke my original rim). What I don't understand is why high spoke counts aren't used on more bikes.  Race-style road bikes with low spoke counts and smooth roads I understand. Maybe 26" wheels are tougher than 700C (I don't know). But CX bikes run (sometimes much) rougher surfaces on 700C and similar tyre widths to tourers -- without luggage but surely it's shock load that breaks spokes.  Or 29er hardtails -- rougher conditions still, and it's not like you can expect good technique from all riders all the time.

Summing up comments into an answer, including a few points of my own:

More spokes are stronger; more holes in the rim weaken it. So a sweet spot must be found.

Standard numbers are good, for hole count and spoke gauge

Tourers have to keep going a long way from support, so durability counts (see also brakes); a little extra weight on a laden bike makes little difference unlike in a race.

One broken  or loose spoke in 36 doesn't make the wheel go as far out of true  as one in 32. I'd already experienced this on my hybrid; on the tourer I broke 2 rear drive side outer spokes (damaged in an incident with the chain) and still got home with a nearly true wheel.

Although materials have improved, touring is a conservative discipline in which there's no imperative to change what works.

Touring can mean sitting and spinning over rough roads for hours on end with a lot of weight on the frame.  In CX most of the weight is above the suspension formed by the rider's legs and the rider can stand as required.


Something sounds loose but can't see what I have a relatively new Boardman Pro 29er. It has around 500 miles on it.

I'm having a sound issue at the minute where at certain speeds a very loud resonating vibration type sound starts. I'm convinced it's coming from the crank or bottom bracket but can't be sure. It almost sounds like a loose guitar string.

It seems to be related to cadence more than actual moving speed. I'd say roughly 60rpm.

I've inspected my bike with my fingers for loose nuts and bolts, cable ends rubbing, cables rattling and I can find nothing.

What could it be?

One possibility is that a bolt through the bottom bracket shell is too long and is touching the spindle of your crankset. As the crank spindle rotates, it sets this bolt into vibration, and the frame along with it, at certain speeds.

Check to see if you have a cable guide at the bottom of your bike. If you do, see if the bolt that attaches it to the frame is long enough to reach inside the bottom bracket shell.

Some other diagnostic things you could do:

Remove the chain and coast down a hill, pedaling at different speeds. Does it persist? If not, focus on the chain.

If you have one available, swap the rear wheel. If this cures it, focus on the wheel and cogset.

Take off one brake rotor. Pedal at various intensities somewhere safe. Sometimes various conditions will cause a subtly dragging rotor to start vibrating. Put it back on and try the other.

If none of that is to blame, I would concentrate on the bottom bracket bearings and the crankset/chainrings. Take them all off, clean, inspect, regrease, tighten to specs.


How to replace downtube shifters with stem shifters? My bicycle has clamped downtube shifters that I would like to replace with stem shifters. Is it as straightforward as replacing the downtube shifters with cable stops, then running cable to the stem shifters?

The bottom cable stops in the frame of my bike are on opposite sides. But I've only seen double cable stops like this one where the stops are closer together. Can the cables partially "wrap" around the tube? Are there double cable stops with the stops on opposite sides? Or should I use two single stops on opposite sides? Or should I use a double cable stop at the bottom too instead of the frame stops?

Any advice would be great. Thanks!

You'll need longer cables in order to bridge the distance between where your original downtube shifters were and the stem (where the new shifters will be mounted). And you'll need to install a shifter cable housing going from your new cable stops (on the downtube where the original downtube shifters were located) to the new shifters on the stem.

If you plan on using shifters on the stem without an integrated cable stop you will have to add one just before the shifter(s) on the stem. Most likely your stem mounted shifters will have integrated cable stops though (such as can be seen in the following image)

Make sure to cut the cable housing to the appropriate length, make sure the liner is not folded over on itself before inserting the shifter cable. Use housing end caps on the cable housing if your cable stops allow for it (if there is enough room for the cable end caps). End caps:

It's alright if the shifter cables running from your bottom bracket towards the top of the down tube "'wrap' around the tube a bit" as long as they are not rubbing against the frame or if they are only slightly rubbing against the frame it shouldn't cause issues (it will be even less of a problem on non-indexed friction type shifters). If you find that your cables are rubbing too much on the frame/are not running smoothly because of it your suggestion of using a second cable stop on the bottom of the downtube might not be so bad. Do keep in mind that after the first cable stop your cable is already sheeted by cable housing so in this scenario I would suggest using only 1 cable stop (near the BB on the downtube) and letting the shifter cable+housing combo run all the way to your stem mounted shifters. This will most likely save you money on parts (less cable stops and brake cable housing is not that expensive especially when bought in bulk (10+m)). also this approach eliminates the posibility of the shifter cables rubbing against the downtube.

To neatly manage the cable housing in said situation I suggest using a cable clamp such as this one (dura-ace):

Mounted on a bike it looks like this:

There are also downtube mounted cable stops (clamp style) available where the two cables stops are further apart, which may match your current bike frame's cable stop spacing better. Here is an example:

They appear to be less common though so you might have a hard time getting your hands on one.

