FRONT DISCS WARPED

[BlueBird]

Got a judder on the brakes,
measured the runout and it's going up to 0.007mil,
anyone know the maximum permissble?

 

[nedflanders]

Have you tried cleaning the discs yet?

 

[BlueBird]

NO

Does it make a difference?

It got massively worse towards the end of a 3k tour.

Im not known for cleaning bikes either

 

[pikeydave]

Have you tried cleaning the discs yet?

Seeing as the bloke has measured the runout, I'd doubt a tin of brake cleaner will reduce it....

BM did a replacement set of discs and mounting bolts to cure the prob. I only warped my originals charging down from Mt Cenis chasing the Italian locals.

 

[Magwych]

0.007mm = 0.000275".

That's a very small difference, what are you using to measure to that degree of accuracy?

IMHO I don't think that they come out of the factory machined to that tolerance...

Perhaps you mean 0.07mm, or 0.7mm

 

[BlueBird]

Oops!!

Ive put to many zeros in,0.07

anyway here we go,used a dial gauge that was recently calibrated.


http://www.youtube.com/watch?v=IT6VvE23t78

 

[Monty]

I have been suffering similar juddering issues, and have had no success with my local dealer. Next stop BMW customer service to see if they are interested.

The dealer told me the tolerance is 0.15mm, so on the face of it yours will be within spec and not replaced. One of mine was 0.1 and the other 0.15 .

Matt

 

[Slowdown]

At the risk of sounding like a stuck record I find any judder goes away on mine after I give the calipers and pistons a really good clean and make sure the pistons aren't stuck.

 

[BlueBird]

Welly

I had a mild judder at about 15k and the bike was just about in warrenty so I had a new pair fitted (the second pair under warrenty),
if I would have had to paid I wouldnt of changed them then,
anyway i ve had a mild judder for the last 20k or so,but now if I go steaming into a corner and have to brake a bit hard its really bad now shaking my arms and the front wheel feels like its doing a figure of 8,
I have checked all bearings and torqued all bolts to correct setting and yes although the run out is not that much I cnt think of ant thing else it could be.

I ve fitted an EBC rear and that seems to be performing well, Steptoe has some of these as weel as some wavy one for £70 each so I may try some of these.

The bike has 52k up it.

 

[mr badger]

I have been suffering similar juddering issues, and have had no success with my local dealer. Next stop BMW customer service to see if they are interested.

The dealer told me the tolerance is 0.15mm, so on the face of it yours will be within spec and not replaced. One of mine was 0.1 and the other 0.15 .

Matt

When mine were on the way out they were measured at below the tolerated level.

I did a one day bike handling course and thrashed the brakes. Once they're a bit warped, a few really severe sessions on the brakes will see them off.

result - new set of discs and pads courtesy Mr BMW.

 

[Monty]

At the risk of sounding like a stuck record I find any judder goes away on mine after I give the calipers and pistons a really good clean and make sure the pistons aren't stuck.

I think that is sound advice. Alas, I cleaned my calipers and discs and no improvement. I also bought some Ferodo pads from Mr Steptoe and still the judder persists. I will badger BMW and also keep an eye on it over the next few months, and I may well buy some after-market discs if BMW will not budge.

Cheers,

Matt

 

[nedflanders]

I only say clean the disc's because it cured my ill's. really fine wet and dry with some spray on brake cleaner took all of 20mins to do both sides of the front discs. If it's out of warranty it may be worth a try; not much to loose, different pads might improve the situation as I'm sure pads 'go off' at a certain point in there life