Beginner always sliding forward on seat I'm 250 lbs and have been riding for about three months now to lose weight. During my rides I always feel like I am sliding forward on my seat. Because of this I never feel like I'm sitting on my seat and whenever I rest I usually end up supporting myself by standing on one pedal or the other.

Because of this (I think) my hands and feet go numb. This happens about 20 minutes into my ride. Different types of terrain don't seem to matter. Then it becomes a game of shaking out my hands and feet to get the blow flow back until the end of the ride which is usually an hour. I'm getting to the point where I am ready to increase my ride duration, but the pain in my feet and hands concern me. I initially thought it was just my body getting used to the bike, but now I'm not so sure.

I've tried moving my seat forward and backwards with the same result. I've tried adjusting the nose of my seat upwards, but it caused a worse pain in a much more delicate area. I have bought gloves with thick padding which helped a little, but not much. I went to my local bike shop and bought the pedals and shoes. The new shoes caused me even more pain than the sneakers I had been wearing. The shop owner asked me to pedal on my bike for a while so he could watch me and he didn't see anything abnormal thought he is not a fit specialist.

My last hope is to go to a specialist for a real bike fit, I'm just anxious about spending more money for them to tell me I've been riding the wrong bike, wrong shoes, wrong seat. Everyone I talk to gives me the look like they don't have any idea what I'm talking about when I mention it. Could it be that I am just that out of shape?

Edit for additional information:

I'm 5'11 and I'm riding a specialized 56cm road bike (pic). I do wear bike shorts and I have gotten over the initial saddle soreness phase and my sit bones don't have any discomfort compared to my feet and hands. I ride currently with my saddle horizontal. I get the sensation that my sit bones want to slide forward and straddle the skinnier part of the seat. I have tried just going a long with it during one ride, sliding forward. This resulted in my tailbone being extremely sore for a week.

I'm a similar weight to you and your description is very familiar. I'm almost certain that your saddle is angled down too far. If angling it up enough to stop you slipping causes it to put uncomfortable pressure on your perineum then you probably need a different saddle.

Some people are fine with whatever comes with the bike but I've tried maybe 10 saddles at this point and haven't found one that works well for me. On the bright side, I'm slowly understanding what works and what doesn't.

I'm overweight and it sounds like you are too from your question? I think the extra fat causes issues with the saddle putting pressure on the soft tissues. It also means that gravity is pulling you harder into the saddle.

My poor solution for a long time was to buy a really wide saddle, point it upwards slightly and tilt my pelvis back/arch my back to keep the nose from putting too much pressure on my perineum. This isn't very comfortable though and it seemed to be hard to put out much power. I've recently switched to a bike with a more leant-forward riding position and, while it is great in a number of ways, my old solution absolutely doesn't work.

Here's what I'm looking for in a saddle:

Width - One thing that is immediately obvious to me is that regular width saddles are too narrow. This should be to do with the spacing of the parts of your pelvis that you sit on (and your riding position) rather than having anything to do with weight/fat. I am pretty broadly built so this might not apply to you.
Quantity and softness of padding - Hard, thin padding is better. Lots of soft, squishy padding causes issues with chaffing and when you sink into it, it rises up and puts pressure on your soft bits. I think if you are overweight you need harder padding than normal since you are already more prone to issues with chaffing and because you will sink into it more than a lighter person. Also, I'd rather have bruised bones than a numb penis. Annoyingly, harder saddles are almost always narrower.
Get one with a cutout - Some people like cutouts and some don't but I suspect they are necessary if one is overweight. They can have their own problems though as they can concentrate the pressure along the edges.
Shape - This is really important but it is unfortunately impossible to give recommendations since it is very personal.

Trying out saddles is difficult. Some bike shops have loaner saddles but such places are rare. If you know any cyclists then ask them to led you any spare saddles they have, and ask them to see if their friends have any spare saddles. Even if none of these are comfortable they should give you a better idea of what works and what doesn't.

Extra thoughts:

What kind of seatpost do you have? Some use notches/teeth to hold the saddle angle and in my experience the adjustment on these can be too coarse: one position is too far pointed down but one tooth up is too far pointed up. If you have a seatpost like this that might be the issue as the angle adjustment needed on a saddle is pretty subtle.
"Everyone I talk to gives me the look like they don't have any idea what I'm talking about when I mention it. Could it be that I am just that out of shape?" From bitter experience I know that if your issues are being caused by being overweight then someone who is not overweight probably cannot comprehend it and many will write it off as "not a real problem" even if they are otherwise an expert. I would look for advice from other people in the same boat as you.
From your question I've made the assumption that you are overweight (as opposed to being muscular) but I don't know if this is actually the case. If you are a bodybuilder than some of what I've said holds and some doesn't.


Spokes loose on a new wheel, is this expected or a bad build? So a couple of months ago, I bought a new front wheel from the local bike shop. It's a 28 spoke wheel, rims are the DT Swiss RR465 and the hub is a 240s.

I put 500-600 km on it and noticed a rattle after a ride. After isolating it to the wheel, I noticed that 3 of the spokes were extremely loose with one of them basically hanging. (The nipple/screw thing appears to be inside the rim somewhere.

Anyhow, I'm pretty sure I didn't hit anything and I'm not a terribly large guy. Are there things that can happen to new wheels/spokes, stretching or coming loose? Or is this a case of the LBS basically doing a crap job of building the wheel?

I'm nearly positive I didn't do anything wrong here, but I'd like to know if there was any possible user error.

Apart from an impact, if it's been twisted in a bike stand wheel slot or something that could cause loose spokes. But usually loose spokes on a near-new wheel is just a bad build - if the spokes haven't been stress relieved properly they'll generally untwist as you ride it. And some wheelbuilders don't use a spoke tensiometer so regularly produce wheels that loosen over time.

Either way, take it back to the shop and ask them to fix it. When you collect it after they fix it, pay very close attention the very first time you put weight on the wheel. The first revolution with load on it is crucial - if you hear pinging noises that is the spokes untwisting themselves as the tension goes off them (the ones at the bottom have less tension due to your weight pushing down, so there's less resistance to them untwisting). That means the wheel hadn't been stress relieved properly (because you just did it), so the spoke tension might not be correct any more (and the wheel might no longer be quite true). If the problem happens again take it to someone different - someone who can't fix a wheel they built is not worth your time.

In more detail: as a wheel is built or trued each spoke nipple is turned. Because there's friction between the nipple and the spoke, this tends to twist the spoke as well as tightening or loosening the thread. Stress relieving means (gently) applying force to the wheel to momentarily loosen each spoke, allowing them to spring back into the non-twisted position. This slightly reduces the spoke tension, and may even unscrew the spoke slightly out of the nipple causing further loss of tension. So after stress relieving a good wheelbuilder will recheck the spoke tension.

EDIT by an anonymous user: Bladed spokes shouldn't twist because as they are built they are held with a tool which does not allow that.

A good wheel is not just true, it has even spoke tension. Over time uneven spoke tension tends to pull the wheel out of true, and the tight spokes are more likely to break in an impact, while the loose ones are more likely to break from metal fatigue. There's much discussion of this online, and Jobst Brandt's "The Bicycle Wheel" is a deceptively concise but detailed explanation of a lot of the issues. It's worth buying a copy if you're interested in wheelbuilding (I don't get anything out of you buying the book, I just think it's an excellent book).


What is the proper way to paint a bicycle? I started a while back restoring a custom-built tandem bicycle, and I sanded it down to bare metal and just used spray paint (Rustoleum I think, took the bike completely apart to just paint the frame) to give it 5 or so coats, then a clear coat... but the paint still comes off pretty easy. To paint it up I just hung it up by the back forks and did light coats. Anyways, it looked good in the end, but the paint still comes off pretty easily.

What are the steps that someone should take to fully paint a bicycle that already has a coat of paint on it, that is tough and good looking?

If you're going to use paint, I have had some success with the following:

Bead-blast (or sandblast) the old-paint completely off the frame. Sandpaper just isn't as good. You can rent a bead-blaster.
Clean thoroughly with ethanol and rags. A white rag should stay clean if you rub it on the frame by the time you're done.
Prepare a clean environment for painting. Get a roll of plastic tarp and literally make "a tent" in which you hang your bike. Cut slots in the wall so you can stick your hand in and apply the paint.
Apply the appropriate primer coat (critical for success)
Apply layers of the spray-paint color (this is where experience makes a difference, I tried really hard to get it uniform but only pros can really get it right).
Apply clear coat.

As an alternative to paint, you can have your bike professionally powder-coated. This will give really beautiful results. I have had this done, but had problems with a lugged frame. After a few years, I can see that the powder coat has started to admit rust in the edges of the lugs. It is probably better to reserve powder coat for fillet-brazed (tig-welded) bikes. I am not sure if there are special preparations needed to powder-coat lugged frames.


What would I search for to find bike hubs that attach on only one side like found on tadpole recumbent What is the name of the hubs used on recumbent tadpole trikes. Those tricycles that have two front wheels and a conventional rear wheel

They are often referred to as just that, a tadpole trike hub assuming you're looking for the front hub. They differ from standard trike hubs slightly. If you are in the united states or Canada you can get on of these from a shop. Let me know what country you are in as you are unregistered and I will do my best to answer.

http://www.jbi.bike/web/checking_product_description.php?part_number=38751


Is contact patch area governed by A=W/P contact_patch_area = weight / tire_pressure

Is this true?

Wikipedia says "mostly".
This guy analyzed some automobile tire manufacturer, and although the info was self-conflicting, he concludes that it very much depends on tire construction, but the equation is for sure false. However, he bases some of the conclusions on the assumption that rubber acts as a constant-rate spring, which it doesn't.
This answer assumes it is true.

Assuming a 200 pound rider+bike+clothes+load and a tyre pressure of 100 PSI, and a nice even 50/50 weight distribution, then each wheel is supporting 100 pounds and should have a contact patch size of 1 square inch.

You could empirically measure this using a scale and a dry piece of paper, and a slightly dampened tyre.   Moisten the tyre and use its "footprint" on the paper.  Do the same with the rear wheel.  And then draw around the boundary with a pen.
Perhaps a dusting of talc powder on the tyre would work better than water.