Perhaps you could use 'braze on downtube cable stops' . If the bolts used in your current clamp on down-tube shifters (to keep the shifter handles bolted onto the 'clamp body' have the same dimensions (same thread/diameter) as the bolts used to bolt on downtube shifters to a bicycle frame with braze-on downtube shifter mounts you might be able to install these 'braze on downtube cable stops' on your original clamp on shifters to create the needed cable stop.

What braze-on downtube shifter mounts look like:

What braze-on downtube cable stops look like:


QR Rockshox Reba fork for Axle frame? I just found a Reba for a bargain price and everything fits my frame except for the fact it uses quick release rather than axle; the rear dropouts are axle and with this fork the front will be QR, while I am up to changing my wheels because that was part of the plan, I wonder if it's a reasonable idea to mix QR and Axle, or if I should wait to find another bargain (who knows when) on a XC fork that has axle.

There's no fundamental reason why not but it would be an unusual combination. Through-axle fork with QR rear is much more common.

Bear in mind though that there are good reasons why through-axle designs have replaced QRs over the last 5-10 years. It helps make the fork stiffer and it prevents any chance of the front wheel being ejected from the dropouts under disk braking forces. You might also find it harder to find a suitable quality front wheel these days if you're restricted to QR compatible hubs.


I cannot insert noodle to reattach front vee brake Removed front wheel to transport bike from 4 week stay at bike shop for tune up.  At home, I cannot insert noodle to reattach bike.  It's like cable is too tight.  Contacted repair guy, who said I could use a hex wrench to release cable a bit.  It's on so blasted tight, I cannot budge it. (Senior lady here!)
Does anyone have any suggestion on how to make this work?  I do not have anyone nearby to help.   I do not want to return bike for another lengthy stay at shop.
The adjuster does not give me enough cable to pull the noodle enough to seat it.  When the repair guy removed the wheel at the shop, he certainly didn't use force.  Someone suggested letting air from tire, removing it, inserting noodle and then pumping tire back up.  Perhaps I that is worth a try????

First of all, make sure the cable housing and cable is seated properly everywhere.
Even then it can be tricky to get the noodle back in and it can require quite some force to compress everything far enough.
If it’s just a matter of a few millimeters: You should have a barrel adjuster at the brake lever (marked C in the photo below) or at the brake. Unless it’s already fully screwed in, you can further screw it in (clockwise rotation) to give you slightly more slack. Make sure to screw it back out (counter-clockwise rotation) after you’ve inserted the brake noodle to bring the brake pads close to the rim. You should be able to pull the brake levers without them touching the handlebars. It’s a good idea to pull on a single brake lever with the full strength of both hands to make sure everything is seated and there is no give anywhere.
You could still try to unscrew the cable clamping bolt. A few tips for that: Make sure you use a good hex wrench and have it seated properly in the bolt, you don’t want to slip and damage the bolt. Use some WD40 or other penetrating oil if you have it. You can also try to heat it (using a torch, or even a hairdryer at hottest setting could work). And of course make sure you are turning counter-clockwise ;)


Bent rear derailleur (RD-5701)? I was cleaning the chain on my CX bike today, and while cleaning the rear derailleur I noticed the following:
When moving the cage from one extreme to another, the cage body will rub against the derailleur (main?) body at one point somewhere around the middle point of its movement range.

Please see the linked video which will hopefully clarify my explanation:
VIDEO

I don't think this is normal so I guess I would like a confirmation whether the derailleur is bent or not, or there is some other problem. It is a relatively new Shimano RD-5701 middle cage derailleur which has possibly received one abnormal knock when I was putting the bike into the trunk of my car.

The shifting is functioning pretty much OK except some difficulties at the two smallest cogs (I am using a 11-32 cassette), which I think are at least partly caused by improper adjustment of the derailleur and cabling, as the whole set is quite new so the cables and housing are definitely not yet worn in, but maybe this rubbing can be another cause?

I would be very grateful for any comments or suggestions.

I don't see any chain in the video.  It (most) will do that with no chain. The spring is (hopefully) strong enough to pull an untethered derailleur into the cassette.
Park Chain Length Sizing

Now the derailleur may also be bent but that is something different.

The rubbing in that video is only a problem if it rubs with the chain installed.


What PSI for downhill bike tires used for road biking? I bought a downhill bike from a friend awhile ago when I was considering trying out downhill biking. Currently, I want to use it to do some road biking. The tires read 29 PSI 2 bar, Max of 80 PSI. I pumped them to 29 PSI, and that biking session was pretty tiring. I pumped it up to 40-ish PSI and I can coast, and pedal much better. My friend at work suggests I pump it to the max of 80 PSI, but just want to be sure this is a good idea before I try it.

I'm pretty new to the technical side of biking/bikes.

Cheers.

Update: I forgot to mention that I read this post but it doesn't really mention road biking.

You will have lower rolling resistance at a higher pressure

A lower pressure puts more tire in contact with the ground for traction.
In the dirt this can be important.

But you are running on the street.
Yes traction on the street is also important.
But your downhill tires are not going to have good traction on the street.

Downhill bike and downhill tires on the street you are looking for low rolling resistance.
So pump them up to the max and no hair pin turns at 20 mph.

If you are going to ride on the street you could mount some street type tires.
And they have tires for a mix of dirt and street.

