Red light facing forwards? I was criticized for having a blinking red light facing forwards on my handlebars (in addition to a White headlight). What is wrong with this? It was nighttime in Manhattan. Isn't more always better when it comes to being seen?

THANK YOU FOR THE ANSWERS, my mistake has been corrected. Best wishes to you all.

No. You should always ride with a white light facing forward and a red light facing backwards. If you want additional illumination, you can add multiple white/red lights in the appropriate direction. Amber/yellow lights can be used facing any direction for additional visibility.

The first reason is that it's the law:

  (a) Every bicycle when in use during the period from one-half hour after sunset to one-half hour before sunrise shall be equipped with a lamp on the front which shall emit a white light visible during hours of darkness from a distance of at least five hundred feet to the front and with a red or amber light visible to the rear for three hundred feet. Effective July first, nineteen hundred seventy-six, at least one of these lights shall be visible for two hundred feet from each side.

More importantly for your safety though, the color of a light conveys a certain meaning. Drivers, pedestrians, and other cyclists associate the color red with a taillight and the color white with a headlight. If you put the wrong color facing the wrong direction, people may think you are traveling the opposite direction. Imagine a car is pulling out of a driveway and sees a red bike light flashing to their left. They may assume that means a bike is moving away from them on the left. If they then pull out of the driveway and you're really moving towards them, you could get hit.


Cycled through pothole on carbon frame - damaged? Yesterday while out on my daily exercise (I live in London) I had to cycle through a pothole (bus too close behind so couldn't swerve or stop) that jolted the whole bike.  I then noticed a rattling sound from the bike on the rest of the ride, although it seemed to be handling normally (gears, steering, brakes). Nothing is obviously loose. Given that there aren't any open cycle shops near us, is there any way to check what is damaged on the bike with limited tools and experience?  Will it be safe to continue cycling on?  The bike is a Trek Domane SL 5 2019.

CFC frames are not as fragile as many people seem to think they are. If you got a heavy jolt but didn't feel like you were going to be thrown off the frame is probably fine. I'd be more immediately concerned about the wheels than the frame, and that may be the source of the rattle.

You can examine the frame closely looking for cracks. If it's dirty clean it first. Using a bright light will help.

Is the rattle coming from the drive train? Does it happen when pedalling only? Does it happen when coasting? Or does it happen when you go over a bump and seems to be something loose on the bike? If the latter, a good way to track it down is to pick the bike up and bounce it on the ground fairly hard on it's tires. By carefully listening you can track the noise down. Trying to locate a source of a rattling noise is almost impossible when actually riding.

Check your wheels are running true. Check spoke tension by systematically going around the wheel pinching pairs of spokes. You may have a spoke broken at the nipple end that is hanging on in the rim.

It's a good idea to learn some bump-mitigation techniques. for smaller bumps raise your butt off of the seat, keep your knees bent and absorb some of the impact. For bigger bumps it's useful to know how to pull off even a small bunny-hop.


Looking for an alternative to the Speedlifter Twist / quickly rotate handlebars solution I'm looking for an alternative to the Speedlifter Twist: http://www.speedlifter.com/twist.php?L=en

The only function I'm interested in is the parking feature where I can turn my handlebar 90˚. I have a small apartment and it would really save a lot of space. I know of the flipphandle (http://www.bikesnapp.com/flipphandle.shtml), but it doesn't appear that the company ever actually put it into production. Has anyone seen anything affordable with similar functionality?

There is the n'lock: Nlock. Which appears to be in production and come in a variety of sizes to fit different bars.  I have no actual experience with them but it looks like it meets the requirements you set out.


Frame and Fork compatibility - 1 1/4" to 1 1/2" I've bought a new frame being this one: https://www.bike-discount.de/en/buy/cube-axial-wls-pro-frame-black-n-green-643919

  Headtube diameter: Tapered 1 1/8" - 1 1/4" semi-integrated ZS44 - full-intgrated IS47  (Cube Headset FSA Orbit Z-t Eco #10359)

I already have a fork from another bike which is 1 1/8" to 1 1/2"

I wonder how can I mount this fork on the frame, since the fork is larger than the bottom part of the frame, I think that something like this could do, but I'm unsure:

Hope brand - Lower Cup Semi Integrated 1 1/2" black

If that's not going to fit, which options do I have?

Thanks, any help is appreciated!

While there are options for mounting a smaller fork in a larger headtube, they're rare, weird and expensive.

For the opposite - The only way to mount a larger fork steerer in a smaller head tube is swap frame or fork, or replace the steerer on the fork.  Either will have costs.

Sounds like you need to find a fork that will fit your frame. Sorry.


What do the numbers on the mantle mean? I've just removed the mantle of my back tire as it has a hole (probably cut by glass). I wanted to look for a new one, but then I realized that I'm not even certain which size it is.

So I looked on the old mantle and found more numbers than I thought:

vtech EAGLE 42-622 700x42C <MDS> (Max durability System)

700 - 42 (42-622)

NL F024   17

I guess vtech EAGLE is the brand / model name, MDS is just some advertisment. But what do the numbers mean?

(Side question: Living in Germany and biking mainly / only in the city, where and for which mantle should I look?)

I think I just found the answer from https://commons.wikimedia.org/wiki/File:Reifengr%C3%B6%C3%9Fen-beim-Fahrrad.png:

So:

The diameter at the outer is 700mm,
it is 42mm wide at the outer,
622mm is the inner diameter


Di2 not responding troubleshooting My bike was on the trainer for a couple weeks.

One morning, Di2 stopped responding.

No shifting
No light at junction box at all
charger doesn't light up orange when plugged in
etube doesn't detect anything.

Tried different battery, same issue.

Tried different A junction box, same issue.

Tried plugging the battery straight to the A junction box with the charger only, no activity either.

I'm running out of ideas!

Let me know if you have a potential solution.

Cheers

EDIT :
I'm suspecting the charger not working and the batteries being flat.
No lights showing on the charger at any time and not detected by my laptop when I plug it in.

I've borrowed a charger from a bike shop nearby and it was my charger that was dead.

Not sure how the battery drained itself completely in the first place but I charged the system and it came back to life.

Underneath the charger, there is the production date and mine was from 04/2013 so it's quite old and could have just died.


Can you identify this freehub from a 2014 Boardman CX Comp? I need to replace this freehub from my 2014 Boardman CX Comp as it's becoming incredibly sticky.
There's not a lot to identify it. It's stamped 'M M P' on the side. Trial and error has found an 11mm hex key to fit the the central spline to remove it. It's a 9-speed cassette.
I expect it's some kind of generic, relatively cheap hub but don't know enough about such things to identify a suitable replacement.

I made a guess. it turned out correct:
Trek/Bontrager (Select) Freehub Body 561948 (repl W268886)
Available from Pedalon (where I ordered from) or GB Cycles (from whose catalogue I figured it out).
GB Cycles listed a few similar alternatives but they can be discounted:

561949 is 11-speed (although worryingly listed a 130mm OLD, whereas my bike is 135mm OLD - but there are no sizes on the 561948)
W268886 has been superseded by the 561948
W211339 has sealed cartridge bearings

I'm still waiting for Boardman to come up with an actual part number or Halfords reference, although it's a moot point now.
I've only actually done a quick test fitting tonight, but the freehub fits the existing hub and the cassette fits on the freehub, so I think I'm good.
Not a direct answer, but I called up Boardman. Not entirely surprised they didn't have a part number, but they were able to offer up a reference with which I could order from Halfords. They have me the usual runaround, but hopefully should have something that fits middle of next week. In the meantime I guess I'll continue getting fat.

Boardman's reference on Halford's system: 341740
Receipt description: "FHB CB/Car/VD Splin F th"
Cost: £19.99

Except it turns out that doesn't fit. Different gender. Drat.


Campagnolo: Can I run an 11 speed chain on my 10 speed chainrings? I have a bike with 10 speed front derailleur and chainrings.
The cassette, rear derailleur and shifter will all be 11 speed.
Can I run an 11 speed chain on this? Everything is Campagnolo.
Thanks

Very likely yes this will work fine.  The main risks are

that it is "out of spec" by the manufacturer so a warranty claim might be rejected
11 speed chain is narrower than 10 speed so the FD's cage will be a little wider - meaning the shifter has to move a little more to nudge the chain over
the tolerance changes can increase the risk of a dropped chain on the inside, between, or outside of the chainrings.

Though I've successfully used 9 speed chain on what started as a 5 speed triple chainset, and its still working fine (though its friction shifting which may disguise some shifting issues.)


Is my daily bike route enough exercise for a 60 year old? Thank you for letting me join your group. I have a beach cruiser and I am currently riding 2,5 mies a day at a rate of about 13 mph constant with no stops. I am 60 years old and have been doing this for about a month is this enough?

I think it is enough for now, what I don't know is when should I increase or should I increase my distance. I have osteoarthritis and I take fish oil for that sometimes my knees hurt. Th distance I am riding now doesn't seem to irritate my knees.

Enough for a little expertise - yes, enough to train for a 100 mile ride, no.

If you are just looking for some healthy exercise you can gradually increase distance and/or speed and back off if you over exert yourself.

If you are unused to exercise or are not currently in great shape, you should consult a doctor before trying anything significantly harder than you are doing now.


BB spindle length standard for single speed bike? Is there a common spindle length for typical fixie/single speed bikes? Namely a bike with:

a 68 mm BSA bottom bracket shell
a square taper bottom bracket cartridge bearing
120 mm dropout distance
single chainring and single freewheel/fixed cog (flip-flop)
a wide single speed chain
fairly recent (2010+) cheap steel frame bike (sold expensively for being hip)

This question would be hopeless for bikes with doubles and derraileurs. However the considerable limitations on fixie chain lines might also have lead to a de-facto standard or a common spindle length most bikes share. The latter in particular, as these bikes appear to be standard mass-products that merely differ by colour, brand, and price tag.

