It looks like the pictures don't really go with the text.

 

I read that this morning. It seems like his answer is just a stiffer fork or smaller brake pads. The other option is tightening your headset, but I think that is fairly obvious.

Incidentally, I saw him race on Saturday and he is fast.

 

Thousands of dollars into a CX bike and there's a fundamental flaw like fork chatter?

Wow.

That doo-hickey that mounts to the center bolt hole is a very good trick!

Me? I use v-brakes.

Is there such a thing as a v-brake that is non-linear pull???

 

Is there such a thing as a v-brake that is non-linear pull???

Mini-V brakes supposedly work with standard-pull levers; I think that works for road bikes, but for cross I'd want the pads to open wider.

 

Mini-V brakes supposedly work with standard-pull levers; I think that works for road bikes, but for cross I'd want the pads to open wider.

I went to Mini-V's to eliminate shudder but I race in SoCal so mud is a non issue. I can nose wheelie my bike with one finger.

 

I might give Mini- Vs a try, but it makes me sad since cantilevers are such a symbol and tradition of cyclocross. Nothing looks better either.

I might also try drilling my fork and adding a a cable hanger to it.

I also noticed the super short pads on Richard Sachs bikes. I run cut pads, but just for fork clearance.

I use Mavic GL330 rims, which have a non-machined braking surface. The shudder with those wheels is much worse that the shudder on my machined-braking surface training wheels.

 

I might give Mini- Vs a try, but it makes me sad since cantilevers are such a symbol and tradition of cyclocross. Nothing looks better either.

I might also try drilling my fork and adding a a cable hanger to it.

I also noticed the super short pads on Richard Sachs bikes. I run cut pads, but just for fork clearance.

I use Mavic GL330 rims, which have a non-machined braking surface. The shudder with those wheels is much worse that the shudder on my machined-braking surface training wheels.

I THINK Richard has them cut for fork clearance, no chatter. Not 100% sure though, but I seem to recall that in the instructions he gave the shop to build up the team bikes.

 

I like the Zinn articles, but when things get complicated mechanically, his intuition and explanations are typically a little off (see his articles on rotational weight and that whacky company he advised? with spring loaded spokes).

Here is where I think he is missing something... His explanation would be great if the opposite of fork flex and cable "stretch" was true. If the fork flexed under hard breaking and resulted in a slacking of the cable, then you would have a nice harmonic type response leading to something like shudder shown in his picture. But this is not the case and he correctly says this in the text.

If one were to believe his theory, a fork that didn't flex at all should also have shudder but less pronounced because of his idea of brake pads losing and regaining grip - and nothing should limit this to cantilever brakes. This is like anti-lock brakes as someone else pointed out.

One logical approach would then be to analyze whether a fork flexing and pads 'breaking free from the rim' would lead to a much more pronounced shudder - the kind that makes a bike somewhat uncontrollable. This might be the case, but then his "solution" of putting the cable stop on the fork crown doesn't really matter because the 'extra' cable pull of the 'bad' setup under fork flex could be achieved by just pulling harder on the brake levers ultimately leading to the same pad 'breaking free from the rim' on a flexed fork.

Taking this a step further, a road bike with a really lightweight all-carbon fork under heavy braking should also flex and the brakepad will eventually 'break free from the rim' and cause a shudder - but this doesn't seem to be an issue with most lightweight road bikes.

Unfortunately I don't really have an answer - that's in part due to the fact that I've only thought about this for 20 minutes and I don't get paid to tell people how the mechanics of their bike works. But... I did stay at a holiday inn express last night.

 

One thing Zinn didn't mention is using a travel agent with a V brake. Works great.