Bike seat and post recommendation Yesterday someone stole my bike seat along with the seat post. I am planning to buy a new seat with post that fits it. My bike is a Bulls Pulsar mountain bike. I have found a seat on Amazon but I have not found a seat post that would fit this seat. I request for your help. Thanks.

https://www.amazon.de/dp/B07DB3KVPS/

and this is my bike:

https://www.radonline.de/bulls-pulsar-street-21-gang-kettenschaltung-herrenfahrrad-trekking-modell-2018-26-zoll-schwarz-matt.html

You need a "seat post" which has to be exactly the same diameter as the old one.

The specs page only says "Seat post: STYX aluminum" which is not enough information.

Your best option would be to close the clamp to its normal position, and measure the internal diameter of the frame using calipers.  A ruler won't be accurate enough, because while common seatposts could be in these sizes:

25.4 mm
26.2 mm
26.8 mm
27.2 mm
28.6 mm
31.2 mm etc

It is not impossible for the seatpost to be some weird in-between size.

The overall length of the seatpost is less important, only that it is long-enough.

You'll also need a seatpost with an integrated clamp at the top, or a separate clamp.  Very likely whatever you buy will have a clamp included.

Separately - someone has stolen your bike seat once already.  Expect that it will happen again.  Some relevant links to protect your parts:

Protecting quick-release seats and wheels from theft
Quick release saddle bolts?


Shimano cleats, Exustar shoes: Which bolts to use? I just got Exustar shoes and Shimano SPD-SL pedals with SM-SH11 cleats. Problem is, the cleat fixing bolts that were included with the cleats aren't long enough to bolt to the shoes. I'm wondering what length of bolt will work best for this? I'm seeing a lot of "extra long 13.5mm bolts" online- would they be long enough to bolt to Exustar shoes?

Any help greatly appreciated, thanks!!

Measure to make sure they are long enough. If they are too long, screw a nut on then cut it with a metal saw at the right length. Use a file to make it smooth then unscrew the nut to make sure the threads are nice and clean.


Worn out square taper bottom bracket spindle? I got an used bike with a worn out left crank arm. I tried replacing with a new square taper crank arm and torqued it to 40nm; however, it started creaking soon after and the bolt had become loose (I checked with a torque wrench).

Could the bottom bracket spindle be worn out as well? I did notice a very tiny bit of wiggle when I fitted the new crank arm before tightening the bolt.

Edit: the original worn crank was steel.

The square spindle (the best pic that I took):

The spindle looks a little rusty. That may be what is causing the the creak. Try completely removing the rust with a wire brush and thoroughly cleaning the crank and spindle before re-installing.

Be aware that the bolt can loosen slightly in use as the crank 'climbs' onto the square taper. See https://www.sheldonbrown.com/brandt/installing-cranks.html


Why the backwards fork? While reading this Wikipedia article, I noticed some photos of racers, all from the early 20th century, riding bikes with the forks installed backwards. I count at least 3 of them, so it wasn't just a single weirdo doing that. What is the purpose of this configuration? The downside is obvious (it makes the bike harder to control) but they must have had a reason.

As already said in the title of the Wikipedia page, these bikes are intended for motorpaced racing on track. The backwards fork allows the rider to stay closer to the derny motorcycle for more efficient drafting. Since the races take place on track, with single riders drafting motorcycles, the handling is not that much a problem, but people have indeed died in accidents in this form of racing.


Is there any advantage to using pedal straps over clipless pedals? Other than not having to buy special biking shoes, is there any clear advantage to using pedal straps over clipless (aka clip-in or step-in) pedals?

The biggest benefit I see is convenience.  You can just hop onto a bike with whatever you're wearing at the time and go.  Not a big deal if you're planning a 15 mile ride, but a real big deal if you're riding around the neighborhood, hopping off to run into a few stores, etc...

It's also possible to pedal on the flip side of the pedal and get moving without the cumbersome and slow start up that is required to get into clipless or straps.  In an emergency you can even stomp on the straps and move the bike out of the way.  It's rare, but occasionally you find yourself standing there and just want to get out of the way, in any direction.

I've now switched almost entirely to riding clipless though.  Between that and riding fixed gear, it makes the bike feel so connected to me.

To compare:
Straps are easier to get into.
Clipless are easier to get out of (really!).
I've never pulled out of my clipless pedals, I have broken a strap (no big deal if you're not in a sprint).

At this point if I'm riding any distance at all, I change shoes.  If I'm just going to the store to pick up groceries, I don't even have straps, just old school pedals.  The middle ground for straps just evaporated for me.


Can I put my 2.1" 29er tires on a wheel with 25mm inner diameter? So I broke my second front wheel last night when I hit a dip that rose too quickly for my wheel to climb before all my weight went behind it. I'm a big guy (300+ lbs), so my wheels need to be able to take a beating.

Right now I have a 2014 Specialized Rockhopper Comp 29er with the original fork, tires, and just about everything except the peddles and wheels. I upgraded to Mavic CrossOnes last year after I taco'ed the original front wheel on a hard turn.

I am getting tired of replacing these wheels. It is getting a bit expensive too. So I want to find some really tough rims and from what I read you need to get wheels that have a wider inner rim. The Mavics are 19mm if I remember correctly.

I am thinking about upgrading to a DT Swiss EX 471 29er rim which has a 25mm inner width. But I would like to stick with the ground control tires I already have and really like.

Would my 2.1" Ground Control tire work on this wider rim? I am also considering going tubeless. Also, any recommendations for stronger wheels for my heavy body?

According the Sheldon need 25mm for a 2.1"

A downhill wheel tends to be strong (and heavier)


Paint scratch or carbon crack? I might just be overly paranoid, but does the line in the image (to the left of the glare) look like a paint scratch or could it be a sign of a spreading crack?

I am not an expert. It looks like a scratch to me because of the curves and the way it doesn't end at a sharp point. However, it's impossible to really tell from a photograph so you should take it in to a bike shop and get them to have a look at it.


What is the maker and year of this frame with the serial number a2008112 I'm needing help identifying my frame with serial number a2008112 please help

You can easily identify the maker of this bike thanks to the gusset on the frame, it is a Mongoose.

The serial number starts with A, which tells you it was made in January (A : January, B : February, C : March, etc.).
Then the second character is a 2, which means it was made in 1982 (last number of the year).

So your bike is a 1982 Mongoose.
According to the manufacturing date, it can either be a Supergoose I or II, or a California Special, but I can't really tell with these picture. You would also need to know the frame material to help figuring this out.

If you need more info, hit that link : http://www.vintagemongoose.com/index.php


Will a change from 26x2.10 to 26x1.95 tires improve speed? If I change my 26x2.10 MTB knobbies by 26x1.95 slick tires, will I feel any difference on my speed on paved roads? or is it going to be the same? I am kind of confused about how much I should change the width of my tires to notice an improvement in my speed. The reason: I will be using my MTB to commute.

If you run your knobbies at typical MTB pressures, and you run your slicks at higher pressures, you should experience less rolling resistance, which could translate to higher speed.

I don't know what tires you're talking about exactly, so it's hard to say how much of a difference it will make. I run some pretty aggressive knobbies on my MTB (Panaracer Fire XC Pros) and with <35 PSI in them, that makes for some noticeable rolling resistance. On my vintage no-suspension MTB, I run slicks with 60-65 PSI in them, and those are halfway to being road-bike-like. Even with the MTB gearing, I can hold 15-16 mph on that bike for a decent amount of time.

You did not indicate what kind of suspension your MTB has. With any suspension, you're probably going to get a little pedal bob, which will rob you of some energy. That, combined with the upright riding position, will hold you back a little. But the engine (your strength) is more of a factor than tires, suspension, and bike weight.

Once upon a time a friend of mine-- road bike rider, likes Italian bikes, pretty fit at the time-- used to regularly get passed on a local muni trail by this little guy on a vintage mountain bike who was dressed in street clothes and riding to/from work. These roadies would be doing a paceline at a good speed, and the little guy on the mountain bike would just roll right past them, comfortably holding 2-3 mph faster. I wasn't there, so I can't tell you if the mountain bike guy had modified his bike or what. But he used to say "good morning" or something similar, every time he passed them, with a big smile.


is there an easy fix for worn down brakes? I have a really cheap Walmart bike with originally came with questionable brakes. After more than a year of commuting, they have worn down to next to nothing. Is there any easy fix at home to improve brake performance?

UPDATE: Brought it to a bike shop and they said its a mixture of cable stretch and worn brake pads.  Getting front and back brake alignment for $14

The easy fix is getting new brake pads.  The hard fix will be when they are worn down to metal and start to dig into the aluminum brake track of the wheel. At which point you will be better off getting a new bike rather than paying to replace wheels and brakes on a BSO.


10 speed rear derailleur to shift 11-40 cassette on 3x10 This is a switch from 9 speed to 10 speed.... I have a 10 speed FSA carbon crankset 52-39-30 I wish to run cassette 11-40 10 speed...  I will size chain length to shift 39-40 and 52-30 no interest in running big big.   Suggestions for rear derailleur and shifter.   I have read that Shimano SGS long cage with B screw all the way in will shift to 40 cog.   Thoughts?

For this setup you would need a derailleur with a capacity of (52-30)+(40-11) = 51 teeth.  This page states that the SGS has a total capacity of 45 teeth. That's seems quite a bit below what you are trying to do, even if you don't plan on running big/big.


Lighted ankle straps I read an article in the Wall Street Journal about a recent study that concluded that motion-based lighting is the most effective technique for drawing motorists' attention.  I believe the recommended that cyclists wear a lighted strap around their ankles so their leg movement will be visible from any angle.

Do any products exist yet like this?

Yes.

Since that's a short answer, here's some examples (without making any sort of recommendation)

http://www.dx.com/p/outdoor-sports-blue-light-3-mode-led-flashing-safety-armband-black-2-cr2032-425777#.WaxcC3Wg9hE

http://www.dx.com/p/outdoor-cycling-reflective-safety-3-mode-led-nylon-armband-w-buckle-green-2-x-cr2032-339927#.WaxcA3Wg9hE

Do consider the colour before wearing - In my country Blue (police) and Green (medical service private transport) are reserved colours that must not feature on a road vehicle.  Also Red must not face forward and White must not face rear (unless reversing)

I have used something similar to the blue one and it works as described, but they're not bright enough to see with.  2x CR2016 batteries don't last long, and CR2032 are only marginally better.