There is no 1 standard square tapered bottom bracket axle length for track frames.
The crankset dictates the bb axle length, it's not as varied as with crankset with gears, but there is more than one.
The range is much smaller than with gears, track bb axle lengths mostly go from 103mm - 112mm (there are smaller and longer for less common cranksets).
I think 103mm and 107mm are the most common sizes, given that their respective cranksets would be the most common cranksets. Although, this doesn't mean that there aren't plenty of others.
Examples:

Factory5 Pista Lattice Chainset - 103mm
Stronglight Track 2000 Chainset - 107mm
Sugino SG75 Bottom Bracket - 109mm
Campagnolo Record Pista Bottom Bracket  - 111mm

There are many more examples, but I verified these by using the Velodrome.shop website.


Is there a way to estimate contact patch size given tire size plus tire volume and rider weight? Is there a way to estimate contact patch size given tire size plus tire volume and rider weight?

Specifically, I've tried to build a unicycle that maximizes contact patch for riding on soft snow. I have a 26"x3.7" tire with a 65mm rim that I have at 12psi, how can I calculate the resulting contact patch?

For extra credit, I'd like to calculate the contact patch size required to ride across newly fallen snow for a particular rider weight.

This question was previously asked as a comment on my previous question, but I feel it needs its own question...

Basically: weight/psi = square inches.

Has to be combined weight of rider and cycle. And it's approximate. And much easier with a unicyle: with a bicycle you need to know weight distribution, which can change during a ride.

Minor things that make it only an estimate:

Compression from weight increases psi, making contact patch smaller than estimate.
thickness of material could increase contact patch size. In fact, I think this math gives you the area of the part of the interior surface of the inner tube that's pressed against the part of the tire pressed against the ground
stiffness of tire materials could decrease contact patch size
tread features (knobs, grooves, etc) could do all sorts of things to contact patch size.
bumps, jumps, etc momentarily increase "weight" (downward force on wheel or upward force on contact patch), contact patch size and psi.

No idea about new fallen snow.


Can I fit 28mm tires on this bike? It’s a Jamis Ventura Comp : https://www.bikepedia.com/QuickBike/BikeSpecs.aspx?item=23765
Thanks!

Maybe.
Given your link, it came with 23mm tyres.  You may still have that size, read the side wall to confirm.  If your current tyres are a different size, then this example will be off.
A 23mm tyre is about 23mm wide, and a 28 is.... 28.  There is some variance on size because of rim width.  So ideally you would use a vernier caliper to measure the maximal width of your tyre, when on the rim and inflated to the highest pressure you would typically use.  Lets assume they measure out at the nominal size.
Your planned 28mm tyre is 5mm larger than a 23mm, so it will use 2.5mm more in width on each side and about 5mm more in height.  The height is on one side because the rim doesn't move, whereas the width change is on both sides of the center line.
With your wheels and 23mm tyres in the bike, find something that is 2.5mm thick.  A hex driver/allen key is a good candidate, or a sliver of wood like a chopstick, or some plastic of that thickness is good too.
Feed this feeler-gauge around your bike frame.  Specific pinch points to check are

Chainstays, both sides
Seat stays, both sides
Fork tines/legs, both sides
Mudguard/fender stays, both sides

Now double over your feeler gauge so its 5mm thick, and check

Rear brake caliper, underside
Brake bridge over the rear wheel, underside
Front brake caliper, underside
Fork crown, underside

If your feeler fits everywhere, then a 28mm tyre will "fit"
HOWEVER a close tolerance is not necessarily good - you do need additional space for dirt/mud, and simple flex while riding.  I would recommend an additional 2mm as a bare minimum.
I have a 90s Cannondale which really should have a max of 25mm tyres.  I have a 28mm in the rear, but refitting it after a puncture means a 3-handed dance between the QR, the rear brake lever, and pushing on the rim at the chainstay to get it all centered.   Otherwise the bike will subtly rub and erode my wheel and left chainstay over time.
Also, if you have rim brakes then a wider tyre can be difficult to fit when inflated.  That same bike has problems getting the tyre through a 105 rear brake caliper even with the brake's QR opened.  It's easier to inflate the tyre with the wheel re-installed.


Where do you leave your bike on cafe stops and water breaks? Where should I leave my bike on longer rides when stopping at a cafe or going into a store to get water?  Do you carry a lock in your jersey? Leave it outside?  What is a good lock?  What should I do so my bike doesn't get stolen?

There is such a range of answers.

A lock mounted to the bike is going to be more comfortable.

A decent light ulock is going to be 1.5 lbs.

A cable lock is going to be more like 0.5 lbs, but not as strong.
But, for a quick in and out it that may be the best trade off.

The weight of the bike plus the weight of the lock to protect the bike is typically a wash.

In a group you could have one lock and a cable, or just have one person at a time stay out with the bikes.  Alternately, you could just have the cheapest bike in the group.

Some establishments may let you bring the bike in.

If you can see the door then you can remove a wheel and bring it with you. I will loop my helmet through the rear wheel. Not much but you pick 5 seconds. You can run down someone carrying a bike.


Is there a distinct look for contaminated disc brake pads? I have sintered pads and I'm trying as best as I can to diagnose a braking issue. I have Shimano XT M8000 callipers and the rear brake is being something of a pain.

If I leave the bike for about 4 days I lose almost all braking power. As I try and figure this out it would be good to know if there's anything distinct I can see or do to figure out whether ultimately the pads have been compromised.

This brake system uses mineral oil so I'd be looking for tell-tale signs of that or other lubricants. Is road grime a possibility too I wonder?

This issue is driving me crazy and I'm trying to find out if there are any leaks in the system through various methods.

Edit
My issue seems to be akin to the one discussed on this thread. http://forums.mtbr.com/brake-time/xt-xtr-brakes-get-squeal-power-loss-after-sitting-idle-6-8-weeks-902792.html

My bike loses braking effectiveness when it sits idle. Quite an odd thing as I'd expect little to no pressure in the system to cause much leaking and surely something should be visible if it is leaking.

Edit 2 to document some fix attempts and diagnosis lines I've been down.

Firstly I manage to get power back by cleaning the pads with IPA and heating them with a gas flame as is mentioned in the comments below.

I've had the bike in the work stand and had a good look for any bubbles around the pots both with a brake bleed block in and with nothing (even pads) in. Bone dry.

I've wiped inside the calliper to see if anywhere is still damp to no avail.

I've visually checked the crimping around the hose and the banjo bolt but there's nothing that indicates build up from sticking to moisture.

Until today I was testing this with just one set of pads. Now there's a chance that my fixes are only good as a temporary measure whilst the bike is being used daily. After sitting maybe some of the contaminants are coming to the surface again. It could also be a build-up of silt from the ride along the canal towpath but I would have expected that to affect me overnight too and not after 3-4 days.

I took the pads out and let them dry for the whole work day one day this week and wiped them with a dry tissue and this did nothing to fix the symptoms.

I changed the rotors front and back although this only affects the rear brake.

I video'd the pots moving with no pads in just in case I could see something when Ina big screen. Not found anything so far. Might need to try it again with a bleed block in for resistance.

I'll add more if I think of anything else I've done.

I had the same problem with my Magura MT5 4-piston brakes. Since I am using sintered brake pads, I literally "torched the hell out of 'em".
I first soaked them in IPA (Rubbing alcohol >70% ABV). After placing them on a surface that won't be damaged by direct contact with fire, like a steel tray or even a brick, I lit the alcohol-soaked brake pads and watched as they burnt until the alcohol was totally burnt away.
Then using a medium-fine sandpaper (in this instance 240-grit) I sanded off the superficial layer of material leaving a lighter colored layer of braking surface. The oil has been totally burnt off. This will not work for organic/resin or semi-metallic brake pads. These variants do not deal with such extreme heat as well as sintered pads. It will ruin them.
I then cleaned the caliper with a pressure washer from a distance of about a foot-and-a-half, occasionally dousing with a highly concentrated Dawn solution like 50:50 water and soap. Only a small amount is needed (an ounce [30ml] or so). Using a fine pipe cleaner will help get any contaminants out of the caliper too. This prevents any contamination in the near future.
I then pressure washed my rotors too. After doing this, I soaked a coarse cotton cloth, like an old towel, in the alcohol solution and scrubbed my rotors free of any contaminants. It's amazing how much gunk is hiding invisibly on your rotors.
I then reassembled everything and bedded in my pads and discs. This is very important as you've removed all of the bedding from the pads and discs during the cleaning process. This is what I did to salvage my brakes from an, otherwise, dangerous contamination of my brakes. Hope it helps you.


Is this change normal? I have recently had my tyres on my bike changed from mountain bike tyres to road tyres. I was also advised by the man who fixed it that my saddle was too low for me and he raised it. Since these changes it almost feels like I am cycling with slightly flat tyres. Uphill doesn't feel massively strenuous but I just wanted to see if this is normal or not?

Re: your saddle being too low.

One way to check if it's at the correct height is to sit on your seat, put one foot on the pedal and try to "straighten" your leg - with the pedal at it's lowest point (the other being at the top) there should be a slight bend to your leg.

This video's quite informative: seat height


Is a long distance ride by an Amateur possible? I am new to biking beyond what I did every day as a kid/teen, and I realize this is a very serious undertaking. I am in shape but not for a ride like this, so I will train. I have a new bike, a hybrid, and don't know much about bikes other than how to take the tires off. I want to ride with a camelback and the basic of basics.

Is this just ridiculous or can I do this by August 2016? What would you recommend to begin? I am female, healthy but with a heart murmur. I would be going at a moderate pace, time is not an issue. Bike from Toronto to Florida, Fly home from Florida.

Edit: Thank you for all your input! I will be seriously considering all of these points. It's a great community here, I really appreciate this!

Is it very ambitious? Yes! Can it be done? Yes!

To make it work, you are going to have to invest practically all your free time preparing, as you have a lot to do.

Bike Maintenance

You are going to want to learn the basics of bike maintenance.

Fixing punctures
Adjusting gears
Changing brake pads
Repairing a chain

Logistics

You said you want to take just the basics, but do you know what yet?  Can you fit it all in a camelback?  And if so, do you want all that weight to be carried by your body each day?  Would some bikepacking gear (apidura/revelate etc) make your trip more enjoyable?

Spare pair(s) of padded shorts?
Spare cycling jersey?
Spare socks/gloves
Warm layers
Windproof/Waterproof layers
Off the bike clothing?
Repair kit
Basic first aid kit?
Toiletries?

Navigation

How are you planning to navigate?

Maps or a GPS?
If its a GPS, how are you going to charge it?
GPS powered by AA batteries so they can be replaced?
If its maps, where will you store them?