Also, he's not the only fan of using a fork-mounted cable hanger:
<embed src="https://www.cyclingdirt.org/assets/portal/add_ons/mediaplayer-4.2/player.swf" width="480" height="312" bgcolor="#" allowscriptaccess="always" allowfullscreen="true" flashvars="&image=https://s3.amazonaws.com/flocasts-user-videos-images/18101_TodWellsProBike_1260481281013_l.jpg&logo=https://www.cyclingdirt.org/assets/portal/simple30/images/video_overlays/cyclingdirt.png&file=https://s3.amazonaws.com/flocasts-user-videos/18101_TodWellsProBike_1260481281013.flv&frontcolor=000000&lightcolor=cc9900&controlbar=over&stretching=fill" /><p><a href="https://www.cyclingdirt.org">Cycling Videos on CyclingDirt</a></p>

 

Regarding v-brakes, there is a reason why mtn. bikers won't touch cantis. They don't work. Too many variables to go wrong.

It's interesting road calipers, v-brakes, and disc brakes have ALL increased stopping performance over time, except cantis.

IMHO, the fault of mini-vs on cross bikes do not lie with the brakes themselves, it's the rather antiquated "low cable-pull" road levers. Increased cable pull is an essential part of a modern brake system.

 

enlightening read. i have a 2 year old ridley crossbow. front end features include: proprietary fork and fsa headset that came with the bike. no name (but i suspect tektro) mafic ripoff cantis (cannibilized off a specialized by my buddy w.). rim wrangler cartridges. gt mtb cantilever cable hanger (leftover from the 90's). kool stop black brake pads. zipp team aluminum rim. odyssey slick cable. there is no brake shudder whatsoever. whadday think? i'm considering that the brakes and fork (and maybe headset and frame) were all designed to work together?

 

I like the Zinn articles, but when things get complicated mechanically, his intuition and explanations are typically a little off (see his articles on rotational weight and that whacky company he advised? with spring loaded spokes).

Here is where I think he is missing something... His explanation would be great if the opposite of fork flex and cable "stretch" was true. If the fork flexed under hard breaking and resulted in a slacking of the cable, then you would have a nice harmonic type response leading to something like shudder shown in his picture. But this is not the case and he correctly says this in the text.

If one were to believe his theory, a fork that didn't flex at all should also have shudder but less pronounced because of his idea of brake pads losing and regaining grip - and nothing should limit this to cantilever brakes. This is like anti-lock brakes as someone else pointed out.

One logical approach would then be to analyze whether a fork flexing and pads 'breaking free from the rim' would lead to a much more pronounced shudder - the kind that makes a bike somewhat uncontrollable. This might be the case, but then his "solution" of putting the cable stop on the fork crown doesn't really matter because the 'extra' cable pull of the 'bad' setup under fork flex could be achieved by just pulling harder on the brake levers ultimately leading to the same pad 'breaking free from the rim' on a flexed fork.

Taking this a step further, a road bike with a really lightweight all-carbon fork under heavy braking should also flex and the brakepad will eventually 'break free from the rim' and cause a shudder - but this doesn't seem to be an issue with most lightweight road bikes.

Unfortunately I don't really have an answer - that's in part due to the fact that I've only thought about this for 20 minutes and I don't get paid to tell people how the mechanics of their bike works. But... I did stay at a holiday inn express last night.

You're wrong, Zinn's right.

 

You're wrong, Zinn's right.

For your amusement Rivet, I've setup my Redline both ways with the cable stop mounted in the fork crown as well as on headset. It makes no difference on this bike - there is a slight amount of shudder in both cases.

Interestingly, it looks like it might be due to how the long arms on the cantilevers flex under high load and are then twisted forward by a rotating wheel under hard braking. My guess would be that the slight twisting causes the brake pad to be a off angle from the rim and maybe this breaks its grip. This theory would match the anecdotal evidence that a short brake pad works better. If the short brake pad twists, most of the braking force will still be in the correct part of the rim. I would venture to say that in some setups the high cable stop (not on the fork crown) might exacerbate this bending of the cantilever arms. It doesn't seem to be an issue on my Redline, but maybe the setup is different on other frames.

Rivet - I'm curious as to your experiences and opinion on what causes shudder.