You could also get the same effect using electroluminescent wire and stitching it to a velcro strap.

The easiest solution is to use a small red rear light and clip it to the back of your traffic-side foot or pedal.  Some risk of it falling off though.


Can I run a 700c/28"/29er wheel & tire on a 650B full-suspension mountain bike frame? I recently bought a 2015 Giant Anthem 3 27.5" full suspension mountain bike to build into an electric bike, however, all my other bikes (road bike, other electric bike) have 700c/29er wheels, and I think 700C/29er wheels might be better for this particular build. My new 27.5"/650B mountain bike is running relatively thick 2.25" mountain bike tires, and it has just over a half-inch of tire clearance on the front fork as well as the rear swingarm/triangle thing. I would like to change out the 27.5" wheels for 700C/29er wheels with smaller tires (say, 40C/1.75" tires). My working theory is that it would fit just fine, because the increase in wheel diameter would be offset by the decrease in tire diameter. Is this a workable, advisable change? Could I use the same brake rotors (160mm discs front and rear) on the 700C/29er wheels? Assuming that 700C/29er wheels would fit on my 27.5" frame, should I potentially avoid adding fenders due to the tighter tire clearance?

The only way is to try it and find out. The great thing about disc wheels is that the brakes are in the same position regardless of rim size, so if you put the wheel in and it physically fits (i.e. it goes in the frame with enough clearance) and for the rear it has the right cassette, you're good to go (possibly with some minor adjustment to the brakes). If the outside diameter of the wheel with the tire on shrinks versus your 650b wheels with the 2.25" tires, it should work fine. If it grows, you may have to worry about clearance. You can check this by putting the wheels on top of each other.

That being said, reducing tire size may not work so well for actual mountain biking, so if you are going to take it mountain biking rather than electric biking on the road, you may want to stick with the bigger 650b tires.


Problems with spoke threads, and stressing the wheel I was building up a rear wheel with brand new spokes and nipples. I used linseed oil on the threads so that when it dries it hardens. When I stress the wheel/spokes the threads slip, causing the spoke to come out of the nipple, but it's can still thread the spoke into the nipple. Could this be because I didn't give the linseed oil a chance to dry a little bit. Or should I just use grease. These are just standard spokes you can get at the bike shop for a buck. Thanks.

There is one major cause of this problem and it is putting a 1.8mm aka 15ga spoke in a 2.0mm/14ga nipple.
This mismatch will screw together and hold under some tension, but then slip.
It is easy to test. Obtain a known 15ga nipple. If it can screw on to your spokes at all, it confirms the problem.
The same thing could happen with a 2mm spoke in a 2.3mm nipple presumably. Those are visually chunky though, whereas 1.8 and 2.0mm nipples look identical except for the hole.
I can imagine a fringe outlier situation where poor part quality alone causes this, but it seems really unlikely.
If the spokes were way too short, like with a bunch of thread showing, that may be able to cause it too, but you'd probably notice that.
Your prep choice is not the issue here. Linseed oil does take a while to fully set up, but it's not what's mechanically holding the wheel together. Ideally you complete the wheel before it sets up and gets gummy because it's easier to make small adjustments then.


Ivanhoe ladies with wooden rims, wooden rear fender, wooden chain guard Attic find, any thought as to age, options not on a stock bike, value range.

It's an Ivanhoe ladies bike made by the Indiana Bicycle Company between 1898 and 1900.
The company was founded by Albert Augustus Pope in 1898 and changed to the American Bicycle Company in 1900
Yours might be the ladies version of the Ivanhoe Special.
Check below the head badge and see if the lower badge use to be there

thread from The Cabe
The Indiana Bicycle Company also made the Waverly Belle which bears a strong resemblance to the Ivanhoe.

bicyclearts.com


Spinning bike's pedals are way bigger than the cleat pedals I have. What size do I need? I’ve bought a spinning bike that has the cage pedals. I have cleat shoes which I prefer to ride in, so I bought some cleat pedals to fit to the spinning bike. Trouble is I've just taken the existing pedals off, and the thread is way bigger on the spinner pedal than the one I have on the pedals I have bought. Is there a bigger pedal or adapter available?

Almost all adult bikes have 9/16" threads, with 20 TPI.  One side is left-hand thread.
The other standard option is 1/2" thread which is intended for children's bikes.
There are rare vintage standards around 10 and 12mm but your spin bike wouldn't have these.
Finally there's a chance your spin bike has some proprietary pedal thread.  Do you have access to calipers?
While pedal adapters do exist from 1/2" to 9/16" they are not cheap, and they separate your feet by some, also known as "increasing the Q factor"


What is the difference between KMC 410Z vs 710 chain? What is the difference between KMC 410Z VS KMC 710 chain?

For use in single-speed or fixed gear bike.

The 410 series is very basic 1/8" chain. It's one of the most populous single speed chains in the world. There are different color and finish options for it out there.

The 710 series is oversize heavy-duty Street-oriented 1/8" chain with nonstandard/asymmetric outer plates. It's thicker and is purported to have extra-strong riveting.


Help Identifying this Tandem? Sun Tourer I recently purchased a tandem bike frame on a whim, and am having some trouble identify the bike and manufacturer. If anyone is able to help with this, even help identifying the manufacturer would be great. I'm not sure if this is the same 'Sun Cycles Co' from Birmingham, UK, as the logo appears more modern.
Thanks.

Looks like a home-made tandem to me.
Here are my reasons:

The captain's seat post has no clamp.  Instead there's a hole, presumably for a bolt to go through the seat post.  That's not done on a purpose-built tandem.  Here someone's cut the clamp off to allow the top tube to continue.
I see a tang at the bottom under the Keel Tube for a chain tensioner.  A purpose-built tandem would be more likely to use an eccentric BB in the front for tension
That tensioner seems to be on the right-hand side of the frame - a normal tandem would have the timing chain on the left side, and would have special bottom brackets to account for this.
The stoker's position has a head tube of its own - normally a tandem would have a special stem that secures to the captain's seat post, bringing both riders closer together.  The larger the gap between riders, the less benefit you get from aerodynamics.
The welding on the stoker's BB housing looks different for the keel tube - specifically its a lugged frame but the keel is butted straight onto the lug, not into a recess.
I suggest you look closely at the rear of the captain's BB shell, for the remains of chainstays that have been cut off.  I do see the stoker's head tube has been extended with new metal that doesn't match, that will also be welded in.  You could also look at the sides of the stoker's downtube for the remains of shifter bosses.
The tube diameter of the additional pipe in the middle is higher than the rest of the frames - so between captain's seatpost and stoker's head tube is noticeably wider tube, as is the keel and the lower stoker's head tube.

The paint job looks like a can of spray paint, specifically where the white fades into the red.  To be fair that's a really hard transition to paint well.
So either the frame builder added some stickers after painting, or they welded it such that the original stickers stayed usable, and only the new welded areas got painted.
Please don't take this as talking down your frame - it will be a loverly bike when you've finished building it.  But don't waste too much time trying to identify the brand, when it could have been made by someone in a home workshop.


Does this bike use hydraulic brakes? Hi. I want to buy this bike. Is it hydraulic?

If there are no signs of a metallic wire (often colored silver) exposed anywhere near either end of the black housing "tube" connecting the lever on the handlebars and the caliper on the fork, it means that it is a fully closed hydraulic line. Another giveaway for mechanical brakes is a moving arm at the caliper which visibly reacts when pressing a lever.

On your picture, the front brake we see is clearly hydraulic.


Does anyone have experience with wooden saddles? I've been looking online at a wooden road saddle and it looks pretty sweet but not sure how comfortable it's going to be... The description says it's made from maple wood and designed to flex, so it sounds like it should be a decent ride. But, it's wood.. so...

Anyone have experience with a saddle before?

The description sounds like it is made up of multiple layers, boats built that way are very strong. Being thin, the wood will flex and return to its original shape – I wouldn't expect it to be like a Brooks saddle that molds itself to fit you over time. I think these saddles will be comfortable right out of the box. Or not. This article, The Four and a Half Rules of Road Saddles, helped me sort out what to look for in a comfortable saddle.

Check out the maintenance the saddle requires. If the wood is not well sealed or if the sealing material wears out over time the saddle will start to fail (both from UV damage to the wood and from damage to the glue joints as the wood expands and contracts as its moisture level changes).

Those are beautiful. Looks like parts are available too. Nice.


How can you speed a road-bike up? So, I have an 80's raleigh bike, reassembled from spare parts.  I'm wondering what the best way to get more speed out of the bike is.  Wheels?  Gears?  Lighter gear? Different pedals? I'm rather fond of the frame, so I'd rather not replace that.

Gabe,  If you love the frame, and are willing to spend the money to keep it, start upgrading everything else.  Start with:

Wheels/tires - rotating mass will slow you down the most - go to aluminum wheels and thin/light tires size 23 or 25.

Bottom Crank - Once again rotating mass, you can get some hollow core cranks, and adjust the chainring sizes to the biggest you can push.  You can save a few grams by going to a compact crank versus a triple.

Shifters/derailleur(s) - get some aero shifters/brakes, and upgrade to a lighter front/rear derailleur.

Seat post, handlebars, stem - On an old raleigh, they are probably steel - you can get inexpensive aluminum replacements.

Seat - get rid of the OG heavy seat and get something more comfortable and lighter.

From expensive and most effective, to least expensive/effective, thats the list off the top of my head.

Good luck on your decision, and keep those old Raleighs going, they are great bikes :)


Tire not sitting properly after changing spokes I've changed many a tire, but never seen this issue. It's not sat properly and is bumping against the fork (seems radially misaligned). Pretty sure the inner tube isn't pinched between tire and rim so unsure what the problem could be.

Let out the air. Then unscrew the valve stem nut almost up to the top of the valve. You can leave it off as they have no other function as to keep the valve from 'disappearing' into the tyre while installing a tyre. It won't happen anyway with such a long valve!
Then pinch the tyre between thumb and index at the bead from both sides while pushing the valve into the tyre with your other hand. The bead should drop down into the rim. Without (!) tightening the nut on the valve-stem, attach your pump and refill your tyre to low pressure. Take off the chuck of the pump, bounce the wheel several times and check if the bead is properly seated. If not, repeat the operation. Pump to required pressure if it is OK.