Sleep

Are you going to stop for the night at Hotels/B&B's?
If so are you going to book in advance?
What will you do if you don't book and everywhere is full?
Or will you camp with a lightweight sleeping bag and tent?
If so, where will you put those on the bike?

Training

How much distance/how many hours will you cover each day?
How does how far you can ride now compare?
Can you recover well enough to do it again the next day?
You'll need to put in a few days as long as you are planning on your trip to ensure you are not getting sore neck/shoulders/hands/back/bottom.

Fuel/Nutrition

How are you planning to fuel?  You'll need to figure this out too and incorporate it into your training to find out how your body responds.

On the bike food?
Energy drinks?
Cafe stops?

Once you have answered all these questions, and you have put the hours in on the bike, then you are ready for what will surely be an amazing adventure.


Is it imperative to shift to a higher gear when in a descent? I've noticed that, when I'm descending quickly on my road bike without pedaling, the pedals will sometimes spin too much freely, which seems like they have no impact whatsoever on the wheels.

Is it imperative to switch to a higher gear on the cassette in this case, or is this problem caused by failing mechanism in the bike (e.g. freehub)?

No, the behaviour you're observing doesn't mean there's anything wrong with your bike.  You're just travelling faster than you can pedal in a particular gear.

For a moment, let's forget about descending and suppose that you're travelling on a level road, so the only thing that's pushing you forward is your pedalling.  In principle, you can travel at any speed in any gear, as long as you can pedal fast enough.  In reality, of course, there's a limit to how fast you can spin the pedals: your legs can only move so fast.

Now, think about what happens if you stop pedalling while you're moving forwards: the bike starts to freewheel. In fact, this will happen whenever you're pedalling slower than the bike is moving. You can try this out. As you're cycling along, pedal slower for a moment, and you'll notice two things: first, you'll hear the clicks of the freewheel as the bike coasts; second, pedalling is very easy because all you're doing is turning the cranks, chainrings, chain and rear cassette. None of your effort is going into moving the bike forwards.

This is exactly what's happening while you're descending: you're not pedalling fast enough to match the actual speed of your bike, so you're still coasting and the pedals are very easy to turn.

This is a perfectly normal situation: there's nothing wrong with the bike and you don't have to do anything about it.  However, even if you're freewheeling down a descent, I would recommend that you change into a gear that's appropriate for the speed you're travelling at, or your highest gear if you don't have a gear high enough. At some point, you will want to pedal again, either because you slowed down (corner, traffic, lesser gradient, bottom of the hill, etc.) or just because you want to go faster. If you're in an appropriate gear, you can just pedal and drive the bike forward. If you're in too low a gear, the pedals will spin with no resistance, which can be a huge surprise that throws you off-balance and causes a crash. Correspondingly, when you do start to pedal again, always start somewhat tentatively to make sure your gear is appropriate.  It's when you push hard against no resistance that you're thrown off balance.


Road bike's Crank & Cassette on a MTB, what's the catch? MTB's cranks usually have a 42 or 44T where as Road bikes range up to 53T.

So far I am under a impression that more tooth, means more speed. Same goes for cassettes, lesser the tooth more the speed.

But, nothing is as it seems, I want to know what are bad things I expect when I take this move? Is it that bad, that it would be simply better to forget about it and move on?

My main intention is to create a super fast MTB, where possible.

  Please Note: I am not a expert on crank & cassette

There are several things to consider:

Chain ring clearance to the frame, because a larger tooth count has a larger diameter. Since the chain stay is at an angle, and designed for a certain diameter, too large a ring will come too close to the frame. Anything closer than 5 mm, is not a good idea, since a larger chain ring will also flex more.
Maximum tooth count for front derailleur. A front derailleur is designed to work and shift well with a certain size of ring. There is usually a small range above that which can be used. (i.e. Shimano's 3x XT FD-M785 is designed for a 44t, but can accept up to 48t.)
Cable pull ratio for front shifter/Chainring spacing

There are special shifters designed to allow a road bike drive train to run with a flat bar brake and shifter. But there is no easy and guaranteed way to run a road crank set with a mountain bike drive train, unless you replace all of the drive train parts, and buy road touring flat bar shifters.

It is usually more cost effective to buy a road bike.


Chainring compatibility I need to change my chainring(s) and am interested to know what the things to pay attention to are. The ones that are clear to me are:

the number of holes for the crank
bolt circle diameter
distance between the bolts

as somebody that has never done it, I'd think this would be enough, yet I have found some in a shop where the compatibility is explicitly stated to my cranks, but also some where the measurements are the same, and my cranks are not in the list of compatible ones. Is the list just incomplete or inaccurate, or are there also different factors to pay attention to?

For now I will buy some where the compatibility is explicitly stated, but would like to know more in general.

Unfortunately chainring compatibility can be a bit more complicated than number of bolts, BCD and pattern.

Higher end cranks such as Shimano Dura Ace or Ultegra have rings that are shaped to blend into the crank body. Those cranks are only compatible with the rings specifically made for them.

Some cranks may also require rings where the mounting points are offset laterally from the plane of the circle of teeth.


My crank fell off, how do I re-attach it? I was out riding on my mountain bike when my crank unexpectedly fell off (video).

How do I reattach the crank? There's a torque range specified (25-30 Ft-Lbs):

how critical is this? I don't own a torque wrench, if I use an allen key and just guess am I likely to either apply to much force and break something or apply to little force and have the crank work loose again?

In general, crank fixing bolts need A LOT of torque.  This chart list torques for several varieties of crank arms.  (I suspect you have a variety of Octalink.)  You're probably looking at something in the neighborhood of 350 inch pounds, which would be 35 pounds applied to a 10-inch lever arm.

Too much force and you shear the bolt.  Too little force and the arm works loose again.

The torque spec embossed on the bottom bracket cup is most certainly for the cup, not the crank arm.

Unfortunately, if your crank arm fell off I suspect it's been damaged, and is apt to no longer fit tightly, no matter how tight the bolt.


replacing a Trek 4300 bottom bracket with a new one is it possible to put a bb with hallow tech on this bike can the square tapered BB be replaced with one that i can use my two piece crankset with?

The new bottom bracket will fit as long as it is of the same thread and type. The Trek uses an English thread bearing. Shimano also says that you must use a mountain bottom bracket with a mountain crank. The new crank must be pretty close to the same tooth count as the original. The front derailleur is designed to work with a limited range of ring gears. If you are in the 40-44 tooth range you will be fine with the original derailleur. It may require some adjusting as the chain line most likely will be slightly different. I recently did a similar swap and I had to move around  the bearing spacers to adjust the chain line.


Best type of bike lock (materials, style, etc.) I recently lost the keys to my lock and had to borrow a bolt cutter to free my bike. It was a bit of an eye opener to realise a) just how easy it was for the bolt cutters to cut through my D Lock (<10 seconds), and b) that nobody on a busy town shopping street batted an eyelid at me doing so.

When choosing a new lock, what should I look for in terms of build material or design that would make it harder to cut through (using relatively small/discrete bolt cutters)?

Get the kryptonite fahgettaboutit - as small as possible.  Kryptonite 997986 18mm New York Fahgettaboudit U-Lock,Black Mini

Best lock out there. Because the shackle is 18mm thick, I don't think you could cut it with bolt cutters, so you would need a hydraulic jack -- but the opening is too small for a jack to get through -- that's the main reason to go for a smaller lock, so there is no room for the jack; or, a disc grinder to get thru it.


Rear wheel won't stay in position I'm a bit at my wits' end (not that I know that much about bikes).
I used an old Gazelle Formula Randonneur frame and switched out most of the parts.
However, after some time of (rather light) driving, the wheel always comes lose and starts jamming.
Either the wheel isn't centered anymore and rubs on the frame where you can see "FORMULA RANDONNEUR" written.

Or it rubs b/w the cassette and the frame:

The only way I can prevent the wheels hinge from being too loose, is to tightening it down so hard that the wheel won't move :)
I went to a bike shop near but they only told me to simply readjust the wheel.
While I am able to do that, I don't want to do it on a weekly basis or in the middle of the night.
As far as they were concerned "this wasn't broken" -- but this can't be the solution to the problem, I hope.
I also found
Rear wheel won't move or keeps falling off
but I don't know how well this translates from a disk brake bike to mine.
Do you have any suggestions?
Some more pictures

It's some combination of:

QR springs not pointing the right direction. Try removing them completely while working on this, which can also help with the next thing.
Relatively thin steel dropouts not playing nice with this combination of QR skewer and axle ends. If the axle ends are poking through the dropouts and touching the QR nut or cam, or doing so as the whole thing presses together, it won't clamp right. This can happen sometimes putting new hubs and QRs on old steel frames. Solve by using a more traditional kind of QR, i.e. a steel internal cam one, and measuring to corrobrate you are well away from this being able to happen. Taking away the springs completely can sometimes be the quick fix to this problem.
Cam surfaces on the QR need lubrication. Put a drop of oil on the barrel that the lever pivots around.
The QR has some worn parts not seen in the photo, like the plastic bushing part.
You're undertightening the QR. Lubrication can help with this, or not, since external cam QRs are basically bad.
If your dropout alignment is wrong, for example by way of putting a 130 or 135 wheel in a narrower rear end, the QR is now needing to flex the dropouts back into being parallel before clamping happens. This can cause or add to the problem.
You've got horizontal dropouts and the external cam QR isn't providing enough holding force.


Any tips on riding a roll-off, followed by a trench? Any tips on riding this section of the trail? The land is sandy and the clearance afterwords is several meters.

I can't ride it slowly, as it is too steep and the sand will slide off. I suspect the suspension could probably handle the trench, but didn't try, let alone for jumping.

What is the correct way to pass this obstacle on a long-travel full-suspension bike? What about a rigid XC bike?

When I come across something like that, instead of riding straight down the hill I will head down across the hill on a diagonal. You can carry more speed this way and you won't hit the far wall of the trench and risk being sent over the bars, when your bike comes to an immediate stop.

This goes for any type of bike, rigid or full suspension.

If the risk of crashing in the ditch is low, I'll go straight down the hill while managing my speed. When at the bottom, simply lift the front end enough to clear the far side of the trench. This of course requires quite a bit of effort and/or skill depending on the surface of the ground, the slope you are descending the size of the trench.

