Warped Front Disc

[rob1964bike]

I have done 2800 miles on my 08 GS. After long ride in rain I had stuttering feeling through lever on front brake. On checking I believe my discs are warped. Anyone else had this or heard of this on such a new bike?

Rob

 

[Schtum]

Yes, it's not that uncommon. My '04 bike suffered the same thing at 3K miles. Discs and pads were replaced under warranty. No problem with my '07 bike so far.

FWIW, I think it's related to using fixed four piston calipers without fully floating discs. Ducati Multistradas use the same calipers and discs with the discs mounted in the same way, ie onto mounts on the wheel rather than onto disc carriers and they suffer from the same problem of warped discs.

 

[Funners]

Yup, my 07 GSA had the same thing at 1800 miles...AJ changed both discs under warranty no trouble at all... been fine since...

 

[Account removed]

I have done 2800 miles on my 08 GS. After long ride in rain I had stuttering feeling through lever on front brake. On checking I believe my discs are warped. Anyone else had this or heard of this on such a new bike?

Rob

It may be your rear disc, it was on mine.

 

[orca the porker]

Yep me too, dealer sorted no probs !!
ORCA

 

[DWJ]

Yep, just had both front discs and pads changed on my 08 GSA all under warranty

Doug

 

[Deleted account 210609001]

I had a loan bike not long ago with what I thought was a worn front disc. I measured the run out and it was all ok, but I couldn't understand why there was a vibrating lever and "stuttering" braking at low speed.

Turned out the rear disc was warped enough to see with the naked eye.

 

[Funners]

I had a loan bike not long ago with what I thought was a worn front disc. I measured the run out and it was all ok, but I couldn't understand why there was a vibrating lever and "stuttering" braking at low speed.

Turned out the rear disc was warped enough to see with the naked eye.

bet that was actually the rear hub carrier....cos my rear disc moved enought to move the caliper and yet the disc was true...the carrier was not..
replaced under warranty..

 

[Dave Ford]

I have done 2800 miles on my 08 GS. After long ride in rain I had stuttering feeling through lever on front brake. On checking I believe my discs are warped. Anyone else had this or heard of this on such a new bike?

Rob

My 07 1200 GSA is in for EWS (second time!!!!) and new front discs. The scandalous thing is that, after 10,000 miles, BMW class warped discs as "normal wear and tear", so not covered by warranty. In the 21st century, is it too much to expect something as simple as a brake disc to last more than 10,000 miles?

 

[rlmr]

Surprised at your dealer's attitude.

Just returned to the GS fold after three years of the K1200S (brilliant sports tourer). However my 1st S had three sets of front discs and a new set of front callipers in 18,000 miles... my 2nd S was on its second set of (3) discs by the time I changed it for the GS.

Sure the warping was due to fixed discs and fixed callipers... have been assured the GS, with floating discs, will not suffer the same fate. BTW both S bikes were still on their original pads with hardly any wear. I would have accepted the warping if I hammered the brakes every time I used the bike, but this is not the case. Insider at BMW suggested it was the EU drive for recycling as this forced BMW to used recycled stainless steel in the discs so they were not as pure / good as earlier discs. Not sure about this, but certainly the material was sh*t compared with the old BMW quality.

Anyway I think I would be pressing the dealer hard if they suggest warped discs after 10,000 miles... albeit my S discs were shot after 6,000 miles.

Wish you the best and certainly hope warpped discs are a thing of the past with my new bike.

 

[ebbo]

Read about it here http://www.ebbo.org/front_brake_fix.php mine were fixed FOC

 

[AdamA]

My 07 1200 GSA is in for EWS (second time!!!!) and new front discs. The scandalous thing is that, after 10,000 miles, BMW class warped discs as "normal wear and tear", so not covered by warranty. In the 21st century, is it too much to expect something as simple as a brake disc to last more than 10,000 miles?

Go back and point out that unless they are worn down to their minimum thickness they are well outside "fair wear and tear" as laid down by the manufacturers own figures, so should not have warped.

