Brake Vibrations

[duggiesmith]

After the TT 2012 trackday, I noticed a bit of a knocking noise when applying the brakes.
This has gradually got worse and there is a definite vibration felt through the steering wheel when braking from higher speeds.
New disks and pads were fitted ll round about a year ago and have done 3 trackdays since then (although most of these were spent chatting rather than driving )
Any suggestions to what my be causing it?
Other than the knocking and vibration, the brakes feel OK.

TIA

[Shug]

Warped/build up on the disc. Can happen if you park up with them hot and put on the handbrake, or just from uneven pickup from pad to disc (which becomes worse when the buildup starts as it's a viscous circle)

If it's bad enough, worth getting runout checked on the discs, which on the S2 (with the wee disc locating screw) you could do DIY with a magnetic stand and a dial gauge, methinks...

[philthy]

wheel bearings too possibly

[Shug]

True - is it *only* on brakes, or is it still there (albeit a lot less evident) without the brakes on?

[Rich H]

Rough loving time?

slow from 70 to 10 mph hard without triggering ABS a few times* and see if it gets better.
Can hel;p even out the disc surface. If you get it right you'll smell hot brakes....



*clearly on your private road

[duggiesmith]

Thanks guys.
Just seems to be when applying brakes, so Shugs diagnosis seems most likely.
My technical capabilities are limited at the best of times and when it comes to brakes I'd rather trust the professionals.
Booked in at MMC on Friday. Fingers crossed.