This is probably a duplicate some where.
I did not search.


How to properly adjust Look Keo pedals What is the best way to adjust the Look Keo pedals (mine are standard edition) so as to provide good grip, but with minimal wear on the cleats themselves? I use RED Keos.

Thanks

If you're never walking on the cleats and can track-stand at junctions and traffic lights they should almost never wear out.

There is minimal wear clipping in and out. The reds are 9 degrees of float before unclipping which may increase the wear though. I use the black cleats (0 degrees) and I wear out the bottom of the cleats through walking and stopping/starting long before I wear them out from riding. In fact, I'm on only on my second pair in 4 years.


Want to adjust/replace front fork suspension on a Next Break Point pro 26" bike. Has no access at the axle. Very 'low end' fork, bottoms are pinched at axle point, so no access there. Is there a way to clean, adjust these or is fork replacement my only option?

Low end forks are generally not repairable. The primary reason is that spare parts are not readily available. They can however be serviced. The labor involved would make it prohibitive to pay for the service as it will likely exceed the forks' value. Most can be disassembled, cleaned and greased. Remove (read this as pry) the plastic caps on the upper legs. With a flashlight you should see an allen head screw (5mm head) very deep in the fork. To loosen it requires either a very long wrench or a 3/8 drive allen socket and a long extension. Back off both screw evenly keeping track of the number of turns. Back off the screw until the lower section separates. You can clean any rust from the section and apply a general purpose grease to the moving parts. Then reassemble tightening the screws the same number of turns they were loosened. Just remember this is just service not a repair. Any parts that were worn are still worn.


How do I fix a puncture? I got a flat/puncture on my bike tube, how can I fix it myself without going to the nearest bike shop? What kind of equipment would I need?

Replacing a tire isn't that hard, but it will take a few times for it to seem like second-nature. If you have a road bike with skinny high-pressure tires, you can expect that the tires will be harder to remove and replace.

This is how I do it on my touring bike, offroad bikes, cruiser, and folding bikes. You'll need a pump to match the valves used on your bike (presta or schrader), a spare tube, and a place to work. Tire levers would be quite helpful.

Deflate the tire (if it isn't already completely flat).
Remove the wheel from the bike. This will probably require that you disconnect the brakes (if you have rim brakes, as the vast majority of bikes do). If your bike doesn't have a quick-release hub, you'll need a wrench for this.
Remove the tire from the wheel, if possible with the tube still inside. You may need a tire lever for this; it's a small plastic dookickey you can get in any bike store for a few bucks, usually in sets of three. You use it to pry the tube over the rim by working the edge of a tire lever under the edge of the tire and prying it over the edge of the rim, then sliding the edge of the tire around the edge of the rim; the tube should pop off when you've completed a circle. Two or three levers makes working with high-pressure tires easier. Once one edge of the tire is off, pull the whole tire and tube off the wheel in the direction of the side you were working with the tire lever, starting on the side of the tire opposite the valve. (Using a flathead screwdriver for this is not advised, as this can scratch the edge of the rim, potentially damaging the wheel. With some lower-pressure tires (such as mountain bikes or children's bikes) you may be able to remove the tire from the rim with no tools at all.)
Search for the object that made the puncture, and remove it. This may be a thorn, or a nail, or a piece of glass, but whatever it is will likely be sharp, so be careful! You may have to feel around with your fingertips, or submerge the tube in water and look for rising bubbles, or even turn the tire inside out. If you replace the tube without finding the object that caused the flat you may well get another flat. (If no cause for the flat is presenting itself, you may be getting a flat from the rim itself or a spoke poking the tube.)
Get your spare tube and put a little air in it, just enough to place it on the rim.  Put it on the tube, with the valve poking through the valve hole in the rim.
Replace the tire over the tube, pinching the tire to be sure that it's not pinching the tube as you inflate the tube inside the tire. Be careful that the tire is inflating evenly; the first few times you do this, you may want to inflate it a little at a time and check as you go.
Once the tire is inflated, re-install it on the bike, and please make sure to tighten your quick-release and hook your brakes back up.
Get back on your bike and enjoy your (for now) shiny new tire!

Watching a video or seeing pictures probably makes this all seem simpler; the other answers provided links to these resources. Bonus: More information that you'll ever need to know about tires and how to replace them: What Every Cyclist Should Know About Flat Tires


How can I improve my pedal stroke? I know a part of biking endurance and speed come from having a perfect pedal stroke. What should I do to improve my pedal stroke?

Pushing down on the pedals is a natural thing. So to improve the "roundness" of your pedal stroke, completely ignore the down-stroke, instead focus on the following:

Continuing the pedal stroke "across the bottom". This will probably feel something like trying to scrape mud off the bottom of your shoe.
On the up-stroke, focus on driving your knee upwards toward the handlebar.
At the top of the up-stroke, focus on sliding your foot over and down into the down-stroke.

Focusing on the non-instinctive 3/4 of the pedal stroke has really helped me improve form.  Using a fixed gear (or staying in a low-ish gear), find someplace where you can spin out your cadence (a slight down-hill but not too steep).