 

[Daffy]

I would agree, I have had my front discs replaced under warranty twice in 17,000 miles.

I understand that there is a BMW service bulletin on the subject and theat the '08's have a modified mounting bobbin arrangement that has supposedly now been fitted on my '06.

Symptoms were heavy front end vibration when slowing from speed especially in warm weather.

Just replaced my rear pads at 17k miles, fronts never worn as changed with discs at 6k & 16k miles.

Ask your dealer to check with BMW.

 

[Jon P]

In my experience BMW have had this 'issue' for years. I first had it on my K75RT back in '93, then an 1100GS in 94, and recently on my 07 GSA. In the meantime I have had seven others (mainly GSs) that have been ok. It does seem strange though that this should be a problem in the first place and especially so that the problem has been there for so many years.

 

[ebbo]

In my experience BMW have had this 'issue' for years. I first had it on my K75RT back in '93, then an 1100GS in 94, and recently on my 07 GSA. In the meantime I have had seven others (mainly GSs) that have been ok. It does seem strange though that this should be a problem in the first place and especially so that the problem has been there for so many years.

I agree, they have had this problem for years, this is BMW analasis of the problem.

".June 2007 BMW Motorrad America issued Service Information Bulletin Ref 34 003 07 (34) Under 'Details' is the follow comment:

A combination of unfavourable tolerances of brake disc, front wheel and ABS sensor ring and/or incorrect assembly can result in an increase in runout of the front brake discs. When the motorcycle has covered a considerable distance (empirical data indicates approximately 5,000 to 12,500 miles), very shallow recesses are worn into the brake discs. The effect is perceptible to the customer as pulsating brakes, and is particularly noticeable under gentle braking."

The first proper fix was to replace the wheel and discs, now they have new retro fit floating discs.

 

[Deleted account 211025001]

Had mine replaced at 6,000 miles under warranty, along with different mounting washers (to allow the discs more movement?).

AT 32,000 miles they were warped again so I've replaced them with Steptoes discs as I couldn't be arsed to argue the toss with WMB and really just wanted a permanant solution. Steppers discs seem more substantial and are marginally thicker than the WBM ones so we'll see how they go

As an aside, I still have minor pulsing through the bars so will shortly be ordering a St. Eptoe rear disc as well

Andres

 

[BBB61]

The scandalous thing is that, after 10,000 miles, BMW class warped discs as "normal wear and tear", so not covered by warranty. In the 21st century, is it too much to expect something as simple as a brake disc to last more than 10,000 miles?

BMW class discs that have worn down to minimum thickness in over 10000 miles as fair wear and tear, but if the disc has warped they will sort it out. That is what my dealer told me. I did have a rear disc that was worn after 15000 miles. The dealer advised me to write to BMW and it was replaced as a "goodwill" gesture.

 

[ebbo]

As an aside, I still have minor pulsing through the bars so will shortly be ordering a St. Eptoe rear disc as well

Andres

Can you feel any pulsing on the rear foot brake pedal? If not, it’s likely to be re-emergence of the front disc problem.

 

[Deleted account 211025001]

Can you feel any pulsing on the rear foot brake pedal? If not, it’s likely to be re-emergence of the front disc problem.

I had very severe pulsing which was 95% cured by fitting new front discs (400 miles ago).
However it's still there (all be it much reduced) so I'm assuming my rear disc is shot. There is quite a severe lip on it so it'll want replacing in the not too distant future anyway.

I don't use my rear brake (via the foot pedal) as I have a metal leg - 'spose I should get somebody else to ride it and let me know what they think ......

Andres

 

[ebbo]

I had very severe pulsing which was 95% cured by fitting new front discs (400 miles ago).
However it's still there (all be it much reduced) so I'm assuming my rear disc is shot. There is quite a severe lip on it so it'll want replacing in the not too distant future anyway.

I don't use my rear brake (via the foot pedal) as I have a metal leg - 'spose I should get somebody else to ride it and let me know what they think ......

Andres

Its unlikley to be the front's yet then, and the rear does sound well worn...

I would ask someone else to try it though,