 

These Forkcablehangers work excellent.
Some companies in germany,like stevens, use them on there bikes, as a serial feature..
But they can kill your downtube, if you crash.

 

I had epic brake shudder with a Winwood fork and TRP cantis, and horrible squeal. I switched to an Avid v with travel agent in the front and a Frog rear canti and problems solved. Interestingly enough, both pads were longer on the new brakes than the TRP's.

 

I like the Zinn articles, but when things get complicated mechanically, his intuition and explanations are typically a little off (see his articles on rotational weight and that whacky company he advised? with spring loaded spokes).

Here is where I think he is missing something... His explanation would be great if the opposite of fork flex and cable "stretch" was true. If the fork flexed under hard breaking and resulted in a slacking of the cable, then you would have a nice harmonic type response leading to something like shudder shown in his picture. But this is not the case and he correctly says this in the text.

If one were to believe his theory, a fork that didn't flex at all should also have shudder but less pronounced because of his idea of brake pads losing and regaining grip - and nothing should limit this to cantilever brakes. This is like anti-lock brakes as someone else pointed out.

One logical approach would then be to analyze whether a fork flexing and pads 'breaking free from the rim' would lead to a much more pronounced shudder - the kind that makes a bike somewhat uncontrollable. This might be the case, but then his "solution" of putting the cable stop on the fork crown doesn't really matter because the 'extra' cable pull of the 'bad' setup under fork flex could be achieved by just pulling harder on the brake levers ultimately leading to the same pad 'breaking free from the rim' on a flexed fork.

Taking this a step further, a road bike with a really lightweight all-carbon fork under heavy braking should also flex and the brakepad will eventually 'break free from the rim' and cause a shudder - but this doesn't seem to be an issue with most lightweight road bikes.

Unfortunately I don't really have an answer - that's in part due to the fact that I've only thought about this for 20 minutes and I don't get paid to tell people how the mechanics of their bike works. But... I did stay at a holiday inn express last night.

Looks like you didn't understand Zinn's explanation. The flex he's talking about is the flex between the brake and the last housing stop. With a typical setup, the cable stop is above the top half of the headset, way high on the steerer. That's a good distance and the more there is flex between those two points, the more the cable can be pulled and/or let loose when braking to cause the shudder. Brakes can flex, the fork at it's crown, the steerer, might be some little play in the headset, alone individually, it might not be much but they can add up.

On a road bike or with a v-brake, the housing stop is part of the brake so you elmiminate the fork flex, steerer, headset... pretty much everything. Even with a flexy fork, it could bend noticably under braking but it wont change how much cable is pulled, the brake is 'isolated' from the influence of the flex further than the brake mounts. Plus a road caliper is usually much stiffer than a canti. Using a fork mounted stop eliminates a big chunk of the portion that can flex as most fork flex at the crown and steerer junction, not much between the brake mounts and the crown.

 

I have to chime in and say that I fixed my horrible brake shudder problem yesterday... with a zip tie. My shudder was so bad it actually put me off riding the bike as I felt it was dangerous.

Firstly my set-up... I have a BMC CX-1 with FSA headset. Forks are Easton EC90x, I am running Eurox Mag (2010) and Dura-ace wheelset.

I swapped the standard brake pads out to Swisstop greens and set up as much toe in as the brakes would allow (not much). I'm running my straddle fairly low, mainly as I ran it high at first but found I just didn't get enough brakes.

I tried cranking the headset, and considered cutting my pads down.. but I found the solution with a zip tie. I threaded the tie through the straddle and looped it back behind the fork. I tightened the loop so that the straddle sat back closer to the frame, but not so tight that it interfered with the operation of the brake. It made the brake line travel along the same line as the headtube.

This brings the straddle under tension towards the frame when you are braking... It also changes the angle that the brakelines travel at the brakes themselves. I'm not completely sure of the whys... but I went from having the worst shudder to none in two minutes!