Alternatively, get enough speed and jump the entire thing.


mountain bike freewheel hub stopped rotating So I was trying to replace my rear bearings and got stuck, (see question below):

how to reassemble mountain bike rear wheel hub and bearings

After this I felt confident to go ahead.  Was putting it back together with my son and we had it most of it back together (no cassette on it yet).  We put the quick release through the axle and span it, all seemed nice.  I held the freewheel hub bit and he span the wheel (slowly) and it made the normal clicking noise as it rotated.

So we tighted the bits and went to put the cassette back on.  After tightening the cassette locking nut we noticed that it was not rotating.  Tried loosing the cone hubs, nothing, tried taking everything off but still nothing.

I am not sure if I have somehow killed the wheel or there is something I need to do to get it rotating again.

Any and all advice on how to get this working / rotating correctly again would be greatfully received.

Thanks

Personally I think you have somehow managed to tighten the outer bearing cup that is part of the freehub body. It has two notches on either side, take the cassette off and see if you can knock the notches back to let the freehub spin.

If you have a Shimano hub you might want to also consider putting a new freehub body on there. These are LBS stocked parts albeit not an everyday request.

The bearings in the freehub can survive a bit of abuse, so long as you don't get too much dirt in there so consider DiY and, if that fails, pop a new freehub body on.


Shimano R785 140mm options I'm looking at replacing my wheels on my Cannondale Synapse, and I can get a pretty good deal on a set of Renolyds 6 bolt hub wheels, but Shimano does not make a 6 bolt 140mm set of rotors.

What I'm curious about is the suitability of some of the other manufacturer rotors (Avid, others ? ) and their compatibility with the 785's. I have some trepidation about using something other than Shimano rotors considering the importance of me being able to stop.

Is this something I should worry about?

Should I get the centerlock hubs so I can use their centerlock rotors (+600 bucks)?

Thanks.

If you can afford it, centerlock hubs are a nice option.  The rotors are easier on/off and have less tendency to go out of true owing to the large stiff carrier (Shimano).

If you don't want to pay for that convenience, I have used many other brands of rotors in the past, and apart for bends and break in periods not had any problems mixing manufacturers.  I've used Avid rotors with Hayes brakes and vice versa and just about every type with Formulas and not had problems.  After bending rotors beyond repair I've often had to buy cheap "in stock" rotors to replace them with and most often been pleasantly surprised when it all works out fine (until the next crash or incident).

In my opinion, the Centerlocks are well worth the upgrade money, but if that's not for you, just about any other brand of reputable rotor should be fine.  You can expect a normal short break in period as the pads wear to the new rotor.


What type of paint to use for a bike frame What's the best type of paint to use for painting bike frames, it's steel if that makes a difference?

I want to do a custom paint job and mix a few colours in a gradient effect. Should I use enamel paid, or an off the shelf car paint etc?

Also what paint should I use for an undercoat, a car primer paint ??

many thanks

Basically any paint that could be used on a car will work on a steel bike frame.

The better the paint the more robust it will be. Two-part epoxy based paints or powder coating are probably your best bets, but require specialized equipment. I think there are epoxy paints that do not require curing in an oven but you still need a spray gun.

You can probably use aerosol can paint with a self etching primer, meticulous preparation and good technique.


What are the best ways to start gravel biking for a complete novice (in the Bay Area)? I recently got a Cannondale Slate and because I’m a complete novice, I’m a little hesitant in starting to ride on trails alone. I’m mostly wondering if I’d have to perform many jumps (which I don’t know how to perform) on the trail. Any advice on trails or best practices would be highly appreciated.

Welcome to the Bay Area! First, you should become a member of Bike East Bay - they provide advocacy as well as produce bike trail maps for the east bay. Being a member gets you a discount at most east bay bike stores.

Second, the gravel trails around here are all fairly gentle in terms of terrain except for some steep hills. You could do them all with a hybrid if you're fit enough. So my advice would be to just find some trails - either along the coastline where it's flat - or in the hills where you get the view -- and just do it.

The best way to learn is to just ride! If things get sketchy just take it slow. There are group rides scheduled through Bike East Bay, REI, and other organizations. Check through them or places like Meetup.

PS: You can find some very difficult, double black diamond trails for mountain biking in the east bay but you'd really have to go out of your way to look for them. Marked trails on the bike trail maps (and on google maps) are all beginner level.


MTB Helmet on a Road-Touring Cube bike I'm getting the next month a Cube Nuroad black/red 2018 for my little trips and some commuting.

I got and old Btwin MTB helmet bought in Spain. Is it good to wear on this type of bike?

I'd use this bike for some gravel terrain, long trips and commuting.

Thanks!

The helmet itself will work fine.

On a road bike like the one you posted a photo of, your head and shoulders are usually a lot lower than on a mountain bike.  The visor on the helmet may block your forward vision because of that.  Or you may wind up having to force yourself to hold your head higher than is natural, which might be very tiring on your neck.  If so, just take the visor off.  It looks to have bolts/screws holding it on, so it's probably designed to be removed.

One comment:  that helmet doesn't appear to be very well ventilated.  If you do long rides when it's hot, that may be bothersome.  Then again, if you commute year-round, that may be very useful when it's cold.


Is there a road shoe cleat adapter (from road to mountain) that could be used in a cyclo cross race? So Im aware that you can buy (3 hole) spd pedal to (2 hole) mtb pedals so you can own one pair of shoes like this one offered by crank brothers. Has anyone ever seen a cleat adapter that could aid traction when running in a cyclo cross race (i.e. a pair of studs right at the front of the pedal)?

I have never seen a three to two hole adapter that also included toe studs.  Even if one existed you still have the problem of inadequate heel tread.  When you come into a barrier at full running speed and dismount, unless you have an aggressive heal tread (like on most mountain bike shoes), there is a good chance you will slip and crash.  Hitting barriers at speed sucks (I know this too well)!

If cost is an issue I suggest looking for used MTB shoes on a site like craigslist.  Used MTB shoes are actually the best as the sole has lost some stiffness letting you run better during dismounts.

Even if you came up with a method of adding a toe spike and heal tread to a road shoe, the typically ultra stiff road style shoe would be very difficult to run in.

Half of the fun of cross is running!  Well at least for me :-)


How to choose a compatible set of chain, cassette and chainring? I would like to change the chain, cassette, and the chainring of my bike. The cassette has 7 speed and chainring has 3. Is any combination of 7 speed cassette and 3 speed chainring built by any manufacture compatible? How should I choose the proper chain? Does any kind of chain from any manufacture work?

Bicycle chains are standardized. In general, cassettes, chains and chainrings are compatible with each other across manufacturers.

You just have to make sure you select a chain and chainrings that are compatible with the number of sprockets in the cassette. The number of rings on the crank does not matter.

(The difference is driven by the need for progressively closer spacing of the sprockets in the cassette as the number of sprockets increases. Chains for more speeds have to be narrower, which also affects chainring spacing and design.)

6, 7 and 8 speed systems all use the same chain width. Any manufacturers 6/7/8 speed chain will work for you. Similarly, any chainrings that fit your crank spider, and are designed for 6/7/8 speed systems will work.

SRAM and Shimano use the same free-hub body 'HyperGlide' standard (introduced by Shimano) so their cassettes are interchangeable. Other manufacturers such as SunRace use this standard too. Just check that cassettes are specified as Shimano / SRAM compatible.

A couple of notes.

A cassette is technically a stack of sprockets that fits on a free-hub style wheel hub, where the freewheel mechanism is built into the hub. There is a older standard known as a free-wheel where the freewheel mechanism and sprockets come as one piece. If you have an older or inexpensive bike you should check which you have.
If you replace the cassette you must replace the chain, as a worn chain will very quickly wear out cassette sprockets. Chainrings wear slowest. It's worth inspecting all three as one or two may not need replacing.
If you are thinking of larger chainrings or a cassette with a larger largest sprocket, you need to check if your rear derailleur can handle the increased difference between smallest and largest sprockets.


Triple to double crankset I have a new road bike that has a triple crankset. But I wanted to try double on it. When I replaced it. I found out that my standard square tapered double cranks won't fit with the bike's frame. Can I just instead use a double crank that is Hollowtech capable for me to able to do so? Because, correct me if I'm wrong, but it raises the crankset up a bit away from the frame right? Thanks I really appreciate any info.

The simple solution will probably be a longer bottom bracket. Square taper BB's come in a variety of lengths specifically for this reason.

Switching to hollowtech might work, but if your frame isn't built to that spec you could well have the same interference problems... only now you have new hollowtech BB and cranks.

This is one of those times it can be worth paying a bike shop. Not for the skill of the mechanic, but for the shelf of parts. They can try different sized BB's until they find one that fits, and all it costs you is labour and a single BB. Doing it at home you could end up with 3 or 4 BB's that are not quite right.


Sourcing Shimano Di2 6770 Parts Can anyone tell me where I can source a Shimano Di2 Ultegra 6770 rear derailleur since shimano no longer has replacements and left their customers high and dry?

If they don't sell/manufacturer them anymore, then your best bet might be the used market, such as Ebay.  This article has some interesting information.  It seems like it's possible to mix 6770 and 6870 parts if you haven't updated your firmware. Otherwise it says something about using 6870 derailleurs with 6770 levers. Which I think means you could upgrade your entire drivetrain to 11 speed, without changing the levers, which would make the upgrade a bit cheaper. You could probably keep your crankset the same as well, as I'm pretty sure that it would be compatible.

I don't have Di2 and I'm just going by what I've been able to find on the internet.  Do some more research. There's probably a good solution that doesn't require upgrading the entire groupset. I read a few other other articles while searching around, and it seems like Shimano did a pretty big disservice by dropping the 6770 product line.


Using 9 speed bar end shifters in friction mode with 10 speed derailleurs and cassette I am going to build a new bike, and I'd like to reuse my old bar end shifters if possible.

I prefer using them in friction mode.

Is it possible to use 9-speed Shimano bar end shifter on friction with:

Shimano 10 speed derailleurs/cassette?
Shimano 11 speed derailleurs/cassette?
Campagnolo 10 speed derailleurs/cassette?

Any problems to expect/consider?