"Right" way to store energy from 2 dynamo hubs I just bought a recumbent trike, and plan to do a fair amount of long-distance traveling on it, to the point that a dynamo hub seems like a really good idea.

I was going to put a dynamo hub on one wheel in the front, but I think it would be annoying to have one wheel dragging more than the other, so I'm considering putting a dynamo hub on both front wheels (speed is not a concern to me, but comfort and controllability definitely are).

Ideally, I'd like both dynamos to supply the same storage and electricity delivery system, but with A/C current, directly hooking them up to the same source seems like it would be a bad idea.

Can I just slap some bridge rectifiers on the output cables and hook them into the same input on the storage device?  Do I need to get more clever?  Is this risky at all?

This is going to be difficult. I assume you have a tadpole or delta and you're trying to drive the dynamos off the paired wheels - and not the single (drive) wheel.

Problem 1: Single-Sided Hubs

The problem is that the paired wheels often use single-sided (aka wheelchair) hubs and most dynamos are made with standard hubs that are designed to be supported on both sides. Schmidt SON are (apparently) the rare counterexample that have single-sided custom versions.

Problem 2: Dynamos have a "direction"

Furthermore, dynamos are often built to rotate in one direction. Rotating them the other direction will lead to fiddly bits falling out of them. That's a problem because almost all dynos have the wires coming out one of the sides (usually the drive side) - and that'll mean that for the right side wheel, the wires coming out the right side will be unsupported. So in practicality, having a right-side dyno might be very hard.

Problem 3: Double the Drag

Dynamos have drag even when non-powered. It varies from about 3-5 watts which is negligible especially on a commuter bike, but when you have two of them, you're doubling to 6-10 watts of constant drag, which is felt more on a trike.

Problem 4: Double the Electrical Inefficiency

While you'll have twice as much current, you'll also at least double the amount of power you're losing to inefficiencies. You can rectify both using bridge rectifiers to get DC from AC but you'll lose some voltage (and thus power) going through the bridges. The problem is going around corners or in a circle, one hub will be putting out a higher voltage than the other and the lower voltage one may not be operating at max efficiency depending on your circuitry. The bridge rectifiers will prevent backfeeding but you're increasing the inefficiency of the system.

Solution 1: Use buck-boost circuits to charge Lipos

On my commuter (bicycle), a front dynohub is constantly charging a LiPo whether the lights are on or off. This is because my cheap Sanyo hub has drag regardless of whether it's under load, so I might as well as use the drag. I rectify and then pass it through a buck-boost to charge up a LiPo which then I boost to charge my cellphone when connected. You'll want parallel buck-boost circuits to avoid the problem of unequal power output listed in Problem #4 above.

Solution 2: You're on a trike, forget dynos

You're on a trike and so weight is obviously not important to you (sorry, couldn't resist the dig). So just get a small 10,000 mAh battery pack and/or solar charger and use that. It's better than the constant drag you're imposing.

Solution 3: Get one really high quality dyno

Get just one really high quality Schmidt SON dynamo and put it on the left side paired wheel if possible. Why the left? If you’re in a country where you drive on the left (most the world except UK and Japan) then the road slightly slopes to the right for drainage. You're already needing to constantly turn a bit left to maintain a straight line and the unequal drag on the left will act as a slight trim and be felt less.

The Schmidt SON dynos have been measured to have the lowest amount of drag when unloaded. Peter White says they have a tadpole compatible Schmidt SON for special order. I have no affiliation with PW except for a single order I placed a decade ago.


How does a chainstay length affect a mountain bike performance? (wrt: 26", 650B, 29r) The trade offs for 26" through to 29" with respect to rolling resistance, contact patch, obstacle rollover, etc... have been well discussed. However, it occurs to me that as the rear wheel gets larger the clearance eventually requires the chain stay length to increase to accommodate the wheel.

How does a chainstay length affect a mountain bike performance?

All else being equal, longer chainstays equate to a longer wheelbase, and the rear wheel trailing further behind you. You are correct in your assertion that as wheel size increases so too does chainstay length, though many manufacturers have put considerable effort into minimizing this and as such the increased chainstay length is not directly proportional to increased wheel radius. For example, a 26" and 29" version of the same bike model are unlikely to have an inch and a half discrepancy in chainstay length. That said, there are tradeoffs to be had in chainstay length differences.

As an analogy, think of a drag strip or hill climbing motorcycle vs a standard sport or dirt bike. The first two examples have very elongated swingarms that put the rear tire well behind the rider and dramatically increase the wheelbase. Those long swingarms are great for preventing the bike from looping out and maintaining straight line stability, but neither can turn or corner like the latter standard motorcycle examples. That is a very exaggerated example, but the same principles apply to chainstay length differences on bicycles. Again, all else being equal, longer chainstays are going to be more stable at speed and typically provide better climbing traction, but they will cause the bike to not handle as sharply and to no turn as quickly- that much is just basic physics.

Keep in mind that chainstay length and wheelbase are just two factors in a multitude that determine how a bike will handle. Also keep in mind that just because you have a bike with slightly longer chainstays doesn't mean you can't rail corners or navigate switchbacks, and just because you have shorter chainstays doesn't mean you can't bomb descents- much of this comes down to technique, and you'll alter your technique to accommodate for any differences in your bike's handling characteristics.


Should my fore/aft range be so narrow? I started setting my fore/aft by using the "hands off" method (being able to balance leaning forward with no hands). This occurs with the tip of my seat 8.5 cm behind the BB.  But, at this point, when I get low, in the drops or aero bars, my speed & power drops like a rock.  Moving back to 9 cm, I can get very low, without power loss.  At 9.5 cm, my power drops significantly when I get into an upright position!  (At least I know at what setback I'm the fastest!)  But, does this sound right?  Is it normal to have such a small range -- or, nearly no range, in this case -- in which I can efficiently pedal?  Or, does this indicate a problem with my fit?   (If I raise or lower my seat just 5 mm I also experience a significant loss in speed/power.)  This also makes me wonder how time trialist get in to such a forward position.  If I did that, apparently I'd end up going backwards!  Any ideas?

It is not unusual to have a very small range of position which allows for your most efficient pedaling position.

It is a little unusual for it to be quite that drastic a change. Are you accounting for the change in saddle extension by adjusting your seat height as you move the saddle for and aft?

If not, I expect that it is more the extension length than your fore aft positioning which is affecting you.

By the way, 7-9cm behind the BB center is fairly far back when measuring from saddle tip. Most people are in a 2-5cm range, unless they are unusually tall or have unusually long femurs for their height. You may want a professional to take a look at your fit.

I hope that is helpful.


Changing out suspension forks for non suspension forks My wife has a Marin Bobcat Trai with 'In-Sync 266' suspension forks. She is not convinced they help her in any way so I was wondering if it is possible to change them out for non suspension forks. We are planning a cycle tour that will involve very little, if any, off road trails.

Yes.  This can be done.

There are some important considerations that you should make, however, before the change.  Frames are generally built with a particular amount of travel in mind.  The frame geometry is "optimized" for a fork of that travel.  Adding one with less or more travel can change the geometry, handling, and feel of the bike.  Many rigid fork manufacturers these days make various versions of a fork meant to replace a suspension fork of specific travel and keep frame geometry the same, or as close as possible.  Additionally, the fork will need to have whatever axle spacing and brake setup that you have on the current suspension fork.

All of that before installation, which will generally require some specialized tools to cut the steer tube to the proper/same length and then clean up the cut.   You'll possibly also need some headset parts if the old ones can't be removed from the old fork without damage.  Lastly you'll need to do a headset and brake adjusts after the fork installation.  All of those tasks are relatively simple, but best left to someone who has done it before, or supervised by someone who has done it before.


V-brake to disc brake I want to buy a new fork (a SR Suntour Raidon XC DS-LO-R if you are curious). It says that it works only with a disc brake. Guess who has a V-brake? Me. How to upgrade from V to disc and is it worth it to do it for such a thing. I ride street, light trails and I almost don't jump with the bike.

This can get expensive, so check the costs before committing.

You require a disk brake caliper and lever, which might be a sealed hydraulic unit or a cable-operated one.

The caliper needs to operate on a disk rotor, and the rotor needs to fasten to the disk compatible wheel hub.

It is probably cheaper to buy a new complete disk-compatible wheel rather than rebuild your current rim onto a new disk compatible hub.

Also check the mount on the new fork - if it's for a through-axle then your new wheel needs a through-axle compatible hub. QRs seem to be vanishing.

Depending on your grip condition, you may need to replace them too.  May need to cut the old grip off to swap the brake lever.

Your tyre and tube should transfer over okay, assuming they aren't worn.


Might biking lower forehead temp readings at destination? I often bike to work at a place that screens all who enter for fever. Lately this has been done with a no-touch forehead thing, presumably an IR gadget. When I bike, even if it is cold enough that I wish I'd worn full-finger gloves, the final uphill makes me sweat, yet even so I consistently arrive with my forehead so cool that the gadget gives a number in the 92° Fahrenheit (33°C) range, or more often just refuses to give any number at all. When I make the trip by car, by contrast, it consistently gives more normal readings of 94.7° fahrenheit (35°C)
As a 65-year-old male on a beta blocker, I expect my body to run a little cooler than average, but 92°F (33°C)  or lower for a forehead reading seems extreme. It's as if the biking itself is somehow an additional cooling factor. Could this be? Have others found this, now that "temping in" is grown so common?
I get that evaporative cooling with sweat is peculiarly effective for the cyclist, thanks to the air flow, and that the forehead is a prime site for it; but it hardly seems like that should make the forehead peculiarly cool, since (with apologies to Shakespeare) the blood is hot that must be cooled by this. (By analogy, the fins on a motorcycle engine also exploit air flow for cooling; but one hardly expects them to be cool to the touch after a long uphill has put their cooling capacity to the test.)