Focusing on the 3/4 of the stroke that isn't pushing straight down, pedal as fast as you can until you find yourself starting to bounce. Keep doing this, and as you get better at the non-down-stroke, you'll find that the pedaling cadence at which you start bouncing will get higher and higher, as your pedal stroke gets more round.


90 mile round trip work commute I'm looking for a bike that would work for a long commute to and from work, around 45 miles each way, country roads and some city traffic.  I am a pretty experienced runner, and can do my barefoot 10 - 13 mile trail runs 4 - 5 times a week, and I feel I can handle the physical toll.  I've done a 20 mile commute, to and from work, and my boss lets me shower in the mop sink / freshen up and change.  Any recomendations?

90 miles is roughly 140km, so if you're riding that every day it's about 700km a week. Which puts you in elite rider territory for upright bikes without power assist.

It's doable, it's just going to be hard and you'll need to work on nutrition and health as well as fitness. Note that there's also a balance here - if you use world class equipment to get a bit more speed, but need extra recovery and dress/undress time, you might not gain anything. So it might be better (as well as a lot cheaper) to go with elite level gear. I've assumed you'll do that below. You could drop further down that scale, but you will start to lose overall and also the sheer time involved will mean you can only sleep, ride, work (you're already looking at riding 4 hours a day, working 8, sleeping 8, eating 1... that's 3 hours for everything else in your life).

If you're just going to buy a standard elite road bike ($5,000+ and riding kit $1,000+), I suggest joining your local club and buying whatever their favourite bike shop recommends. It will probably help to have two bikes so you can get your weekly service done without having to panic about whether your LBS can get it done in time. Especially initially, you're probably going to need to ride alternate days, and you'll benefit greatly from going on your club training rides once a week or so rather than commuting every day. That way you get training tips and someone to help you understand how your bike works and how to get best use out of it.

One option is to buy a power assisted bike. You'll need to look really hard at battery life, and if you can get a second charger and leave that at work it'll be much easier. I'd also buy two batteries, because 90 miles a day is going to hammer the battery. From your use of imperial units I'm going to guess you're in the USA, which means power limits are hard to predict (they vary haphazardly around the US).

Note that most ebikes and kits are designed to boost low speeds only, and in Europe you can't boost high speeds at all (assist has to cut out at 30kph). So you'll need to shop specifically for kits that will boost you at 20-30mph. Those exist, I've seen a couple of triathalon bikes set up with 500W front hub motors that could cruise at 70kph/45mph for an hour... but those were "money no object" demonstration units at a world solar challenge.

A recumbent is the obvious way to deal with some of the problems. If you choose a fast lowracer or highracer style bike and use bright lights to compensate for the lower profile you will get better comfort and similar speed, assuming your ride is relatively flat. The big win really is comfort - you won't be fighting saddle sores anywhere near as much as on an upright, and you won't be as sore after the ride.

The lowracer style (on the left) is slightly faster in a time trial, slightly slower in a slalom, but you're in a time trial. The main reason to buy a high racer is wheels - they typically use 700c wheels so you can use the wheelset off your existing bike, or buy them easily anywhere. 406 wheels for lowracers are typically harder to find and there's not the intense market contest to get you really nice wheels are a reasonable price.

Combining those two will require a little more work, but a recumbent will probably take a power assist kit better than the road bikes you're looking at. IMO this is the way to go, as you get a small, light, fast bike at a reasonable price (under $10,000). If you did put a kit into your front wheel it would be relatively easy to swap in and out, so you'd only have the wiring and battery mount in place when you wanted to leave it at home.

The no-compromises approach would be a velomobile, possibly with power assist. The Trisled Avatar is designed to go 50kph/30mph using 200W from the rider. Other velomobiles give similar numbers, especially if you pay extra for the fast versions. If you're fit enough to consider riding 90 miles a day, every day you should be able to exceed that fairly easily. That would cut your commute time without compromising your body the way staying in a time trial tuck for 90 minutes would. I believe someone in the USA is doing a 30 mile each way commute in an Avatar. (full disclosure: the Trisled factory owner is a friend of mine).

Trisled don't support electric assist, but there are other fast velomobiles that do. The eWAW is one, but their focus is on helping with stop-start riding so you'd have to talk to them about getting better top speed on long rides. The Avatar is about $15,000 in the USA, the eWAW starts at about 7,000 Euro(google docs link, in Dutch)  but I think the electric version is 8,500 Euro.


27.5 x 1.95 tyres what sizes can i change to what other size tyres can i fit to these wheels? As I can only find mtb tyres and want to put a road tyre on? something faster with less tread

I manage a fleet of 150 MTB's that are used on city streets. The original knobby tires  wear down quickly. I replace them with Serfas Drifter City tires. These have three advantages: an inverted, long-wearing tread; built-in puncture resistance and more economical than the Schawlbes I run on my personal bike. They come in several sizes.


Apollo XC26 mountain bike, convert it to a coaster brake fixie? Hi a few years ago I acquired this bike:

It's a pretty crappy bike, it's cheap, poor quality parts and not really a mountain bike... but that is why i love it. It means i have to pay extra attention when taking fast sections of downhill, land properly when doing jumps and if anything brakes it doesn't really matter as the bike was cheap. I buy more cheap parts and get to learn how to build and repair a bike as i go, this bike is a learning experiment for me, as I do not want to spend £1000s on a good downhill bike i bought this second hand for £20 and rag it and then replenish the parts.