Beyond the question of finickiness of actually using the system with higher cog counts, it's a matter of whether there's enough total cable pull from the shifter in friction mode to cover the range of movement needed given the cassette used and the actuation ratio of the derailer.

Here's an excellent article with the basic data you need to figure it out, snipped:

The only other piece you'd need to know is the actual total cable pull of your SL-BS77 9-speed bar end shifters, which requires measuring since 9*2.5 doesn't work because it's got some phantom movement both before and after its normal range of clicks when in indexed mode. I have them on a bike so I undid the low limit, put it in friction, put a mark on the cable and came up with 24.5mm total movement.

So, the answers:

Shimano 10 with a 10-speed Shimano road RD works because 24.5*1.7=41.65 (the total amount of derailer movement you get) and 3.95*10=39.5 (the minimum total range you need, here a smaller number than the 41.65). Shimano 10 with a 10-speed mountain RD doesn't work because 24.5*1.2=29.4.

Shimano 11 with an 11-speed Shimano road RD doesn't work because 24.5*1.4=34.3 (derailer range movement), which is less than 11*3.9=42.9 (range needed). Shimano 11-speed mountain RDs have an even lower actuation ratio (1.1) so we know that won't work either. So in other words, all the 11-speed shifters pull quite a bit more cable, so this friction shifter and probably many others out there in the world can't really sub in for them, primarily because the actuation ratio the systems run on has been made quite a bit different than in the past, plus the cassette itself is a little wider. You could almost do it by just using an older derailer with the 1.7 ratio, but not quite (24.5*1.7=41.65, and we need 42.9). Hacking the cable anchor to tweak the ratio by that much is probably achievable.

Campy 10 with a 10-speed Campy RD won't work, because 24.5*1.4=36.75, and 4.15*10=41.5. But it will work, barely, with a Shimano RD with the 1.7 ratio.


Efficient bike parking/storage that younger kids can handle? We have a smallish 2-car garage on our house, which with both cars in it, is difficult to put all 6 of our family's bikes in as well.  My bike is typically hung from some hooks in the ceiling, and I have a hoist on the ceiling for my wife's bike.  However, I have not found an effective way to get all the kids' bikes in.  I have tried hooks such as these:

which lets them fit, but I find that the bikes fall out of them quite easily unless the bike is lifted all the way off the ground, which the kids lack the ability to do.  I thought of putting in more hoists, except that there is not enough ceiling room left to do so (without coming down on a car, that is) and I'm concerned with the kids securing them wrong and having one fall (damaging the bike, the kid or a car).

Does anyone have an innovative way to store multiple bikes in a tight space that does not require significant lifting?  The kids are able to get the bikes up on a rear wheel, but not typically to lift it enough to get it in a hook that would keep it off the ground.

Depending on your garage arragement, I would consider sth like this, but for vertical position:

mixed with hoist:

with this kind of elevating mechanism:

If for horizontal, can be combined with this ( I suppose there is enoug space on the wall if you tried with hooks):


Can I patch a tire (not a tube) that has a hole? I've got a relatively new bike tire (hard case Bontrager) that got punctured by a nail. So now the tube bulges out of the tire and is of great risk of bursting (though I biked several miles before realizing this).

I'm wondering if it is possible to patch the tire?  If so, how would you do this?

I'm guessing you'd want a non-stretchable patch.

To get you home, you can use a tyre boot. This is essentially a non stretchy patch that sticks on the inside of the tyre. They're not recommended for long term use but people do run them long term (for example relegating them to a commuting bike/wheelset). If you do use them long term it's a good idea to check then occasionally. This assumes tubed tyres.

Boots also don't work next to the bead as there isn't enough material for them to stick to and resist the considerable load.

I've improvised a boot from a glueless patch (and run the tyre soft). Crisp (chips) packets, gel wrappers and strong banknotes are also used. Something sticky to hold it in place while you reassemble and inflate is a good idea.


How to get this dustcap off? I have this problem where my pedals seem to be able to be able to rotate on an axis perpendicular to the straight travel of the bike.  To take off the cranks, I need to get past a dustcap.  Unfortunately, the dust-cap looks like this:

That hole in the middle is supposed to be slot for a screwdriver, and I can't get it off.  Whenever I put enough force piece to move it (it's been cross-threaded) the metal deforms - it even feels soft.

Could someone please tell me how to get this thing off?

At the stage you're at I normally vandalise them out. Get a big flat head screwdriver and use it more like a chisel - wedge the flat under the parts I can see and break them off, trying to break the part that has the thread on it at the same time. Plastic caps usually shatter while I'm doing that and all the bits fall out.

If not I remove the bottom bracket bolt or nut now it's exposed so I have better access, then I get a knife and shave away the plastic until that remaining threaded ring falls apart. With aluminium that will be harder but is usually still doable.

One alternative that I usually try early on is to cut a groove across the ring (parallel to the BB axis) and try using the screwdriver to turn the ring using that.

So far that hasn't failed for me, so I have no idea what to do next. I'd probably use a dremel or a drill to try cutting that ring.

(I've done this quite a lot, I've been a bike mechanic. But 90% of the "stuck" ones shatter when levered open as described, leaving you picking out loose pieces.)


SRAM XD driver body wear I was climbing a steep hill, and all of a sudden my pedals started spinning freely. The freewheel had given up.
I removed the cassette and found the XD driver looking like this:

The areas around the pawls are damaged, and the bearing is cracked. My guess is that the pawl somehow managed to flip and put a ton of pressure onto the bearing below.
Wheels are Reynolds TR249, relatively new (2k km), serviced only once (two bearings changed, one in the cassette body, one in the wheel hub).

Questions:

How does a cassette body get worn that fast, in such a fashion?
How can a cassette body bearing CRACK??

Many hubs with similar designs have such a spacer in the "between 2 and 7" position as per the diagram. Were the hub intact you could test whether it's supposed to be there or elsewhere, because if it was supposed to be between the drive side main hub bearing and the inboard freehub body bearing and it wasn't installed there, typically the freehub body would bind up and the seal wouldn't engage right. And if the spacer was there when it shouldn't be, the pawls wouldn't fully engage the drive ring (4), which would be easily noticeable during assembly and would also be evident as a 2mm unworn section on them, which it isn't in the images. I highly doubt the spacer was in the wrong place, and that piece of the puzzle can be resolved by calling or emailing the manufacturer.
To me it's hard to tell what went wrong first in this scenario. The evenly spaced scoring on the freehub body around the flange that holds the pawls presumably came from it being rammed against the teeth of the drive ring under load. That would seem to suggest play or flex in the freehub body, which could have happened after the bearing failed, or perhaps something else caused both it and the bearing failure.
It appears this design uses slip-fit endcaps and a main hub axle with no threads anywhere. In such a design, the thru-axle is what's holding all of the hub parts together. If the thru-axle were ridden loose, I could imagine failure like this resulting.
From your picture there's at least one tubular spacer inside the freehub body joining the two bearings. That and the two bearings being the only things inside there would be typical, but sometimes freehub body internals have other parts inside like snaprings to locate the bearings. If any of those parts were out of place when the new bearing was pressed in, the bearing might have wound up where it should't, causing the scoring you see on the end of the freehub body as well as potentially other problems. But that likely would have all been evident as excess friction in the freehub body when you started riding it again after the bearing change.
I think a huge clue in all of this is that you needed a new freehub body bearing so early in the life of the wheel. That is weird. Freehub body bearings have easy lives because they only receive load when they're not rotating. It's more often the case for them to still be going perfectly strong when everything else on the wheel is finished. I'm curious if there's some kind of tolerance problem in the bearing bore(s) of the freehub body, or perhaps the axle. That could explain both premature wear of the first bearing and failure of this one.


Safety Bike Tail Light with Directional Signals I am a urban rider that I ride locally on a regular basis but I am always concerned about fighting with cars on the streets.

When I traveled aboard last year I ran into a manufacturer who has a tail lamp that has some unique safety features including:  1) Light-sensing hazard light that comes on when it detects dark surroundings (like going through a tunnel) ; 2) motion-sening break light that comes on when it detects deceleration ; 3) left/right/hazard signal lights that can be controlled by radio frequency using a control panel mounted to the handle bar.

This tail lamp I thought was perfect to tackle safety concerns of riding in the city streets.
I currently have one that I installed on my bike and I am thinking of importing this product into the country to try to offer other cyclist who may have the same safety concern I had.
However, this tail lamp is rather costly compared to what you can find on amazon or ebay these days.
Its MSRP is about $90 - $100 per.

So I am posting to seek opinion/advise if anyone think this tail lamp would be worth the investment before I decide to take the plunge to import bulk quantities.
Any advise is greatly appreciated.  Thank you.

All this is very much depends on how good you are as a salesman. Very good salesman can sell sand in a desert and make good living.

I'm not sure what market you are talking about, but in UK you can get very different price range for the lights, top models priced at £144 ($227). And I have seen these lights used on the streets.

So $90 makes it costly for most of the people, but certainly you would find your customers who would want the set of features you are talking about.


26 x 1.75 front wheel will work on a bike with a 26 x 1.95 rear wheel size? I got a 26 x 1.75 front wheel. Tire and tube 26 x 1.75. Upon further inspection, (I got confused) The existing rear wheel and tire is 26 x 1.95. Will the front wheel size be  okay to use?

Provided the wheel fits into the bike and you can use the brakes, it'll be fine to use.

People run different tire sizes on occasion, and in some cases even different wheel sizes (e.g. 69ers and 96ers which have a 26" and 29" wheel).

In some applications, its even desirable to put a bigger tire in the back since it carries more weight than the front. This can give some more comfort, e.g. for touring.


Old chain still shifting perfectly, should I change it out? My chain is ready to be replaced according to gauge, but, my shifting is flawless. Should I replace the chain or squeeze another few hundred miles out ? It currently has about 2500 and is a CN6701. Thanks !

You didn't mention what gauge you used, but there are many kinds. Take a look at that link; it is worth reading, as is this thread.

The current smoothness of the shifting isn't usually the deciding factor regarding when to change, but rather the cost of the other components that wear faster when the chain is worn: the cassette, and the front chainwheels. The idea is to replace the chain (relatively cheap in comparison) before it starts to damage the more expensive cassette and front chainwheels.

