Caliper Knocking
Whats going on here 
Its not the wheel bearing as iv had both calipers off and the wheel spins freely, no notches, right hand side caliper attached, spin wheel, its fine, add left hand caliper into the mix and this happens. Most annoying whilst riding around town.
I have replaced all seals and bleed the lines though i think one of the pistons is still sticking.. when i apply the brakes i have full braking power and no noises of judder. just when i release the brakes then this constant knocking noise seemingly every wheel rotation.
Video link:

Its not the wheel bearing as iv had both calipers off and the wheel spins freely, no notches, right hand side caliper attached, spin wheel, its fine, add left hand caliper into the mix and this happens. Most annoying whilst riding around town.
I have replaced all seals and bleed the lines though i think one of the pistons is still sticking.. when i apply the brakes i have full braking power and no noises of judder. just when i release the brakes then this constant knocking noise seemingly every wheel rotation.
Video link:
I don't think my rotor is warped, but then again i wouldn't know how to tell. I don't get any adverse feedback when my brakes are engaged, i get no pulsating feeling or noises when braking that are associated with warped rotors. Only when the brakes are released do i get this clunking noise
one way to tell is to elevate the wheel so it spins freely, then tape a pencil or marker to your fork leaving the point just a tiny fraction away from the rotor. then slowly rotate the wheel. if the pencil/marker leaves a mark anywhere on your rotor, then your rotor is warped.
Seems like your caliper may be dragging. The wheel should spin easier than what it appears to be. If the pads are grabbing to rotor, they could move the callper and make the clunk in the pins/slides. It seems to make it when the rotation changes speed.
Iv narrowed it down to just one part of the rotor that the knock and resistance happens at, its more prominent when the wheel is moving slower and less so when the wheel has some speed to it. Whilst riding though it is always there.
I can't watch the video, so maybe it's on there, but is there any strange/odd scoring on the backside of the rotor? Surely, if its dragging, there will be evidence.
Last edited by Conrice; Dec 19, 2014 at 07:35 AM.
Hi bud when I had a similar noise on the same caliper on my bike (95 f3) my top pad spring was missing and it allowed the outer pad to tap on to the caliper body.
Also, when rotating the wheel look to see if the caliper body is moving inwards and outwards (that's a sure sign on a warped rotor). You could check the space between the rotor and the caliper body at the point when you get the tap noise to see if that's causing the problem too. How are the bobbins on the rotor too you should be able to turn them - a clean with some wd40 could help a little.
Hope you sort it bud
Also, when rotating the wheel look to see if the caliper body is moving inwards and outwards (that's a sure sign on a warped rotor). You could check the space between the rotor and the caliper body at the point when you get the tap noise to see if that's causing the problem too. How are the bobbins on the rotor too you should be able to turn them - a clean with some wd40 could help a little.
Hope you sort it bud
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