However i want to make some modifications; i would like it to be like an old school BMX:
 - Fixie
 - Coaster brake
Reason for this is the cables get in the way, the gear system is that inneffective twist shift, they don't work properly and it is just another cheap component that will break.

I know i can change this into a fixie, but can i also give it coaster brakes?
If i do will i still be able to somewhat downhill and jumps?
Thanks
Dan

EDIT

it is horizontal drop outs so i think it should be possible, but i have not had much experience

You can give it coaster brakes (but note that it won't be a fixie; it will be a single speed which can coast without peddling  with coaster brakes). Just buy or build a wheel with a coaster brake in it (you will need a coaster brake hub of the appropriate width) of the appropriate wheel size, put it in the dropout appropriately and then make sure to clamp on the reaction arm to the chainstay.

That being said, coaster brakes for mountain biking are generally not a good idea. They don't dissipate heat very well, and you have less freedom to position your pedals. On top of that, coaster brakes often lock up which isn't great. On top of that, removing a coaster brake wheel is more work than just a quick release (for flats, for example).


What effect does head tube angle have on a bicycle? My girlfriend and I are looking at a new bike for her. The one we're looking at has a 70 degree head tube angle while her current bike has a 70.5 degree head tube angle. Unfortunately, none of the local shops has one in stock for her to try out. So my question is:

How much does the head tube angle affect the fit and feel of a bicycle? I'm sure that it has at least some effect over the fit of the bicycle, but how much? And I'm guessing it has an even bigger effect on the steering, but again, how much?

there's a good write-up about this here: http://www.calfeedesign.com/tech-papers/geometry-of-bike-handling/

In general the steeper the angle the more agile the steering. If you like steeper you might say "quicker, more response", if you didn't like steeper you might say "twitchier".

A 1/2 degree difference is probably not going to make that much difference by itself. The other factors, which headset, installation of headset, stem length, handlebar type and setup, etc., will mask the differences here. As the Calfee page mentions, people will adjust very quickly.

Happy Riding!


Chain jumping, unsure why The chain likes to jump from the front sprocket, it is my impression that it makes no difference if the chain lies on the inner or outer cogs. Since I am unsure about the root cause I ask here for some pointers to troubleshoot the issue.

Bike:

The bike in question is an old 20" kid bike from a garage sale, history is unknown except that it is at least 7 years old. Former maintenance was neglected. It has an 1x6 transmission. The entire transmission is rather old and not the fanciest one. I do not have much experience adjusting the derailleur but in the end I was able to change smoothly to every gear (adjustment was done with the bike upside-down). The chain is well lubricated and has no stiff links. The entire transmission (front/rear sprockets, pulleys) moves smoothly.

Observations:

Observing my son riding the bike on the lawn I see the chain jumping a bit too much for my liking (amplitude about 10cm), I am not sure if that is fine.
When I tried to reproduce the issue I was able to "block" the chain between one of the rear sprockets and the jockey (upper pulley), I presume the issue was missing clearance between them. AFAIK there is no option to adjust that distance nor the spring tension.

Update

Closer inspection revealed that the large rear cog is definitely worn: The rear cassette will be replaced.

Update #2

I replaced both cogs, chain and derailleur (including cables). The chain behaves a bit better but still jumps from time to time from the front cog. The chain had a stiff link where I joined it, but that got resolved. The new front cog has no wobble. The rear derailleur is properly adjusted (smooth shifting to every position).

Frankly, I have no idea on how to proceed (Will post pictures of the new setup).
Perhaps I should mount a chain guard?

Additional thought: My son is just learning to shift. Perhaps I am overthinking that issue. Could it be that misuse (perhaps he is playing with the shift lever while standing) provoke most of the chain jumps? If so, would a chain guard limit the impact?

There are a few reasons that might cause the jumping of chains.

Chain or sprocket is worn out (Buy new ones).
The derailleur is misaligned (Needs adjustment).
The wheels are not fitted properly making it a bit slanted (clean the crevices
and fit the wheel properly).

Check all of these and comment back if all are good.


Can you change gear on your front dérailleur during a cyclo cross race? During the 10 cyclocross races I did this year I often found myself riding solely in my small 34t chainring and was unable to change up and down quickly enough between corners and barriers to be able to make use of my 46t. The group set usually takes 2-3 total revolutions of the cranks to do this if it doesn't drop its own chain. To remedy this I am planing on running a 39t instead but I just wondered whether more experienced people could help me find the answer.

I am racing on a 9 speed Shimano Tiagra and was wondering whether this is more to do with the level wear of the chain rings or if it could possibly be blamed on the budget level quality of the group set. Do Ultegra group sets shift quicker or are they more about weight saving, would the best place to start be a proper service at the bike shop?

It should not take 2-3 revolutions to shift modern chainrings. There are possibly a few things going on.

Your larger chainring does not have the pins and ramps required to shift quickly.

Sometimes cross sized rings don't have all the bells and whistles.

Your big chainring should have those features. If it doesn't get a new ring.
Race Face and Black Spire make 110BCD rings with pins and ramps in cross racing sizes.