In my experience I get about 2,000-2,500 miles out of a CN-6701, and I'm riding in near-ideal conditions (Southern California weather). I'm pretty careful about keeping my chain clean and properly lubed. I typically replace the cassette about every three chains, and the front chainwheels (Ultegra as well) are still OK.


Trek 520 model changes during years What are main changes in Trek 520 during the years? I have possibility to buy new Trek 520 year 2015 for 1000 Eur and year 2018 for 1300 Eur. Is there right place to safe some money?

What are difference between 2017 and 2018 models?

The primary difference between the 2015 and the 2018 seems to be the availability of disc brakes. The decision will depend on how much you think the disc brakes will improve your ride quality. I would take both for a test ride and see if you can really feel the difference in braking quality. The discs may give you better braking in wet or muddy conditions especially if the bike is loaded for touring. A concern may be the availability of disc brake parts if you travel in very remote areas.


Refurbishing everyday bikes I'm looking to get 3 family bikes functioning as well as possible. I've replaced all the cables, but now want to get the gears as close to new as is sensible.
All bikes old >10 years I would guess:Trek 4300, Kona Lana'i & Ridgeback mx24.
Initial Q is, apart from the chain & cassette, which gear  components degrade the most? Rear mech, front mech, shifters & chainring.
Trying to do a cost-benefit analysis.
Ta

Depends how they've been stored.  If they were inside a garage or otherwise dry, then that's a lot less work.  If they were outside or damp, everything will be that much closer to EOL.

Gear changes and brakes: if there's been moisture in the cables then they can suffer but housings and inner wires can be replaced.

Tyres and tubes can degrade in heat.  Oils and greases will thicken and congeal so an all-round service of bearings can be in order.

Finally, why were they unused for a long time?  Was there a fault that was too hard to fix at the time?   Look for function.

On the other side, sometimes a good wash, and a lick of paint can make an old bike appear very much nicer too.


Can I replace the 32 mm tires on a Trek 7.3 with 35 mm tires? When I bought a Trek FX 7.3 instead of the 7.2, the bike dealer told me that the tires were the same. They looked narrower, but I thought it was just that I was used to my other bike. I found out later that the FX 7.3 indeed has narrower 32 mm tires.  Can I put 35 mm tires on my FX 7.3?

32mm to 35mm is a small change. It's not going to make a huge difference in ride quality and because it's a small change, any bike that comes with 32mm tires is very likely to handle 35mm tires with no difficulties.

The 7.2FX and 7.3FX are the same frame, but a different fork. It's hard to be sure from the online description, but probably also the same brakes. The wheels are different, but it's a small enough tire size change that it's not a problem. All the geometric specs are identical for all sizes between the two models.

If the 7.2 works with a 35mm tire, the 7.3 will almost definitely work with the same 35mm tire on the rear, and very likely work with the same 35mm tire on the front.

A 35mm wide tire should be 1.5mm wider on each side than a 32mm tire, and will have a similar increased outer radius. 1.5mm is the thickness of a US penny (or a smidge more than the thickness of a dime), so you can use a couple dimes to measure.

Is there at least 2mm of room on each side (and top) of the tire where it passes through the top of the fork? Same amount of room or more where it passes through the brakes? That's the most likely problem areas here.

Double-check the back if you're still worried: is there 2mm clearance around all sides of the tire where it goes through the brake, where it goes between the seatstays, where it goes through the chain stays and where it gets closest to the seat tube?

If all those check out, then you're in the clear.  If it's a close call, you'll just have to try it, or go into the shop and ask them to help you see if it'll work.


Can Press-Fit Bottom Brackets be used in a Threaded frame I recently tried to replace an sealed cartridge bottom bracket with a threaded hollowtech system.  In the process I shredded one of the threads and can't get the hollowtech cup in.  After some study I noticed pressfit bottom brackets are compatible with hollowtech.  Is it possible to install a pressfit BB into a threaded frame?

You can't put a pressfit bottom bracket in a frame not designed for pressfit bottom brackets.

Your best options are:

Taking the bike to a bike shop and seeing if the threads can be salvaged
Use an universal threadless bottom bracket like the Velo Orange Grand Cru threadless bottom bracket. And buy a square taper-compatible crankset.
Follow this question's advice.


Pins and needles in my fingers after long rides I've started to get pins and needles in my little finger and the finger next to it some times after riding for over an hour. The roads are quite rough and vibrate my handle bars quite a lot. I also wake up some mornings with tingley fingers. I think that might be related to cycling, but it could also be that my fingers spend a lot of time typing.

Is this something that I should be worried about and is there anything I can do to prevent it happening?

Talk to a doctor

The symptoms of waking up with tingly fingers make this sound consistent with carpal tunnel syndrome to my non-doctor opinion.

Basically, as I understand it, a little bit of that now and then isn't a problem, but too much over time causes damage which can be permanent and cause some major hand problems.

There's a bundle of nerves and tendons that run through a narrow channel in your wrist. Pressure on that area, or using the tendons with the wrist in a non-neutral position can, over time cause problems. That can mean biking and typing are causing you trouble. Pressure on these nerves will tend to cause numbness and tingling in the thumb, index, middle and part of your ring finger. Vibration of the hands (such as from rough ground) could be the main problem instead of pressure.

There's also the ulnar nerve on the "pinky" side of your hand that can have the same kind of problems.  Pressure on this nerve (or stretching/hyperextension) will tend to cause numbness and tingling in the pinky finger and part of your ring finger.

Diagnosing exactly which problem you have is best done by a doctor, not the internet.

Assuming you talk to your doctor and they suggest avoiding the hand pressure your bike is causing, some things to help avoid these problems on your bike include:

Get a professional bike fitting
Don't hold the bars tightly, hold them loosely
Gloves with padding matching the pads of your palm (no pad on central channel, that will make things worse).  Sadly many gloves aren't really designed to help, so you have to know what to look for.
Some bar grips are designed to help
Changing how you ride to put less pressure on your hand (use core muscles to hold body up)
Raise handlebars and/or move them closer to you so that you have less pressure on your hands
Handlebar ends to give more hand positions
Different style handlebars (new bike with drop bars?) for more hand positions, preferably with main position not putting pressure in center of palm
Vary your hand positions more often.  If you have bars that allow multiple hand positions, use them.
Take breaks during your ride.  Even just taking your hands off the bars for a minute at a stop light could help.
There may be stretches you can do during such breaks to help
Pedal harder/faster. If you pedal hard enough, you'll find yourself pulling your body down with the handlebars instead of pressing down on your hands.
Run your tires at a lower pressure. Replace with fatter tires if necessary. This should help reduce road vibration.

Some references:

http://www.hughston.com/hha/a_15_3_2.htm
http://www.webmd.com/pain-management/carpal-tunnel/carpal-tunnel-syndrome-topic-overview
http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001469/
http://www.mackinacislandnews.com/news/2007-06-30/news/014.html


Need magnet for RPM and speed sensors I bought used speed and RPM sensor by echowell. Here is a picture with this product and I highlitghted in red components that are missing. So as I unserstood this is magnet for sensors. Question: can I buy regular magnet for sensor in bike store or does this system require specific magnet made by echowell?

To a large extent a magnet is a magnet (so long as it's strong enough).  You may have to mount it in the correct orientation.  A spoke-mounted magnet is quite easy to make or cheap to buy. The one that mounts on the crank for the cadence sensor may be a little harder, but I've got one that just relies on fixing to the pedal axle with its own magnetism (from a sensor that's too cheap to actually work reliably). You might not need a bike shop in that case.


Brand new BR-R7070 brakes, piston issue The ceramic pistons on my brand new BR7070 brakes won't depress at all even with quite a lot of force. There is also a subtle grinding noise when trying to depress the pistons. Did I somehow crack the brand new pistons? How much force does it take to depress these?

I disassembled the caliper and the ceramic pistons were both shattered. They were either shattered on arrival or this was from trying to put a bleed block in when the pistons were slightly out. This pushed the pistons into a slight angle. Then they shattered when squeezing the brakes.


My bike leans to the right. What should I check? The bike I use to commute - a cheap, no brand city bike - is unbalanced, and naturally leans to the right. This is not noticeable normally, but it's enough to make riding without the hands on the bars requires quite some effort to avoid drifting right.

Of course I can't just ask you what the cause is, but could you help me in finding it? What should I look for/test/check?

a) Is the headset tight? Over time that can loosen up and it'll start to lean in one direction or the other (usually based on which side of the pothole you just hit).

b) Are your wheels true? this probably won't make a major difference but it might combine with the previous point.

c) Is the weight on the bicycle evenly distributed? E.g., do you wear a messenger bag across your left shoulder so the weight of the load pulls the bike in that direction?

d) Does this happen in a parking lot as well as on the road? Don't forget that streets aren't flat - they curve off to the edges to allow water to shed from the roadway (and into nice deep puddles for motorists to drive through and splash cyclists). If it only happens on the road (and you always ride on the right hand side of the road) it's probably because of Gra-vi-ty.


Lateral movement on rear cassette My cassette (SRAM XG-1175) moves axially about 5 to 8mm (in line with the axle, not up and down) on my hub (whatever is standard on a 2016 Enduro Elite)

But the part of the hub the cassette mounts to also moves with the cassette.

What could be the issue here?

The 'part of the hub the cassette mounts to' is the freehub body. That is evidently loose, or damaged.

5-8mm is a lot of movement. Don't ride the bike until you have fixed the problem. You would likely damage the freehub mechanism, and may suffer a jammed chain which could be dangerous.

Each manufacturers freehub disassembles in a different way. This Park Tool article will give you and idea of the types. First step is to get your cassette off and find out what type of hub you have, then find specific instructions for disassembling and inspecting it.


Planning to purchase a road bike I am 57 years old, 182 cm and weigh 105 kg. I have been cycling for the past 5 years, mostly with a city bike, Trek 7.5 FX. After a trial of a long distance lasting a week with that bike, I realized what it meant to be more aerodynamic. What would be the best option for me? More of an endurance type or more of a performance type of bike, such as Trek Madone 5.9? I tended to avoid bending forward while cycling too much until now. However, seems that I need to. 56 cm versus 58 cm? Any experience or thought would be very much appreciated. Many thanks in advance.

