Front Brake Judder

[Mike Whitworth]

Hi Guys
I am having a similar brake problem to "Greenman" i.e. judder when braking firmly but with no pulsing of the brake lever, on my 03 1150gs with abs and only 10,000miles . So far I have checked the following .
1).I have switched the ABS off and it made no differance.
2). checked the disks for warpage with a digital vernier hand held against the fork leg not a perfect way to do it but I think good enough I could not detect any warp on either disk. BUT did notice that the wheel is off centre by 60thousand of an inch. (to the left)
3). Re torqued fork bridge bolts they were slightly loose this made a slight improvement .
4). removed and cleaned brake pads and checked that the caliper pistons are moving freely.
5). examined visualy the front shock absorber for leakage non apparant
6). checked and experimented with different tyre pressures.
7). checked the tyre for signs of damage uneven ware etc ( it is a tourance tyre with 2.5.m of tread left on it . the tyre ware is very even with no signs of flat spots , squaring off etc.
HELP
What have I missed ?? the bike handles well and under normal braking seems fine
Regards to all
Mike Whitworth.
[email protected]

 

[rocks]

Judder..

Hmm head bearings and the pivot pont/junction on the wishbone?..

 

[Mike Whitworth]

Hmm head bearings and the pivot pont/junction on the wishbone?..

I should have added
no 8 checked head bearings by graspng bottom of forks and trying to feel for any play which I could not .
would this show up play in the pivot point bearing on the wish bone ??
m new to oil heads always had airheads in the past not sure a how to check these new fangled telelever thingies !!!!!
thanks for repying Rocks

 

[Steptoe]

Try moving the discs backwards and forwards by pulling/pushing ( i.e. the same rotation as the wheel, clockwise/counterclockwise) - do they move slightly or clonk

 

[northengit]

Not a lot more you can check IMO.... however may be worth checking / cleaning the disc's them selves .... and double check fork oil quantity and type..other than that dunno.

 

[Burfcontrol]

Get off the track - there's a train a cumin !!

 

[robbie c]

Brake Judder

Similar problem, but my disc shows, an obvious section where the disc is pitted.

Im just going to change to motorworks cast iron discs.

Cheers

Rob

P.S. the more weight on the bike the worse it is, when breaking harder and alpine moutain passes were just a nightmare!!!!

P. P. S: Steptoe my missus makes a fair living out of alf and shifty!

 

[(RIP) Bin Ridin]

There is a link here somewhere to a site where the guy debunks the warped disc idea (not that you mentioned that) and explains that holding the brake on when stopped, at lights for example, when the disc is pretty hot, after stopping like the clappers for example, can deposit pad material on a patch of disc. Result - uneven stopping force as disc rotates.
Serious cleaning of the disc would be my advice - wire brush in drill, meths, blowlamp....
I think sometimes bikes are sprayed with wax which gets in the wrong places too......
Bin

 

[tonys]

I went through 3 sets of discs under warranty with the same symptoms before convincing BMW to replace the wheel as well. No problems since. My theory was that the disc mounting points on the hub were out of true.

 

[Mike Whitworth]

Brake Judder

Steptoe
I tried your suggestion re rotational movement result None at all

Tony
good point about the wheel but as I checked the disks with a digital vernier guage held against the fork legs surely this would have shown up any problems of the wheel / disk mounting inacuracies?

Bin Ridin
I think your idea about a serious cleaning of the disks is my next step

To all
please keep the ideas comming as I am getting paranoid about this problem

Thanks again guys

Regards
Mike Whitworth

 

[Burfcontrol]

Shot in the dark - try getting the wheel re balanced. Although tyre wear may look even the distibution of rubber Throughout the tyre wall will not be it's a normal effect of the process. Don't know why this would only show up under heavy braking but it's a simple thing to check. Could also explain Tony's issue where swapping the wheel fixed the problem.

Good luck

 

[the celt]

Try moving the discs backwards and forwards by pulling/pushing ( i.e. the same rotation as the wheel, clockwise/counterclockwise) - do they move slightly or clonk

Here Neil,
mines do that what it mean ???
thanks

 

[tonys]

Could also explain Tony's issue where swapping the wheel fixed the problem.

Had several tyres during the course of the brake saga ,didn't make any difference. I think you'll find the amount of runout required to cause the juddering is infinitesimal! Certainly none of the 'faulty' discs were ever outside BMW's tolerances, but could still cause enough judder to make the ABS kick in early.

 

[Mike Whitworth]

Had several tyres during the course of the brake saga ,didn't make any difference. I think you'll find the amount of runout required to cause the juddering is infinitesimal! Certainly none of the 'faulty' discs were ever outside BMW's tolerances, but could still cause enough judder to make the ABS kick in early.

Tony
interesting point about the within spec disks still making the ABS kick in but mine judders just the same with the ABS switched off.
Mike

 

[tonys]

What I meant was, the juddering was bad enough for the ABS to think the wheel was locking. The judder was there whether the ABS was switched on or not.