The body controls its core temperature, not the skin temperature. Skin temperatures will vary significantly, to the point they are generally considered an unreliable way to measure core temperature, especially for people under heat stress (Riding a bicycle).  (Refer : here)
Screening using such a thermometer is more about the "Security theater" of being seen to do something, but the high incidence of false positives and false negatives make the concept unreliable and falling into the realm of "Theater". (Here)


Tyre pressures and Pumps I have just purchased a new floor bike pump.While checking the tyres on my road bike
the gauge reads for the rear tyre 0.95 bar , 13.5 psi.the reccommended pressure is 130 psi,
maths not being my strong point! Am I just reading it wrong and not moving the decimal point so the actual pressure of the tyre is 9.5 bar and 135 psi.Sorry if this makes me seem a bit thick but I am new to cycling and want to get it right, better safe than sorry and all that.
Thanks.

8.5 or 9bar is a usual maximum recommended pressure for road bike tires (23mm width). Depending on your weight and demands on comfort something between 7 and 8.5bar is usually right. Just be aware that road bike tires lose pressure pretty fast so you have to refill them every week or so.

They should feel very hard at 8bar. If you can pinch them it’s way too little (though it’s hard to gauge pressure by hand).


How many spacers I can put on a Shimano hollowtec 2 BB for a 68 mm BB shell My bottom bracket shell is 68 mm English thread.

I put a 1 mm spacer on the drive side BB to move the chain rings further away from the frame, so to prevent the chain rub against the inside of the front derailleur cage when the chain is on the small front ring and largest rear cog.

I have already adjusted the FD limit screws, there is no way the FD can go any further to the frame.

Before I adding the spacer the rub is very obvious. After adding the spacer the rub is very minor but I want to eliminate it.

Should I　add one more 1 mm spacer on the drive side? I already added another 1 mm spacer on the non-drive side because left crank will rub the kick stand without it. So I already put total of 2 mm spacers on the BB.

Can I add one more on the drive side?

On M542 crank set and 68 mm BB shell, I use one spacer on the left, and 2 on the right.

I think that on 68 mm shells you always use all 3 spacers, and distribute them on the left/right side to get chain line you need.


Questions about tubeless tires I keep getting a lot of pinch flats even though I've pumped my 26x2.00 wheels to 280Kpi (65psi) and I've been thinking about converting to tubeless. But I don't have both tubeless ready tires and rims. What if I buy just the tires but use my current rims, will it work?

Without tubeless ready rims it will be hard to get a traditional tubeless setup to work.

What could possibly work might be a ghetto tubeless setup as described here:
http://www.mtbtechniques.co.uk/MaintananceGhetto.html

Altough this is specific for mountainbikes. On a road bike I would suggest getting proper rims for a tubeless setup.


how long does it take to break in a brooks saddle (b17) I'm going on a 2 week touring trip and looking to buy a comfortable saddle that will be make my rides pleasant and efficient.

I have about a month to break in the saddle.

How long should I spend breaking a brooks b17 before taking it on a touring trip?

Any tips to speed it up?

By breaking in your Brooks B17 etc. leather saddle, you create the "valleys" in the leather for your sitbones and the crotch area of the pelvis bone.

Therefore you need enough time for the leather to deform at these three areas. There is various information on the net. My experience is that about 500km of riding (so about 25h at 20 km/h) gives a good enough break-in.

SITBONE

However, I agree with "Fred the MagicWonder Do", if it is not roughly comfortable on day 1, i.e. roughly the width is not good enough, it never will be.

So from these, the biggest deciding factor of saddle comfort is total effective sitbone width. This is measured in cm, and the width you need depends on two things:

Base width = width of your sitbones (in cm, typically 10-14 cm)
Plus additional width required for your riding position (in cm, typically 0-4 cm)

triathlon +0cm
sporty +1cm
trekking +2 cm
city +3 cm
fully upright +4 cm

If in doubt, go for wider. Narrower causes pain.

You can measure your sitbone length with cardboard paper (like an amazon shipping box).
See the info at SQ Lab for the measurement (you don't need the special device, you can do it on a simple chair).

SQ Lab saddle width measurement

In theory, if the B17 is wide enough for you, after break in, it will be even more comfortable. If it is not wide enough, try Brooks B67.

If I remember well, the max effective sitting width of a Brooks B17 saddle is 12 - 12.5 cm, but you need to check. If your total effective width is above that, you will find it uncomfortable after break in, because your sitbones will be over the metal part of the saddle, where it cannot deform. So what counts for leather saddles is not the total width, but the parts that can deform, inside the metal U-frame. Also, for other saddle brands, this is what you need to check.

The big part of men find comfortable a Brooks B17 width, and these people write in the reviews how comfortable it is. Those who complain, probably have more distance between the sitbones, and/or ride more upright, and the B17 is not wide enough for them.

I have a wider than average sitbone width (12.5 cm), and I ride in a trekking position (14.5 - 15.5 cm), and no surprise, the B17 was uncomfortable for me. The B67 was better. In the end, I decided on a 15 cm SQ Lab 604 saddle, as it is water proof, and I often bike in rain/cold(wet). I don't like that when it rains, I stop, stand on my feet, the leather takes up water, and keeps me wet the whole day.

CROTCH

The other deciding factor is crotch depth - whether there is room for the crotch part of the pelvis bone, or the bone and genitals hit hard plastic/metal.

Anatomic, or leather saddles have/create room for the crotch.
This part of the comfort you cannot feel on the first ride on a leather saddle, only after break in.
It is independent from saddle size.
For 1-2 hour rides, or triathlon positions ("sitting on the legs"), the crotch comfort doesn't matter that much. It matters usually after 50-60 km of ride. When my crotch hurts, I simply cannot ride more. When the saddle is right, my buttocks are tired, but don't hurt, and I can do 100+ km.

As there is less weight on the crotch, and when it hurts, unconsciously you will stand more on your legs, it takes more time for the "crotch-valley" to form in the saddle, maybe double time. At the beginning it hurts, and as time goes by, and as the leather deforms slowly, it will be better and better.

An anatomic saddle, which has the valley for the crotch built-in, only needs some play with angle of the saddle, otherwise it should not hurt from day one.

Note that if you change the angle of the leather saddle after break-in, it can be the the crotch-valley is not deep enough, and it hurts again, until it deforms according to your new position.

Otherwise, here's a link for saddle break in:
Breaking in a Leather Saddle

This is the most imformative page I've found about Brooks saddles:
Leather Saddles - SWHS.home.xs4all.nl


Good beginner workouts on stationary bike After many years of programming, I have found that I can no longer avoid the fact that I spend most of my day sitting, which is absolutely horrible for my health. I started swimming a few months ago and am enjoying getting back into better shape, so I'd like to start adding in some workouts on a stationary bike. I have one long bike tour under my belt, but that was many years ago at this point, so though I'm not new to cycling I haven't ever really focused on cycling for physical fitness.

I have ready access to a boring bike at the gym. It just has flat pedals, but it does have a computer and controllable difficulty levels, along with a built-in pulse monitor. My question is, what sorts of workouts would be good to try for starters ? Should I just get on and pedal for half an hour ? What cadence should I aim for (in my mind I'm shooting for somewhere near 100) ?

I have two goals in adding a stationary bike workout: I'd like to increase my cardiovascular fitness (currently I can barely swim 100m in one go, because my lungs feel like they're going to explode), and I'd like to make my quads stronger. Hopefully these aren't at odds with each other.

How long do you have?  How strong is your motivation?  How good are the bikes?

Unfortunately, most exercise bikes have a very poor "simulated feel", and a real cyclist tires of them pretty quickly.  This is especially true of the old friction bikes and many of the wind and magnetic trainers.  A few (Expresso bikes, and some of the newer Le Monde bikes that I've tried) do have a halfway passable "feel", though, since they have a modicum of momentum (which is the main thing missing in the others).

You can use the bike for several things -- short bursts, to raise your HR and short-term aerobic capacity, long sessions (at LEAST 30 minutes, preferably longer) to tax your glucagon storage just a hair and build endurance, and brief "climbs" to strengthen your muscles.

But, given access to a reasonably well-equipped gym, you probably should throw in some strength training as well, with leg presses, extensions, and curls.  And, believe it or not, simply being conscious to doing more squats through the day (eg, when reaching down to open a file drawer) can produce significant improvement.

And you really need longer sessions -- at least two hours at a crack -- to build your long-term endurance.  These are probably best done on a real bike, though, if at all possible.

I'm not convinced cadence is that important, but as a rough guide I'd say about 110 minus 65% of your age should be the upper limit, and 75% of that number would be the lower limit.  (Unfortunately, many exercise bikes only work smoothly at high cadence.)  My general rule for cadence lower limit is to never pedal slower than you're breathing, and that covers virtually all situations other than a brief climb.

Heart rate is also a guide, but there is much individual variation in rate, so it's hard to give numbers.


Consequences of using smaller replacement pulley/jockey wheels in the rear derailleur I have a new rear derailleur (Microshift Advent X) which uses somewhat oversized cog wheels with 12 and 14 teeth. I am known to wear these wheels during the winter season, so I am already planning for spare parts.
I have a small stash of smaller 11 teeth pulley/jockey wheels and I wonder if I could install them when the time comes, instead of looking for matching larger spares. The benefits are that the 11-teeth parts are quite more widespread, but what are the possible problems that this could create?
Here are some negative things that I can imagine, but maybe I am missing something or underestimating the consequences.

Clearance problems between pulley/jockey wheels, derailleur cage and chain passing through them. I can imagine that squeezing larger cogs could cause that, but with smaller ones the clearance should increase.

Increased chain friction because of sharper angles when links are wrapping smaller cogs. I could not care less about it. The bulk of my friction problems in that area come from clogged bushings/bearings inside the pulley wheels; something that better seals, not more teeth, should help with.

Change of the optimal chain length. I can imagine that with fewer teeth I'd need to remove a few links from the chain? Or is it the other way around, and the chain must grow?

Worse chain retention (chain jumping inside the derailleur). I wonder if this will be noticeable given how constrained the chain inside the cage is, and with clutched derailleur keeping it tensioned.

I am now in position to answer my question, as I've obtained practical results of an experiment described in the question.
I managed to destroy an upper pulley wheel when it met a stub. The rest of the derailleur was undamaged.