You basically get what you pay for, so there isn't any secret formula. Trek is one of the largest manufacturers on the planet, and is probably as good as any other on the market.

But have a look at, and test if possible, other bikes as well as Trek, because different models have different geometries, and another geometry might feel better to you.

Size also is only really judged by testing, but 56 or 58cm seems a good place to start from what we know about your height. In truth there is very little between these two sizes, so it is unlikely it would be a straight "fit"/"not fit" scenario. More likely one size will feel a bit more comfortable to you than the other. If two frames do feel absolutely the same, the smaller frame will tend to be a small amount stiffer and lighter.

Often with bikes you'll face a trade-off between a better frame or better components. Of course, it depends how averse you are to upgrading the bike after the initial purchase, but be aware that many components can be upgraded later (although it isn't very cost-effective) but upgrading a frame is usually prohibitive - more likely than not you're then in the realms of buying a new bike.


Help identify this mixte A mixte frame with bcn stamped on front, 224 stamped on bottom of frame, Mafac racer brake calipers, Simplex shifters, Suntour derailleuers and hubs, Weinmann brake levers.

Just a guess, but it looks a lot like a motobecane to me.


Sora STI Shifters with Deore I'm building a touring bike and was interesting in using STI shifters, just wondering if this setup will work.

Shimano Sora 3500 STI Triple 3x9 Speed Road Lever Set
with
Shimano Deore M590 Top Swing 9sp Front Mech
Shimano Deore M592 Shadow 9 Speed Rear Mech

Thank you :)

There are many answers here that cover variations of this question in more depth, but the answer is not really, because Shimano front derailer cable pull is different between mountain and road. What tends to happen as a result of the combination you describe is it does shift, but performance is lacking and there will invariably be FD cage rub in some gear combinations  that you'll never be able to adjust out. You read conflicting things about this because it does in fact shift and kinda sorta work from a certain perspective and that's good enough for some people. The rear is matched perfectly because all 9 speed Shimano shifters are the same cable pull, mountain or road.

Solutions include bar-ends with their friction front shifting (which is good for other reasons on touring bikes because it's less finicky and tends to work better in situations where you've chosen whatever chainring sizes you want as opposed to what's prescribed), a shift adapter such as Jtek, or pushing the limits of what road front triples can do (this also compromises performance). Another very good approach is using 10-speed pre-Escape Ergo levers with the so-called Hubbub mod aka Shimergo, which is a hack that makes them work with Shimano 9-speed rear derailers and cassettes while the front has lots of small clicks and can basically shift anything. In practical terms most people just use bar-ends here and leave it at that though.


SRAM GXP crank installation and rear hub preload I just had some new BB bearings installed and am going to put the crank in but have two spacers/dust shields I am uncertain of position. I had everything laid out how it was removed but it got mixed up :(
Bike is a Trek Superfly 6 with a Sram GX crank. I have a note that the BB is "PF89.5 SRAM GXP" (Also how does one find a kit online for this? I relied on the LBS to figure that out but I do like to learn where/how etc...)
Posted photos of the parts here:

Have not really been able to confirm where the two black spacers go? One on the left is kind of a seal. Other is what looks like an aluminum spacer. The new seals over the bearings are shown held on by a zip tie as they came back from the bike shop. I just want to ensure I get the order correct. And wonder if the black seal on the left of the first photo is no longer needed with the new bb bearings? I suspect the black spacer(on the right) goes on the drive side between the "Spring washer" and the crank. And the left seal I don't know, but suspect non drive side.

Also, for the rear wheel I replaced a bearing as well. Its a sealed bearing and just want to confirm how tight I put the "cone" nut in before locking the lock nut up against it. Does it get set finger tight to snug so there is no play in it by moving it with your hand? Then lock it with the lock nut?

I'm more used to working on cars than bikes and am trying to be careful as they seem like they would be easier to break things.

By amazing co-incidence there happens to be a video on YouTube showing SRAM GXP crank removal and installation on a Bike Trek Superfly 6.

            .

Referring to that video, on the non-drive side it's (from inboard to outboard): red rubber seal, black plastic spacer, metal wavy washer. On the drive side there is only the red rubber seal.

Looks like your bike shop has omitted the black spacer on the drive side.


Is an SLX M7000 crankset compatible with the rest of my drivetrain? I ride a Comencal Meta HT AM Origin. Unfortunately I need to buy a new crankset. I’ve been thinking about Shimano SLX FC-M7000 34-24T with a new bottom bracket, BB-MT800.

Do you know if that crankset will work fine with the SRAM x5 parts which are currently on my bike?

I'm not sure if there would be any problems mixing SRAM and Shimano per se. The SLX crank is a higher end component than the X5, so you would be buying more than you need, and you get problems mixing 9 and 11 speed components.

The 11 speed SLX crank uses a narrower chain than 9 speed. The 11 speed chainrings are slightly closer together which may give you shifting problems and chain rub as your front derailleur is designed for 9 speed chainring spacing.
By choosing a 24/32 crankset instead of 22/36 you'll be loosing high and low ratios. The smaller chainring gap on the SLX is made up for by a wider spread of sprocket sizes available in 11 speed cassettes.

Upgrading one component several steps - even something major like the crankset - does not make a significant difference to the bike overall, and here you'd be introducing other problems. Better to play it safe and get a SRAM crank. I think all SRAM X-5 through X-9 cranks are now nominally 10 speed but each line includes 9 speed rear derailleurs so they should work fine for you.


Bottom bracket servicing My crankset is driving me nuts, because of creaking noises when pedaling.

I have fixed the issue twice already, by removing the bottom bracket (FWIW, it's a 68x115mm square, pictured below, and my frame is aluminium), cleaning everything up and installing it back, with some fresh lithium grease. However, the creaks come back soon, like after a week or two (about 30km ride per day), or after some heavy rain.

I had been tightening the strongest I could, but using a simple 24mm wrench, with the bracket tool ripping off again and again... Note that every time, the subsequent disassembly was very easy. I guess I wasn't tightening strong enough. As I have to fix it again (*cries softly*), I just bought a 300mm torque wrench, and will tighten to 40~50 Nm.

Long story short, am I right assuming I wasn't tightening strong enough?

Update: So, I've just spent 3 hours cleaning (this time very, very thoroughly) and reassembling everything. About the torque, 50 Nm is not as strong as I thought, and I think I fastened strong enough the previous times. When I rode the bike afterwards, there were the exact same creaks are before (*cries softly*). But after like 1~2km, they disappared, and no noise for the rest of the ride (about 10km, under heavy rain). In fact, that's also what happened the previous times…

But after I have reinstalled the crankset, I turned the pedals by hand very fast, with the chain removed. Looking at the screw head of the left arm, I noticed it was very, very slightly waving. Which indicates the axle is slightly misaligned or  bent.

Thus, I begin to suspect the culprit for the creaks is the bottom bracket itself. Do you think my assumption is right?

Update 2: So, today, the annoying creaks are back, exactly as before (*crying intensifies*). Maybe it's the BB itself, but I'm also suspecting the chainwheel aluminium bolts (even if I've greased them), and the pedals (magnesium platforms, which seem to easily propagate noise). I'll have to proceed by elimination… Also, note that after a sudden rain (again…), the bike got very wet and apparently it makes the creaks to disappear.

Update 3: After some trial and error, found it! It was the pedals, as simple as that… Some AliExpress titanium pedals, great at first glance, but that degraded fast, and with many design errors (here for instance, I cannot disassemble them because there is not enough room for the head of the socket wrench). Thankfully, AliExpress already had reimbursed me because of conception errors of this product. It's a shame because they were lightweight and there isn't much alternative, but the creaking noises are a huge no-no for me. Basically I just eradicated 95% creaking noises of the bike :)

Locktite blue (also known as 243), or other similar thread lock liquids may eliminate the bottom bracket threads coming loose.

Another method to stop creaks between the BB and the frame is to use plumbers teflon tape. Just one or two wraps on the BB threads before installation will keep the bottom bracket from backing out and fill voids to eliminate movement and creaking.

Many times simply cleaning and greasing the BB and frame threads will also fix the problem.

If the problem disappears for a while after disassembling and reassembling, the bottom bracket and cranks then the BB/shell interface likely is the source of the problem...

-BUT-

Creaks can come from many sources yet they will sound like they are coming from the bottom bracket.  Some other common sources to check:

Cassette: Tighten down the lockring. I've had this happen to me a couple times.

Seat rails were sliding where they went inside the saddle.  The creaking disappeared when I stood.

Handlebars creaking inside the stem. Fix by lubing the bars and reinstalling.

Stem to steer creaking. Disassemble, clean, grease, reassemble.

Chainrings on crankset: Loosen and retighten the chainring bolts.

My recommendation is to fix one item, see if the creak persists and if so move on to the next.


What maintenance to do after buying a brand new road bike? I've just bought a new GMC Denali road bike.  I've put it together, but riding it has revealed that there are a few things that need to be fixed, such as the front-side brakes being too loose.

Is there a common list of maintenance and adjustments to be made to the bike before I should start riding it regularly?  Or should I just ride it and fix the adjustments as I find them?

Before each ride I do a quick safety check:

Brakes adjusted correctly
Handlebars correct, wheel in line, headset tight
Saddle/seatpost tight
Pedals and crank look good
Chain looks good
Wheels true (maybe not perfect, but quick spin shouldn't show huge
wobble or brake rub)
Quick Release Tight/Hub Nuts Tight [thanks Kibbee]
Tires inflated

With the exception of the "tires inflated" this takes me about 30 seconds. The "Wheels true" I do by just spinning the wheel and looking at distance to brake pad. After first revolution I can stop wheel where I need to align stem for easy pump.

"Tires inflated" I do by hooking up the pump and topping them off. If I had a flat on the last ride, I let out the CO2 and replace with air, otherwise I just take them back up to whatever pressure I use for the particular bike and conditions.

This list is also the list of things to NOT wait to find out before fixing.

On a new bike, you will also want to adjust for cable stretch on the derailleurs during the initial period. Many bikes have barrel adjusters that make this simple, but looking at the close up pics of the GMC Denali, it looks like this bike does not. Simply put, the lower priced bikes are able to be lower priced in large part by making assembly cheaper and using parts that are cheaper to make. This is NOT to say that it's not a very serviceable bike. Most of the tradeoffs just make it a little bit harder to maintain. The two that affect adjusting cable tension are the lack of barrel adjuster and the use of a regular nut rather than a hex bolt to hold the cable.