The derailleur needs adjusting/replacing.

The derailleur cage needs to be positioned such that it is about 2-3mm above the big chainring. The cage also needs to be curved such that it closely matches the curvature
of the big ring. 46t is right at the size where a standard road derailluer has problems.
It should look something like this.

If you can't get the derailleur close on both top and bottom, you can either get a cross specific front derailleur, or grind the cage of your current derailleur to match the curvature of the big chainring.

Your shifting technique needs practice.

As someone who learned to shift before indexing, I have some habits that I only recently learned modern beginners often never learn. Even with indexed shifting, on the front you need to push the lever beyond the click until you hear the chain catch. This is something I was doing unconsciously since that's what friction shifting requires, a slight overshift and trim. Recently in helping a beginner learn to shift, I took a closer look at what I was doing and they weren't and realized that they let go of the lever as soon as it clicked, not as soon as the chain engaged the big ring. This makes a big difference in how fast the chain shifts.

They also needed to learn the subtleties of soft pedaling during the shift.

Modern chains and rings have gotten so good that in normal situations ( 39/52 on the road), you can often go a long time before these tricks become unconscious. Cross racing is tweaking the boundaries of what the shifting system can do for you and requires learning these old school techniques.


Spraying frame of GT Transeo I've got a GT Transeo 1.0 bike (bought in 2011 or 2010 as  best as I can remember) and I'd like to try painting the frame to get rid of some (very minor) surface rust and paint damage.

I've read a bunch of tutorials on spray painting bike frames, and they tend to make a distinction between steel and aluminium frames.

However the official GT website claims that the frame of my bike is made up of "6061 Alloy", which I assume is a reference to an aluminium/magnesium/silicon alloy, even though there is no mention of aluminium anywhere. Is this what is usually meant by an 'aluminium frame' online?

If not (or even if so) what brand of primer+paint+topcoat would work well for such a frame?

As for your alloy question, yes. The alloy specification itself is just the grade of aluminum used. Similar to the way you would find the type of steel used to make a knife or similar things like that.

As for what type of spray paint to use, I would recommend a Rustolium metal paint. Go to your local hardware store/paint store and ask them for a specific recommendation as far as aesthetic properties of the paint, but the brand itself is particularly tough and holds up well in different weathers, as well as different levels of abuse.

Just a quick personal tip; with any paint job, the preparation is always more important, and a bit more time consuming, than the actual painting of the item. Be sure to sand, buff, and clean your frame the best you possibly can. Adding new paint on top of old will ultimately look pretty bad, and your paint will most likely start to chip. Painting on top of dirt, old paint, or cracks may result in a lazy looking paint job.

So, in short, sand it down, clean it up, make sure it's dry, and go to town!


How to slow down a kid's bike In the show Yowamushi Pedal, the main character starts out riding a mamachari or "mommy bike" that he has owned since fourth grade. Now he is in high school. In season 1 episode 3, one of the other characters points out to him that in order to go faster he needs to raise his seatpost, and also that his bike has an unusually small front chainring. His bike only has one speed, and because this chainring is so small, he has to pedal at a very high cadence to go fast. The other characters speculate that his mom had the small gear installed for "peace of mind," so that the higher cadence would tire him out and keep him from riding too far away from home.

My question: The show made it sound like this is commonly done in Japan. Is this done in North America or Europe? And if so, what is it called in English?

This is not common in America.  Perhaps in Europe in places where cycling is more common, but I'm going to say it is going to go the opposite way:  going to higher gearing to get the kid going faster, or even to go to lower gearing to if they have trouble getting them going.

As for America, we don't really buy kids bikes with specific gearing.  It is something that isn't advertised for the bike (unless that is the major selling point of the bike).  Many of the 1 piece cranks we have are not capable of swapping chain rings.  However, the rear hubs still use the common 3 spline interface for single speed cogs.  I have swapped out the rear cog on a kids bike that we used for mountain bike trails because the gearing was too high for the kid.  However, despite the popularity of mountain biking in my are, my kids seem to be the only ones doing it on a 16" bike.


Front disc brake wobbling / grinding on pads after full braking and minor plunge The front disc brake grinds after a light accident with full braking and plunge.

To give an idea of the forces involved:

The bike fell to the left, mostly cushioned by me. The bike had no more linear
momentum. The brake lever and handlebar band has minor scratches. The handlebar
or stem is slightly skewed.

It look like the wheel/rim is not deformed/buckled, it's not visibly
wobbling.
The disc is slightly deformed, wobbling at most a couple of 100µm. The
bending cause by the pads looks more than a millimeter.
The gaps between disc brake pads are not even, one pad is always touching
the disc. The disc seems to be not centered in the brake.
The handlebar is slightly skewed (de-justified stem/steer tube).

The animation shows the brake photographed from the front toggling with brake
released and slightly, but not fully pressed:

From the animation you can see that the brake pads are not evenly spaced. On the
left (inner) side there's a (wide) gap, while on the right (outer) side the pad
is already touching the disc. Also, the disc is being pushed and bent by the
outer pad moving.

(Note that the animation was created from two photos taken with the bike
standing but being unfixated and the levers being operated. This causes some
minor movement of the whole bike. If you think this makes the judgement
impossible, tell me and I'll try to make a better pair of pictures.)