The damaged guide pulley had 12 teeth (not 13 teeth as I originally miscounted). I only had 11-teeth replacements from SRAM in my reserves. So I went ahead and replaced it. I also shortened the chain by 2 half-links as I felt it was just a bit too long as well.
The main adjustment that I had to do to make it work was to ensure that the cage would not touch the cassette when climbing from the next-to-biggest cog to the largest cog. The B-tension screw of the derailleur was turned until there was a gap between these parts. A smaller diameter of the replacement part brought the cage closer to the cassette, so that had to be accounted for:

During the next two weeks, the repaired derailleur worked without noticeable differences compared to how it shifted before.
I have just received and installed a replacement 12-teeth upper pulley wheel from the manufacturer (the part is not available aftermarket yet). Again, I have not noticed any difference in shifting.


Importance of a thru-axel for mountain biking Looking at two fairly similar mountain bikes.  On the rear wheel, one of them has a thru-axel and the other one doesn't.  What kind of effect will this have on the bike's handing and how important is this?

Kona Big Honzo has a thru-axel (link):

Norco FLUID 7.2/6.2 HT+ doesn't have a thru-axel (link):

The industry has gone through axle as they do have advantages. The dispute I have with the marketing is how much difference that advantage is. Through axles have advantages only if every thing else is equal. Like most things bikes, quality of construction is more important than style of gadget, so a QR on a quality hub will outperform a Though axle on a lower quality hub.

One reason to go Thru axle is if you think the look is important.

For actual riding, all else being equal, go for the thru axle. But I mean 'equal equal'.  If you have got to the point you are going to flip a coin to decide kind of equal.

Edit:
Advanatges of thru axles

Stiffer - less important on the rear axle, helps with more precise and predictable steering
Stronger - only an advantage if you are in teh habit of breaking axles.
Captured  - cannot be ejected by disk brakes, although problem solved with
lawyer lips

Disadvantages

To remove wheel need to remove axle. Lost axles/axle left behind do occur. Many Axles are propitiatory - lost axle means bike off the road till manufacturer supplied one arrived, days and $$$$.
takes longer to change a wheel - if 10 seconds matter to you, QR may be better
Some need tools to remove and install.

Keep in mind when reading internet about advantages of Thru axles, many reviewers base their description on a new bike (or fork) vs old bike (or fork), and attribute all the change to the through axle. Those that do robust comparisons are professional riders. Most riders will not feel the difference. So in terms of what you have asked - there will be no practical difference between the bikes because of the rear axle.


27 inch tires significantly harder to change than 700c I've got a newer road bike I use for my longer, faster weekend rides (700c tires) and a 70's Sekai that I use to ride with my son, and to run errands (27" tires).

I have no problem changing tires/tubes on the 700c set, but I always have a terrible time changing the 27" set. I usually end up pinch-flatting the tube while trying to wrestle the tire/tube onto the wheel.

Am I doing something wrong? Does anyone else have this problem?

Without looking at your wheel, I will have to guess that it isn't the diameter of the wheel that is causing the problem but rather the rims. Some rims come with deeper channels than others. The 2 example cross sections bellow will show you the difference I am referring to. The rim on the left has a deep channel where the tire bead can sit as you remove the tire from the opposite side of the rim. The rim on the right has a shallow channel where squeezing the tire to the middle does little to help you as you remove the tire.

The purpose for the differences is that the more shallow channel gives you a stronger rim at the expense of making it harder to remove the tire. The deeper channel allows you easier tire removal but compromises the strength of the rim. My front rim is like the one on the right and it is a TOTAL pain in the butt to change tires!!

What I use are the Parks Tools Tire Lever, it takes a lot of abuse but is really gentle on the tires/tubes. It will still pinch if you are not careful. Deflate the tire COMPLETELY, slide everything to one side and lift only one bead of the tire over the lip and hook the lever to a spoke. Keep doing this inch by inch using a new lever each time (there are 3) until that one side of the tire comes off, then pull out only the tube. Getting it back on is about the same, but I use dish soap to lube the tire and rims, helps a lot!


Where can I buy lugs for a classic roadster frame geometry? The title says it all. I want to build my own frame and need lugs that will fit the roadster (e.g. Raleigh Tourist) geometry.

No Roadster lugs are available for the independent or small shop. That is why I had to make them.

Roadster lugs are made [India, China, Taiwan and of course in the Netherlands], it is just that distributors like Nova and Ceeway do not buy them.

I find it amusing about the comment about TIG welding lugs. Why lug anything really...it is just for looks. Stamped lugs are welded together :)  Only the expensive racing lugs are cast.

I think you best bet is to try and find them in India or Taiwan and ask for a sample.


Bicycle trailer that can secure cargo? How do you secure your prior purchases in your trailer when you go into another store to make more purchases?

Unlike in a comment above, I'm not going to assume that you can carry the rest of your shopping when you go in the second shop. But hopefully you can carry any valuable items, then leave cheap bulky stuff in the trailer.

I do this with panniers and backpack, buying the more stealable items first and keeping them with me, then buying fruit and veg, leaving them in an open pannier, then going to the supermarket for the rest of the food shopping. The open pannier is on the basis that a closed pannier could be full of something more tempting than a bag of onions.


DTSwiss rear wheel hub part name I want to buy a used bike (Specialized Tarmac) with good price
But rear wheel hub is broken as in photo

What is a part name I have to buy and change, or it must be completely changed
PS: I don't know exact model name, but on it Ultegra 67xx 11 chains

UPDATE:
The wheelset model DT Swiss Axis 3.0

The part which is broken is called the flange of the hub, however these aren't replaceable. You'd need a whole new hub or wheel.


Failure statistics of carbon fiber vs aluminum mountain bikes? I've read a lot of carbon fiber vs aluminum debates. The anecdotal evidence for one being better than another is not very interesting to me. I'm interested in the statistics.

Does anyone know where I can find actual failure stats for mountain bike frames? How many warranty repairs per year for each type vs sales volume, for example? Anyone work at a bike shop that can share the average number of people coming in per week with broken aluminum vs carbon fiber frames?

I've read a lot of carbon fiber vs aluminum debates.
  Does anyone know where I can find actual failure stats for mountain bike frames? How many warranty repairs per year for each type vs sales volume, for example?

I'm reading this as a strength of materials focused question - carbon vs aluminum.

Summary:
For a properly designed, well made frame on a correctly assembled bicycle ridden in a manner that is not abusive (I know "abusive" is a relative term. A good frame should be over engineered to handle some abuse, say 80% - so I'm talking about the 20%) frame failure for carbon or aluminum is a non-factor.

However, warranty frame repairs/replacements data would be made up of:
- Material failures (that your question refers to)
- Manufacturing failures
- Flat out user abuse (the 20%)
- Incorrect assembly
- Damage during shipping
This statistic would not provide an accurate reflection of the merits of the two materials.

Generating reliable, comparable, standardized statistical data is expensive and tricky. There is no motivation for the bicycle industry to spend the money to generate this information or to share the data they have for many reasons. Frame design / styles change so frequently that even if the data were generated it would be outdated quickly.

We don't have reliable, comparable, standardized statistical data that allow us to compare specific frames or types of frames to each other we do strength of materials data that we can use as an indicator of the merits of the two materials.

Manufacturing Technology for Aerospace Structural Materials
Fig 7.2

  Composites do not corrode and their fatigue resistance is outstanding. Corrosion of aluminum alloys is a major cost, and a constant maintenance problem, for both commercial and military aircraft. The corrosion resistance of composites can result in major savings in supportability costs. The superior fatigue resistance of composites, compared to high strength metals, is shown in Fig. 7.2. As long as reasonable design strain levels are used, fatigue of carbon fiber composites should not be a problem

  The specific strength (strength/density) and specific modulus (modulus/density) of high strength fiber composites, especially carbon, are higher than other comparable aerospace metallic alloys.

From a strength of material perspective carbon is more fatigue resistant and higher strength than aluminum.
The materials are more than adequate to the task.
What matters is:
- Frame design
- Correct frame construction
- Correct assembly of the bicycle

In an ideal world (one without people who would cut corners making bike frames) you should be able to base your decision on the riding qualities of the two materials and your personal preferences.

So, select a trust worthy brand/frame maker and make sure your bike is assembled by a knowledgeable person and base your buying decision on your personal riding preferences.


SRAM Force 22 chainset in an otherwise 10-speed SRAM setup I notice that SRAM web site still lists "regular" 10-speed Force chainset as one of their products. However, my attempts to find it for sale online came up with almost nothing. It seems to be "barely" available at some places, but the chainring/BB/crank length combination I'm interested in (50/34, GXP, 172.5mm) proves to be impossible to find.

Hence the question: what about SRAM Force22 chainsets? Will they work in a 10-speed setup? Specifically, with regular SRAM Force front derailleur and shifter?

If you are prepared to move down to the SRAM Apex model, you can still get a 50/34 172.5mm version http://www.chainreactioncycles.com/au/en/sram-apex-white-gxp-compact-10sp-chainset/rp-prod83674

The first question and answer here indicates that an 11 spped chainring will work with a 10 speed chain: http://velonews.competitor.com/2015/03/bikes-and-tech/technical-faq/technical-faq-10-11-speed-drivetrain-component-compatibility_362722


What are the good ways to maintain the bicycle while raining season? I have a bicycle. I ride it everyday because it was my primary vehicle. When I was going to campus or another places, I used it. Currently, the raining season is on my country.  I would like to keep my bicycle healthy, for example case, preventing a bicycle chains from the corrosion. Also, another use cases which can be happened while raining season.

Any good suggestion for that cases?

Use fenders with good coverage! They will keep most of the dirty spray water off your bike. You'll be surprised how much less oiling your chain needs with proper fenders.

Proper fenders means:

a front fender with a mud flap that reaches within a few centimeters of the road
a rear fender that starts some centimeters below the chain stays, so that water dripping off does not end up on the chain


Advice/Tips for first time racers I have entered a 30km mtb race that will take place in a couple of weeks time. I don't know much about the route and won't be able to get on it beforehand as it goes through private farms that will only be opened for the public during the race.

The profile is as follows:

Does anyone have any tips as far as what a good average speed would be, what a good average time would be and when or when not to go all out? Sprint in the beginning? Sprint in the end?

Any tips would be greatly appreciated.