You can make the same adjustment, you just have to use a different tool. First, don't worry about this until your shifting starts to get a little bit sketchy. Once/If it does, you will want to shift to the smallest cog ( rear gear) for the rear derailleur. Then loosen the nut holding the rear derailleur cable and just pull it "strong finger tight" and retighten the nut. If this doesn't help there are easy ways to work through it, but come back and post another question so we can make sure we talk you through it.

The front derailleur generally isn't quite as affected by stretch, but if it becomes harder to get into the bigger chain ring (front gear), do the same thing...shift to smallest chainring and loosen nut, tighten cable, tighten nut.

Happy Riding!


How dangerous are my worn rims? I took my bike for a service recently and was told it needed so many repairs that it was more cost effective for me to replace it.

One of the repair jobs was to replace the wheels due to worn rims. The shop told me they were so dangerous that they refused to replace the brake blocks - which were also dangerous - for fear of causing extra wear.

I am happy to replace the bike but this is a bad time to do so. I'm looking to move house and my eventual location may impact what kind of bike I buy. I'd like to ride on my worn rims until then.

The rims have a groove to indicate wear. The groove is still visible but it has become very shallow:

I've sorted the brakes for now by tightening the cable. But realistically how safe am I riding on these rims and for how long?

Rims are worn out when the groove disappears. If the groove is clearly visible, well-defined and of uniform depth all the way around, the rim is not quite worn out and certainly not dangerous.

New brake blocks will cause less wear as they will be free of hard particles of grit and metal that get embedded in the relatively soft rubber over time.

Given the repair shop's bad advice on the state of the rims and refusal to replace the blocks, I'd disregard all of their other advice about needed repairs. I suspect they just saw a well-used bike and decided they could persuade you to purchase a new one. Find a repair shop with a better reputation and get a second opinion.

Replacing and adjusting brake blocks yourself is relatively easy if you have basic tools. Park Tool has an excellent web page and collection of videos that walk you through the process.


Is my bike getting ruined? I have a 2015 Giant Trance that is about 3 weeks old. Used pretty much every weekend. It's kept in a shed (fully covered,  no insulation just a regular shed), after every ride I give it a nice clean with a hose lightly over top, use an air compressor then use a micro fiber cloth to dry down and tidy up. My bolts, chain and discs for my brakes seem to have a lot of rust on them for 3 weeks old.

I have 2 questions:

Is this rust bad for my bike and if so, how do I remove it?
Is cleaning it with a hose, using the air compressor then the cloth bad for the bike and maybe making it rust?

Sorry if this is hard to understand, feel free to ask questions to know more.
Thanks!

P.S. Where I am from there is a lot of sulphur in the air (it's bad enough people visiting smell it very easily) so maybe that could be apart of it? It's also summer (southern hemisphere) and our trails are mainly in the trees, with the occasional tracks where trees have been cut down. Hope this helps.

Chain will rust always after washing (or even light rain or a puddle of water), if not re-lubed. I think this is detrimental to the chain, as it removes material from the rollers and thus contributes to chain stretch.

Bolts for stem, handlebars etc. seem to always like to rust after rain or washing. I don't think it is a big deal, but it ruins the look of the bike. How I solve this is put a small amount of grease at the bottom of the bolt head (and then wipe any excess). The grease seals the hollow head and stops rust. Using a hex on the bolt removes most of the grease, so re-lubing after repairs is nice.

About the disc brake rotors - this surprises me. Apart from two general advices, I can't see how can I help with this. Firstly, after washing a bike, lift it up several times and force it into the ground - this should should shake a lot of water off. Secondly, after that, you can make a couple of hard stops - the disk pads will dry the disks in no time.


Ambidextrous backup downtube shifter for touring? I'm heading out on a long tour soon on a bike with Shimano STI shifters. That choice was intentional as I don't like bar-ends. However, I notice the gear cables run through stops at downtube shifters bosses and I'm curious if there's a type of cheap friction shifter that would mount on those and could be used on either side that I could carry as an emergency replacement in case an STI ever crapped out.

Here is a picture of the bosses on this bike:

If someone could point to one or more specific models that would fit this, that would be great. Again, the emphasis is on cheap. If I break an STI, I would only need this to limp a day or two to the next major city (tour is in Canada). So I don't want to drop $100+ on some bespoke hand-milled stainless steel shifter.

We need to see what is under the cable stops. My guess is that is is probably a standard squared off shifter boss, but you never know. If it looks like this

Then any friction downtube shifter should work as a backup. You want to get
one that is not indexed if at all possible since that way you can use it for
either front or back derailleurs. Bar end shifters use the same mount, so if you have some of those handy you can see if they fit. The cheapest solution is probably to buy a cheap pair of Sunrace Clamp-on stem friction shifters.

While the levers are different, they can be interchanged. You should probably test this in case there are clearance problems and you need to trim the lever
a bit.

As to whether this is worth the cost and weight, I'd say it depends on the remoteness of the tour. If you're within a day's ride of a bike shop for the
entire tour, then it's probably not worth it. A credit card makes a handy backup
for a lot of parts.


Bicycle design for a crooked hip One of my hips turns out a bit more than it ‘ought’ to.  It doesn't affect my walking, but on a bicycle it means that my knee on that side must transmit force at an unnatural angle.  It was less of a concern when I was younger and lighter, but even so it's probably why I had considerable intermittent knee pain in my teens.  Now I don't ride at all.

Do bicycles exist that I could ride without pain?

Similar to the other answers it would be worthwhile getting a professional to assess your current bike fit (and potential modifications that may be required).  If possible I would suggest a sports physiotherapist that specializes in bike fitting. They exist, I have used one before.  A physio will be best qualified for assessing how changes in position can affect your hip and knee functioning.  While many bike fitters have some training (and often good intuition), dealing with severe dysfunctions may be out of their area of expertise.  Alternatively, you may need to facilitate a relationship between your physio and bike fitter if you cannot find a single person who can wear both hats.

To give you hope that it is possible to tweak a standard bicycle here are some things that could help (with the right guidance):

leather hammock saddles (e.g. Brooks) break into a custom form fit for each rider. During the break-in phase you are physically tearing the taut leather until the pressure is equalized across the saddle.  This results in custom form fitting that can accommodate different pelvic tilts and orientations.  Be warned however, the break-in period can be long (although water break-ins can speed this up considerably at the cost of leather longevity).
Shoe shims exist to help angle the foot differently to optimize knee alignment. Also foot orientation on the pedal can be used to help modify knee tracking.
Shoe shims can also be used to accommodate for structural leg length differences.
You may consider flat pedals over clip-less so that you can continually modify your positioning to reduce the likelihood of repetitive stress injuries.


How tight should your stem valve nut be? I just got new schrader valve tubes that have the rim fitting nut on them.

Since this question has not been asked on here before, what is the proper tension that the nut should meet the rim? My understanding is that the nut prevents the tube from slipping in the rim and being damaged over time.

My questions are:

Do you tighten the nut before inflation, or after inflation?
After inflation should the nut be finger snug or tightened with a wrench?

You don't need the nut, really (and its rather abnormal on Schrader valve tube) -- a lot of people just throw it away.

The point of the nut is so that the tube's stem doesn't go into the rim when you're trying to inflate the tube and the stem doesn't move around when you're trying to pump the tire. Note that the tube can only go significantly into the rim if the stem is very short relative to the rim or the tube has very low pressure -- you won't see its effects when topping up your tires.

If you're using a Presta valve in a Schrader valve rim, they sell specific grommets for a few cents to use to keep the Presta valve secure, though some people install the nut on the inside of the rim to act as the grommet.

If you want to use the nut, inflate and lightly tighten it down after inflation with your fingers (there are some other schools of thought on how to use them, but this is probably the simplest). Don't over tighten it or you'll damage the tube.


Dealing with very juddery cantilever brakes I'm a commuter with a ~13m daily round-trip. I've been riding this on an MTB for 8 years, but I'm looking to upgrade. I recently tried out a 2012 model Specialized Tricross; this having been recommended as a road bike that retains the commuter niceties  (rack/mudguard mounts, etc) and can handle the light gravel tracks that form part of my route.

I love the bike, but I found one fundamental problem: The cantilever brakes set off this (initially) terrifying judder under pressure. On one downhill section, I couldn't brake enough to stop accelerating without this vibration running through the whole bike (and me), massively increasing my stopping distance. As a commuter in Oxford, being able to stop quickly and confidently is a must; something I've always been able to maintain with the V-brakes I'm used to.

Back at the shop I was told that the judder is something that all CX bikes share, and that it might have been accentuated by the fact I was on a fresh bike on wet roads.  I've also read that softer shoes and toeing in can help reduce the level of vibration, but that nothing can be done to remove it completely.

So, can anyone point out a way to address this? Is it something I'd simply have to get used to, or have I just picked the wrong kind of bike for my needs?

EDIT

Thanks to 'grivooga' at Reddit (via Cyclo), this is an ideal description of the issue:

  What happened is that the fork blades and
  your headtube flexed. Just a little but enough to change the distance
  between the brake cable stop and the brake arms. This caused the
  brakes to pull harder. Something had to give, either the tire will
  skid, the brake pad will skip, or you'll go over the bars and crash.
  In this case the brake pad skipped on the rim. That released the
  pressure momentarily the frame and fork flexed back then the pad
  caught again and the process repeateded. The whole process happens
  very quickly, many times a second.

I'll try one of the recommended fork-mounted hangers, along with some better toe-in and maybe softer compound pads.

EDIT2

For future readers: After a couple of telephone discussions and a short wait, I took it out again with a fork-mounted hangar attached as shown:

The red circle shows roughly where the original hanger was situated. With the drop significantly reduced, all I feel now is the occasional soft vibration, and only when I lean fairly hard on the front brake. Enough of an improvement that I bought the bike.

A simple solution from Specialized itself to your problem could be the installation of a Tricross Fork Brake Hanger.

Here is a lengthy discussion at reddit/r/bicycling about this exact same problem with the same bike: Carbon forks flex under braking. How much is 'normal'? How easily do they fracture?