The animation shows the wheel spinning in 90° steps, photographed with sharp
angle to (along) the fork:

The wobbling is quite visible.

There's no more than these scratches caused by the plunge:

Technical data

Gravel bike
Carbon fork
Through-axle
Aluminium drop bar
Shimano 105 BR-R7070 with dual pistons
1200 km driven, 4 months old
Bike: 10 kg
Saddle bag and water bottle: 3 kg
Me including backpack: 65 kg

Course of events

This is after full braking and a - presumably - light plunge from standing. The
front wheel locked, the rear wheel lifted off the ground. The bike was upside
down (angled 45° - 90°) and I had the saddle in my spine before I fell fore- and
sidewards.

So I pushed downwards and sidewards (along the axle, not in driving direction)
into the stem with my body weight and a bit remaining momentum. There probably
was torque by the fork into the axle.

Questions and guidance

Is is possible that the braking energy itself might have

deformed the brake?
deformed the disc?
damaged the wheel hub?
deformed/invisibly fractured the carbon fork?

I'm pretty sure the bike pluging did no major damage.

What was stressed most during braking?

What components shall I replace (apart from re-justifying) to be safe?

Apart from asking a professional bicycle technican for an estimate, are there
things I can check for myself?

Might the fork be damaged by the aforementioned forces?

More background

This happened during a light traffic accident.

Ask for details

Ask for details, more part numbers, measurements or other photos (i.e. of the
scratches) if required to gauge this. If you think there's too much distracting
information, tell me and I'll remove it.

History of later clarifications/additions:

Clarified: double pistons. Rephrased/deduplicated "Course of events" section.

Two possibilities - the wheel itself have shifted, unlikely with a though axle though.  The crash does not seem to have be bad enough for a major damage like deformed hub to damaged carbon fork (Carbon is far tougher than many people make out and tends to fail catastrophically). However, if you have concerns over the fork,  get it checked by a bike shop.  While the risk of damage might be slim, the consequences if the fork fails are about as bad as it gets.

Its likely that the caliper has taken a knock and shifted on its mounts. All that will be required if this is the case is aligning the caliper.  Refer Park tools website for detailed instructions  https://www.parktool.com/blog/repair-help/hydraulic-disc-brake-alignment

The short version is to loosen the caliper bolts, apply the brakes gently hile spinning the shell, as you tighten the bolts slowly and carefully. This will center the caliper and and alight the pads with the disk.


SPD cleats damaging mountain bike shoes Hoping you guys could help me. I recently bought SPD cleats and as mentioned in this forum I've been using spinning bikes to practice unclipping.

I've noticed that my right shoe is getting damaged with the cleat. As in it is grinding into the sole of the shoe and scraping it. I am having difficulty unclipping this shoe.

Strange thin is I'm not having this issue with the left shoe. Ive tried various spinning bikes and I have the same problem.

I'm afrain I'm going to grind a hole into my sole.

Please help. :-(

Most probably you have not screwed it in tight enough. Cleats have to be screwed to the sole really tight.

Because the cleat is so small compared to your leg, there is a huge leverage being applied to it when clipping in/unclipping. If it's not tight enough, that's just what you can expect - it will move against the sole at pressure and grind it down.


Shimano front-derailleur with 28.6 Clamp For my new Shimano M780 based gear I need a pull down (or bottom pull) front derailleur with a 28.6mm clamp for a 3x10 without direct mount. All the derailleur I have checked do not have a 28.6mm clamp. Are there not produced anymore? And if so, what would be the solution?

You can buy a braze on derailleur of the type you need and get a Braze on to 28.6 adapter. Alternately, you can get a derailleur with a larger size and get a shim. Either will be perfectly functional. Very few Mountain Bikes have 28.6 downtubes anymore so the likelihood of finding a 28.6 seems pretty low.


FC-RS510 Crankset compatibility I've recently acquired a cyclocross bike (Stevens Prestige) with aforementioned FC-RS510 crankset. I am thinking of exchanging the 50-34 gearing which is currently mounted with a 46-36 set because otherwise my typical commuting speed would be just between the larger and the smaller rings.

Since the crankset seems to be a slight cost compromise in an otherwise excellently spec'ed bike, I am contemplating upgrading this part in the process. Can I mount any 11-speed 105 or Ultegra crankset? Or to spend slightly less but still upgrade, could I use 105 or Ultegra chainrings with this crankset?

If anyone could point me to the "famous" Shimano compatibility charts and how to read them, this would be much appreciated!

Short answer is yes, you can swap in any 11 speed crank that uses the same bottom bracket standard, which on the Stevens is a 24mm axle Hollowtech II type. I believe all Shimano road cranks are compatible with that.

If you are considering a 48/34 or 46/32 crank you'll need to drop your front derailleur down. There can be issues with braze on brackets not going low enough, but the Stevens seems to have a clamp style so you should be OK.

Links to the Shimano pages:

Shimano Specifications & Technical Documents

Front Drivetrain Compatibility

Reading the compatibility chart is actually straightforward, components in boxes linked by lines are compatible. The chart looks complex because of all the component codes, but once you figure out how to read those it's easy. Component codes are two letter components type then the series. ST/SL= shift levers, FD= front derailleur, FC=front chainset, BB=bottom bracket, CN=chain, etc, etc. You can look up the series numbers on the Wikipedia Shimano page.