Don't make any major mechanical changes to your bike the day before the race. If it ain't broke, don't fix it- at least not at the last minute. You will end up kicking yourself for it. Make sure you've had plenty of riding time on your bike's current configuration.
Bring tools and tubes, but pack light. Bring a small/medium sized multi tool, a tube, something to air it up with (preferably co2), tire levers if they're not part of your multi tool, and maybe a patch kit if you have bad luck with flats.
At the gun, go for the hole shot. Most mtb races will start in an open area and give you somewhere around a quarter mile to a couple of miles before singletrack to vie for position. Ending up middle or back of the pack means a lot of clawing your way past slower riders throughout the race which equals lots of lost time. Sprint early and then slowly let off to recover. Don't be the jerk that gets the hole shot then blows up only to be passed by the entire field.
Find your pace and settle in. After the sprint start it's important you recover and don't over pace yourself for the rest of the race. Otherwise you'll find yourself blowing up before the race is over.
Drink before you're thirsty, eat before you're hungry. Words to live by when riding regardless of whether you're racing or not, but especially important when you're racing. Bonking and cramping sucks, so be proactive in avoiding both problems Bring plenty of food and water. Gels are preferable as they're easy to consume when you're running near redline.
Be polite when passing and being passed. When you need to pass, let the person ahead know your intentions and which side you plan to pass on, and wait for a safe place to pass. If someone is asking to pass you and you're not in podium position, let them by at your earliest convenience. Don't let impatience or pride get in your way in either case.
Don't wear headphones, even if the race organizers allow them, unless you plan on leading from the gun to the finish. Don't be that guy. You'll know what I mean the first time you try to pass someone who's jamming out instead of paying attention to the race.
Don't sandbag. This one is for your second race if you blow the field away in your first race. Bump up a class if you embarrassed the competition, because it's shameful to stay in a class just because it's an easy win. Not saying this is you but it's worth getting out there for others.


Due to hip and knee problems I need to fit my saddle a couple of inches further back is there a bracket available? Due to hip and knee problems I would like to move my saddle  up to a couple of inches backward, is there a bracketed seatpost or similar available? Any solution would allow me to ride for longer periods, an answer would be very much appreciated.

There are offset seatpost but I don't know of any that are more than 25mm = 1 inch


How do different types of handlebar tape do in the rain? I'm planning to replace the handlebar tape (nonabsorbent, basic plastic tape with no padding) on my commuter bike, and I was looking to switch to cork tape.  However, I always park it outside and it occasionally rains, so I was wondering if the cork's absorbency would be a problem.  Also, what about leather and other tape types?

There is very little actual cork in most cork tapes. The plastic foam absorbs some water and may become slightly slippery, but it doesn't deteriorate or anything.


Shimano Acera hits spokes. Which screw to turn? I have a Shimano Acera that hits the spokes in first gear (largest rear sprocket.)
I found three screws on the derailleur Which one should I turn, in which direction?
The bike (Specialized Sirius 2.0) is brand new, by the way, I thought I would fix it myself, as dealer service seems very busy atm.

You need to adjust the L-Limit screw - Have a look at this Park Tool guide.
The problem may also be a bent derailleur hanger. Checking and, if needed, fixing this is best done with a specialized tool, and is quick and easy if you have that tool. While it is possible to make the check and repair without the tool, the precision is nowhere near as good.  This Park Tool guide might be helpful
Given that it's a new bike, I would do a sight check for a bent hanger; if obviously bent, send it back to the shop. If not, have a go at adjusting the L-Limit. If it does not all come together easily with smooth shifting and good spoke clearance, get the shop onto it as it could still be a bent hanger. Without the tool, it takes a good eye to spot a small error.


Is it possible to service Specialized Brain suspension systems at home? I like to do all my own work on my bike, and with other forks and shocks I've had, I've been able to find the necessary service manuals and specialty tools to overhaul the systems myself at the end of the season. Now I have a Specialized Epic with front and rear Brain suspension. My local Specialized shop tells me that the only way to get the fork rebuilt is to have the shop send it to Specialized for their elite mechanics to service it.

Has anyone tried servicing these Brain systems on their on? Any resources to point to? Or is it just a hopeless endeavor and I'll forever be tied to swallowing my pride and paying for someone else to work on my bike?

I've serviced the brain on my 2006 sworks stumpy several times over the past few years, mostly because of the crummy turnaround times from spesh, and the fact that it never makes it through more than half a season before losing lockout etc.  And the fact that I'm a mechanical engineer and stupidly tear into anything that breaks thinking I can handle it (half the time I can't).

I have to admit it took me about a year to get good at rebuilding it, the critical thing is you have to make sure there are absolutely NO air bubbles in the system when you refill it.  Air bubbles getting into the hydraulic fluid seems to be what makes them fail.

There are a few threads out there that are helpful, and there's a rockshox monarch repair video that's similar enough to give you some good ideas.  There are also schematics available on the net that are a huge help and also tell you what size o-rings etc you'll need (and make sure you replace them every time, at the least the standard ones which are easy to get from the internet or in my case my friendly neighbourhood hydraulic component shop), they're cheap and if you don't you have a good chance of failure.  Note that some of them are Vitron (teflon impregnated), unless you have absolutely no choice replace vitron with vitron of the same color (durometer).

I had the schematics saved somewhere but haven't found them yet, that's how I ended up here, I'll try to remember to check back once I find them, and if anyone wants let me know and I'll pass them on.

I don't bother with nitrogen, I think the main reason they use it is the convenience of a high pressure cylinder of nitrogen versus using a hand pump or a high pressure compressor (you want to charge the brain side to 350-400psi).  Some shocks do just use air.  I put a schraeder valve on my brain and use a suspension pump to fill it, I can get about 350 psi into it.  If you wanted nitrogen you could probably go to a motorcycle service shop and get them to charge the system for you.

To refill it I have used Fox fluid, but it's just rebranded motorcycle fork fluid marked up about five times as much.  I've used Belray motorcycle fork fluid with success (It's available in a variety of weights so you can experiment a bit, I think I used 7 wt).  I've also tried transmission fluid at someones suggestion, it works fine but smells terrible, I doubt I'll use it again.  Whatever you use you need a lot because you need to have a bath of it you can fully emerge the whole system in while you reassemble to make sure you don't get bubbles, for me I need about a gallon minimum.

There's probably no reason to take apart the shim stack, but if you do be very careful and methodical, take your time and take LOTs of pictures.  If you dont get it back together exactly the way it was it probably won't work, and I've only found shim stack diagrams for one or two models of brain.

Good luck!


How to bend handlebar to customize it? Here in my country is kind of difficult to get certain types of handlebars, but it is easy to get flat and riser mountain type handlebars and standard types of road drop bars.

So I'm investigating whether it is possible to purposefully bend a straight handlebar to have it in another shape.

Can it be done with common store-bought tools? If not, I can take it to a metal working shop and get it bent there? Will it be safe?

In particular, I'd like to turn straight handlebar into a bullhorn shaped one.

I'd like to have this done on aluminum but i'm not sure whether a finished handlebar can be bent.

A second option is to make the handlebar out of steel pipe that is easily bought locally. However to install it on a bike shims will be needed to make up for the "bulge" that handlebars have in the clamp area.

I have currently configured my bike with a short straight handlebar fit with bar ends and it works pretty well for my purposes, but I'd like to have a rounded curve instead of the sharp angle that the bar and bar ends have.

I currently do not have the means to buy a ready-made bullhorn via internet by myself, but if I had, the hassle of shipping, customs taxes and other annoyances made me wonder if making my own is feasible.

No! Don't do it!

Certainly not with aluminium / alloy bars. Any bending stresses the internal structure of the metal, weakening it. Even in a metalworking shop, I would be doubtful of the safety of the product. I hesitated to say final product because the result could be ... final. For you.

Even with steel bars, I wouldn't do it. With steel bars we used to bend them slightly to have our preferred shape. But the wall thickness of steel bars these days is so low that I would not recommend even slight bending. With such low wall thickness almost no amount annealing or other treatment will restore full strength.

The other thing you mention is using plain pipe. Since it's not high-tensile steel (it'll be plain carbon steel), to be strong enough it will have thick walls and be heavy.


Brake lever compatibility Is a V-brake lever (specifically the Avid Speed Dial 5) compatible with a side-pull road brake (specifically the Colnago X brake)? The bike is being converted from track bar (bar-end brake levers) to flat bar.

In general, V brake levers are not compatible with sidepull brakes because of different mechanical advantage. Avid Speed Dials have adjustable mechanical advantage, so you might be able to adjust them for sidepulls.


Does a slightly untrued wheel damage the wheels? My wheels are slightly out of true, about 1.5 mm at worst part. It doesn't bother me when riding and I don't feel it, but will this hurt or damage the wheel if I keep going on, or should I keep going until it starts bothering me?

It won't present any immediate danger, however it became untrue for a reason. If the spoke tension has changed more than likely it will get worse over time and riding it while out of true will most certainly expedite that process. Other spokes will lose their tension and could possibly break resulting in a higher repair bill, or possible injury.

You will not immediately damage the wheel or rim but continuing to ride on it will only make it worse. It will also put stress on other aspects of the bike as well and your braking - if rim brake, will likely be slighty less effective.

All of these would be after a while though, so while there is no immediate danger it will get worse the more you ride. Hitting a curb with poorly tensioned spokes could cause one to "pop"


Why am I breaking Pitlock spring washers so frequently? I'm hoping some pitlock users out there can help me out. I've installed these on a pair of new bikes to add some protection for some expensive wheels. They seem to be a decent deterrent. My problem is that I can't seem to remove them without splitting the thin, notched spring washers that sit beneath the pit nut (and engage its grooves).

I've been super careful to press in on the socket/pit when loosening to try to depress those sprung notches. I've also got the hardware on correctly (nylon washer, etc.).

I've seen no internet trail of failure for these things, so my assumption is that I'm the problem, but I've busted 3 now despite trying pretty hard not to, and I'm still trying to figure out what I'm doing wrong. I've watched Pitlock's YouTube videos of install/removal, and they're pressing the same way I was during removal (thumb on socket, fingers behind stay, squeeze in, and rotate with tool). Doesn't look like they're cranking that hard.

