Brake judder (discs)

jozi

Recently started to get some brake judder when braking hard. I put new pads (organic) on a few days ago thinking it might have been worn pads. It's still there and the pads werent to badly worn. On top of this I also started to get a bit of noise when braking although this might be down to the compound?

Anyone got any idea's? Is it normal? I thought maybe the headset was a little lose but it was fine, there's seems to be some movement in the front shocks. Also started doing the same with the rear discs earlier this evening Appart from the judder they still work extremely well!

Seems to happen mostly with sudden hard braking, if I feather the brakes and squize them harder it's less likely to happen.

Single Malt

There is always vibration when braking. The judder happens (usually) due to the frequency of that vibration resonating weirdly between frame/fork/caliper.

I take it, since no power loss, there is no contamination of the rotor.

How new are the brakes? New brakes need to bed in, and this process can cause squeals and that judder. This should disappear after a while (mucky rides speed up the process, as muck has grinding effects, and bedding in is a wear process).

Try sintered metal pads. Try rubbing the rotor with emery paper. Make sure the rotor is tight (5ish Nm for 6bolt, 35-40Nm for centrelock). Make sure the caliper is tight, 6-8Nm. Check frame/fork for damage/cracks. Make sure the QR is sufficiently tight.

Try the above suggestions and good luck

jozi

I had to sand down the rear disc lightly because it just wasn't gripping it. I've got the bike probably a year now, close to it anyway. Tha pads are a few days old, less than 100km cycled with them.

I'll check what ever alan key bolts there are before heading to work this morning. I don't think there will be any damage from abuse as the bike has never gotten any, it's pretty much being used as a road bike since I got it.

EDIT: Pretty sure the old pads were sintered but it also did it right before I changed them. The rears never judered with the old pads but that might be down to a contaminated disc (I hardly worked).

zil

Judder is usually due to very small buckles in the rotors caused by warping when the rotors get very hot. If you've been doing long descents where the rotors are burning up it's not unexpected that you might suffer from judder in the future.

You could possibly look at getting floating rotors, they have a bit of side to side play in them which compensates for small amounts of warping. But if it's not bothering you too much then it's not really something to worry about.

Pigeon Reaper

It's a buckled disc. This happens on motorbikes too. You can keep using the disc if it's not too bad but it does affect the performance of the braking. The only real solution is to replace the disc.

jozi

Same as with a car then.

I've not done any long decents of any kind with this bike. Since I've bought/owned it I've only been able to use it around Dublin. I do tent to cycle as fast as my legs will let me and brake hard most of the time, not sure to what extent that might have anything to do with it.

There's a slight bit of rubbing when spinning the wheel but no obvious bends in the disc.

Would it have anyhthing to do with there being the tiniest bit of play on the axle? The bike hasn't ever been sent back for the initial checkup, everything was fine and anything that needed looking at was fixed by myself. There's no play that I can feel in the front wheel over the axle.

There isn't by chance anyone around chapelizod who could have a look or compare with their bike?