Cannondale MTB hydraulic brakes Brake lever pulls straight in to handle bar and brake not working, have tried putting more fluid in but it’s still not working,has anyone got any ideas?

Your first step is to attempt to bleed the system. The principal that makes hydraulic brakes work is that fluid is not compressible. When the lever is squeezed, fluid is pushed through the hose to the caliper. The displaced fluid needs somewhere to go, so it moves the brake piston towards the rotor activating the brakes. When the lever is released the fluid returns to the brake lever. The piston move away from the rotor and the brakes are released. When air is introduced into the system the fluid doesn't move the piston it compresses the air bubble. This gives you the spongy feeling. The fluid used varies by manufacturer and model. Using an incorrect fluid type can ruin the system. The bleeding method also varies so you need to check with the manufacturer for the correct procedure.


Legality of opening someone else's car door? This is in the context of having just been involved in a near miss with the car. And only applies at traffic lights whereby the car is stationary very soon after the near miss. So, generally the near miss is to do with the car pulling across a cycle lane shortly before a set of traffic lights.

If their window is open it's easy to speak to the driver in order to elicit a response to "Do you know you nearly just hit me?". If their window is closed it's more difficult.

Knocking on the window is one option, and if that's ignored I've been tempted before now to simply open the door. Simply to prevent them from driving away before I've made them aware of their mistake.

So, my question is: is it legal, in the UK, to do so? The question of whether or not it's sensible to do so is one for another time.

If you opened someone's car door you could be committing either Dangerous cycling or Careless, and inconsiderate, cycling. (Road Traffic Act 1988)

There's also the offence of Assault to consider. (CPS guidelines)

  An assault is committed when a person intentionally or recklessly causes another to apprehend the immediate infliction of unlawful force.

Aside from the legality question, it's probably worth pointing out that many cars automatically lock the doors once the car starts moving and don't unlock them until the engine is switched off.


Using Anti Seize in place of Grease I bought Nickel Anti-Seize to prevent any corrosion issues between metals, and I generally like using it on my vehicles on bolts and anything I plan on removing later. I'm wondering where it would be appropriate for me to use Anti-Seize instead of grease on my bicycle, and where it would be considered a 'no-no.' The nickel type is very corrosion resistant, and temperature resistant to 2400 degrees.

My current thinking would be along these lines:

Desirable

Threaded Headset
Bottom Bracket Threads
Lightly on seatpost?
Cantilever brake mounts
Disc brake pivot points?
Threads on QR skewers / seatpost clamp
Other bolt threads

Maybe ???

Headset Bearings ???
Bottom Bracket Bearings ???
Hub Bearings ???
Inside fork tubes ??? (I have prothane grease because I have elastomers, but perhaps in spring forks it might be ok)
Chain (probably a bad idea, chain lube seems specially formulated and much thinner)
Spoke nipples (need loctite or nipple prep in this case, don't want the nipples to loosen)

Basically what I'm really asking here is, can I use it like grease in my hubs, bottom bracket, and headset? It doesn't really harden, and is rather lubricative, so what would happen?

Nickel Anti-Seize Data Sheet: .pdf

Anti-sieze is a corrosion preventer.

It is not a lubricant. Generally, using it on threaded parts is acceptable, but using it on bearing races, bearings, pressfit installation points, seatposts, handlebar stems, etc... is not a good idea.

There is no hard and fast rule, but if you think about the purpose of the "lubricant" on the specific part, you should be able to make a good judgement.

i.e. "Do I need lubrication for this part to move smoothly and work efficiently? If so, I should use grease."

or

"Do I need lubrication for this part to so that it is not stuck in the frame later? If so, I could use anti-sieze."


An Old Tandem. Need to Know the Maker I have an old Tandem Frame. The identification is the Number 311. Is it possible to identify the manufacturer just from this information

No. That kind of serial number hints at a small builder who just numbers all their frames sequentially, which is a practice any number of them have used.


V-brake arm not returning to "open" position I have a folding bike with v-brakes and I noticed that when I pull on the rear brake lever, one arm of the v-brake doesn't go back to its original position. I tried adjusting the screws but it still doesn't go back. Although I'm not entirely sure if, when it stays in place, it hits the rim.

What could be the likely cause of this? The spring? Lubrication? Thank you.

There are a few possibilities but its fairly easy to isolate the likely problem.

Unclip the noodle (where the cable comes out) and check if the problem is in the V brakes or the cable.

If its the V brakes, it could be a broken spring, or the brakes need oiling.

If the brakes are free to move and spring back firmly, its likely a problem with the cable or the brake lever. Without pulling the cable out of the housings, slide the cable back and forward - it should be free to move. If not, check the brake lever is free, or it could be a corroded or kinked cable. If its the cable, a replace is only a few dollars and is the best option (I almost always put in new outers as well). You can try adding some lube to the cable  and working it, its usually successful but never as good as new cables. If the cable is kinked, you may have luck straightening it, but again, a new cable is always a better option.