I have installed about the same as they do and explain in the instructions (finger tighten, then 1 to 1 1/2 turns with a lever/tool). I don't think I've overtightened them, and in the last couple of re-installs (with the partially wrecked washers, since replacements haven't arrived yet) I've been erring on the side of a bit looser yet.

I reached out to Pitlock DE about this question specifically (I'm an authorized North American retailer since 2006) and heard this back:

  Regarding the question of your customer about the spring washers, I
  talked to our technicians. The spring washers are wearing parts in
  theory but they shouldn’t break that easily. If you press the key
  firmly into the lock when opening and closing it, the washer should
  really last a long time. We’re in close contact with a lot of
  customers here and seeing their and our own bikes, the washers have
  lasted years with fairly regular mounting and unmounting. The thing
  really is to press the washer down with the key when opening the lock.
  Of course, there can always be an issue with the washer itself.

So while this is a part that is expected to wear over time, the experience you (and the respondents in this post) are seeing is unexpected.

We do offer replacement spring washers on our site, here: https://www.urbanbiketech.com/collections/accessories/products/replacement-lockring

If anyone else is having an issue with unexpectedly high failure rate, please feel free to reach out to me directly (via our contact us page), and I can help rectify the situation with the manufacturer and/or provide an appropriate discount on replacement products.


What are some ways to keep biking when you have a car? I used to ride back and forth from work for 16 mi. every day. I recently bought a car for snow rain and such, but it has killed my drive to get out and bike. I was wondering how other people integrate biking into their life when they also have a car?

I guess you have two main tasks, and they involve preparing your "internal" (psychic, mostly) environment, and you external (domestic, mostly) environment.
About internal environment:

You have to convince yourself, or keep convinced, that you actually LIKE TO, WANT TO and SHOULD ride your bike;
You should think AND feel AND know that riding a lot is wiser than driving a lot. There are innumerable hard facts to support this point of view;
You have to look suspiciously to your car all the time. It is a temptation, and should be a last resort since it is all the time tempting you to succumb so that it can do its harm (this is somewhat metaphorical, but somewhat literal, too).
Resist any eventual harassment from family, friends and neigbours in favor of the so-called car culture. Watch these videos, they are awesome, and can help YOU to "harass" car-cultists!

About external environment:

Biking should be simple, not complicated. Leave your bike close to the exit, and your car keys far away from it. Keep your bike-related belongings close to the bike, and the bike always ready to be ridden.
Don't depend on special preparations for riding. Use fenders, "sofa" saddle and platform pedals if necessary, so that you can use regular clothes.
Have more than one bike if this will make you ride more, even if one of the bikes is just for errands.
Keep fit. The more you ride, the easier it is to take one more ride. The less you ride, the harder it is to be back in the saddle again after a "long" time.
When making long term decisions about your house, your work, and your new purchases, your habits, your schedules, etc., avoid the ones that will put you closer to your car and/or further from your bike.

I guess all this is essentially personal and subjective, but I think this is the general way to handle this issue.
Hope this helps


Have I bought the wrong rear derailleur? I cycled through a plastic bag and it bust my rear derailleur apart. Photo attached. My bike is a Raleigh Equipe road bike, which looks like this: https://www.ecosia.org/images?q=raleigh+equipe+road+bike#id=EFEC15345FC6211574940A99C94FF6014623E79F

I have just bought this replacement rear derailleur: https://www.amazon.co.uk/gp/product/B0044DGH2E/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1  and having received it, I think that it might be a bit too big and chunky.  I also just noticed that amazon said it is for mountain bikes.

I think that rear derailleur capacity is around 24 (it's difficult to properly count).

Have I bought the wrong rear derailleur? If so, how do you find a good one for my bike.  I wouldn't want to spend too far north of £35.

Thanks bike people.  You're all very kind.

The derailleur you bought has a capacity of 43 teeth, so if you need only 24 teeth, you're fine on that count. The fact that it is marketed as being for mountain bikes is not relevant in your case--it only comes into play on bikes that have indexed shifting, which yours does not.

Mount it up, set the high/low limit screws so you can't shift past the inside/outside of your freewheel, set the B screw in back so that the jockey pulley rides a few mm below the gears, and you should be ready to ride.

I'll mention as an aside that if your other drivetrain parts are of similar vintage to your late derailleur that something else could fail at any point, and you may need to budget for a new chain and freewheel (at this age, replace both together to ensure they mesh correctly), and possibly chainrings (for the same reason).


What kind of rear wheel should I get for 10 speed Shimano Cassette? CS-4600 12-30 I have a 10 speed bike, and I bought a new cassette CS-4600 12-30
I am just confused. I'm not sure what kind of rear-wheel I should get for the new cassette that I bought. I am planning to use it mainly for indoor biking/zwifting.
I would really appreciate it if someone can tell me if all 700c wheels with a 'freehub' are compatible with the cassette that I bought.
Also my bike has quick release front, and rear as well.

TLDR: All modern 700c road wheels with a freehub will take a 10 speed cassette.
There is a difference between 10 speed compatible and 11 speed compatible hubs. Road 11 speed drivetrains require a slightly wider freehub, 10 speed cassettes are mounted with a appropriate spacer.
There are older hubs with narrower freehubs that that are only compatible with 7 speed cassettes.
It’s strange that you are asking about fitting a wheel to a cassette. I’m suspicious that you have a ‘classic’ 10 speed with 5 gears on the hub and a double crank. (In more modern terminology ‘speeds’ refers to the number of  sprockets in the rear.) You cannot fit a modern freehub wheel into a frame designed for a 5 speed freewheel hub. Older frames have 120 or 126mm spacing, modern frames 130 or 135mm.


How do so many bicycles end up in the canals of Amsterdam? I heard this peculiar story about 20,000 bicycles are fished from the canals.

Found a video that show how its fished out

It's tragic, why can't they be recycled?

Why do you think they aren't recycled? EU legislation is pretty strict on what can go in landfill and it would be very surprising if the bikes fished out of the canals aren't recycled (i.e., melted down and the metal used for something new). 20,000 bikes is going to be at least 200 tons of scrap metal.

After being underwater for a while, the bikes are probably sufficiently badly damaged that their parts can't be re-used: components such as bearings would probably be damaged beyond economical repair and structural components such as the frame and wheels would have corroded to an unknown amount and can't be guaranteed to be safe.


What are the advantages of the Burley hitch design? Burley uses a polymer hitch (the black plastic) which allows some degree of movement between the trailer and bike:

Most inexpensive trailers use a spring to provide that flexibility:

I've only used the cheap spring hitches which can easily absorb the twists involved when the bike falls over or the trailer flips (don't ask). I wonder what would have happened with a Burley. It seems the polymer would have broken.  Are the Burley hitches stronger than they seem and do they have advantages over the simpler spring design?

The spring hitches seem to be a cheap/simple way to allow the flexibility needed to both bend and twist when the tow bike corners, but they have an annoying side effect. In my experience when accelerating hard on a bike with a loaded trailer connected by a spring hitch you can feel the spring stretch with each hard pedal pulse then snap back in to place with a bump.

So Burley might have this new design to eliminate this bouncing effect.

Chariot/Thule hitches don't use a spring, they use both a ball joint and a flex polymer arm which makes them feel a lot better.  Their ball joint rotates easily for normal cornering and leaning, and the stiff polymer doesn't normally flex or stretch noticeably but can bend in extreme situations as a kind of 'fuse' to save the aluminium arm from breaking and/or the bike frame.


How to estimate the speed of cyclist with given parameters How is the speed of the cyclist determined?
If I know the effort of pedaling in watts, the air drag area in meters squared, the rolling resistance details of the tires, and the mass of the cyclist and bike, and the grade of the hill, and the amount of headwind, how can I determine the speed of the cyclist?

The cyclist has three main opposing forces, if riding at a steady speed:

The air drag is determined from 0.5*rho*v*(v+w)^2*CdA where rho is the air density in kg/m3, v is the speed in m/s, w is the headwind in m/s, and CdA is the drag area in m2.

The rolling resistance is determined from m*g*v*crr where m is the mass of cyclist and bike in kg, g is 9.81 m/s2, v is the speed in m/s, and crr is the coefficient of rolling resistance (usually between 0.003 and 0.02 with slick tires having low values and knobby tires having high values, pressure also affects the rolling resistance -- with higher pressure the rolling resistance is lower)

The hill resistance is determined from m*g*v*grade where grade is the grade of the hill (example: 0.05 for 5% hill) and m, g and v are defined as previously.

The terms (2) and (3) can be combined to m*g*v*(crr + grade), demonstrating that rolling resistance of tires is equivalent to always going up a small incline.
How to numerically calculate v using GNU Octave (might also work in Matlab but haven't tested):
m = 70+15; % 70 kg rider, 15 kg bike
g = 9.81; % gravity at surface of Earth
mrr = 42.5; % mass at which rolling resistance is measured
vrr = 29/3.6; % speed of rolling resistance measurement in km/h -> m/s
Prr_GP5000 = 10.3; % Conti GP 5000, 28-622, butyl 130gr tube, watts
crr_GP5000 = Prr_GP5000/(mrr*g*vrr);
Prr_gatorskin = 20.2; % Conti UltraGatorSkin, watts
crr_gatorskin = Prr_gatorskin/(mrr*g*vrr);
CdA = 0.4; % road bike, touring position, Cd*A in meters squared
rho = 1.2; % air density, kg/m3
P = 150; % power of cyclist in watts
grade = 0; % grade of hill, example: 0.05 for 5% hill
w = 0/3.6; % wind in km/h -> m/s, positive headwind, negative tailwind
v_GP5000 = fsolve(@(v)(0.5*rho*v*(v+w)^2*CdA + m*g*v*(crr_GP5000+grade) - P), 9)*3.6
v_gatorskin = fsolve(@(v)(0.5*rho*v*(v+w)^2*CdA + m*g*v*(crr_gatorskin+grade) - P), 9)*3.6

Running the code should show that 70 kg rider + 15 kg bike, at a power of 150 watts, at a temperature around 20 degrees Celsius where air density is 1.2 kg/m3, and a touring position with 0.4 m2 air drag area gives speed of 29.285 km/h for Continental Grand Prix 5000 tires and 27.856 km/h for Continental UltraGatorSkin tires.
The data for the example tires was obtained from https://www.bicyclerollingresistance.com/