Front wheel and brake disc mountings.

adrianw · adrianw's Garage

Hi,

More long term abuse bad news I'm afraid,

For the past 10,000 miles two different dealerships have suggested that my discs are warped. However the left hand disc (looking at the bike front the front) had a lot of play ie it could rattle about a lot, unlike the right hand disc that seems fixed.

So I ordered a set of cast iron PFMs discs, new pads, rollers, top hats etc. Then armed with a seven series jack, a garage wall, some loose bricks and a few planks of wood...I removed the front wheel.

I then removed the rattling disc to find that the 'stalks' that the disc are mounted to had been eaten away by the free play in the disc, leaving about a 1mm raised platform on the stalk, which matches perfectly with the profile of the roller. The second disc / stalks however have no symptoms.

At the 48,000 mile service (@75,000 now), my original disks were replaced as they were below tolerence, and due to BMW having run out of disks at the time we had to fit a set of EBCs. At the time BMW were also out of rollers/top hats. So they refitted the old ones.

So, Questions:

Is my front wheel *****ed because :

a. Re-use of the old rollers/top hat.
b. Fitting EBC discs.

Is it fair that I have to pay for all this, when it was all done through the dealer network?

Bugger.

Adrian

Firebolter · 08-24-2002, 12:42 PM

I had a similar situation with my 88 Honda Prelude. Dealer said, not my fault and your car is out of warranty, so I drafted up a nice long, factual and very descriptive letter and sent it to American Honda. In your case I guess you would send it to BMW corporate in Britain. ANyway, I got a letter back from them that told me to take it to the dealer and it would be fixed to my satisfaction. While dealers should do the right thing, sometimes they need pressure from above.

If you have copies of the reciepts and dealer work, copy them and send them in with your letter. It will help support your story. Be very polite but firm. Tell them you did what the dealer suggested, even though the BMW parts weren't available, YOUR BMW dealer recommended the use of other than OEM parts.

It might work, did for me.....Good Luck

GUS · 12-17-2003, 08:02 AM

Adrian and anybody else who has this wheel post wear.I am trying to get some kind of goodwill warranty claim concerning this disc mounting wear problem.As i see it,the later models 2000 onwards have an extra spacer fitted along with the tophat,bolt,wavey washer.Pre 2000 models do not have the spacer.Why?Did BMW have a problem?These are some of the questions i would like answered before i take the matter further.I have gone to my dealer,who then sent a report saying i needed a new front wheel.They replied NO,because my bike does,nt have a full dealer service history.What this has to do with the knackered wheel,god only knows.So let me know if any of you have had this problem and how you got on sorting something out.My bike had 38000 when the problem was really noticable.
regards gus

Raven · 12-17-2003, 08:21 AM

I had a 1991 K100RS eat up the rollers at about 50K miles. I replaced them before they damaged any thing else around them. The disk were fine and required no attention.

I have a hard time understanding why they would even consider putting worn out parts back on your bike. Waiting to get new parts instead of running the risk of further damage to the bike would some how seem far more prudent.

GUS · 01-15-2004, 01:35 PM

Just to update people on what happened regarding my problem of front wheel wear.Having spoke to BMW GB a few things came to light.
1. they do realise that early bikes have a problem pre 2000 models.
2. they didnt issue a recall because,its not dangerous.
3. because i didn,t support the BMW network by having my bike serviced by dealers or buying extended warranties,they told me to basically get lost!
Well as you can imagine i wernt to pleased and told them so,all to no avail.
Anyway have now fixed problem by inserting very thin washers between disc and wheel.Result no more rattly discs,and discs still float.A side effect of this has been that the brakes dont squel like they used to when coming to a halt.Result i reckon.Have any of you guys had problems like this.Quite a few people in the uk have.
gus

jclark · jclark's Garage

Would replacing your wheels w/current ones solve the problem the same way?

jeff

GUS · 01-16-2004, 01:52 AM

Apparantly wheels are still the same,they have just changed how they are mounted.Extra part which sits between wheel and disc.So putting on the new mountings should solve the problem.The problem shows up on bikes with about 30,000 miles on them.Guys with 2000+ models have run to 70000 with no probs as yet.
gus

jclark · jclark's Garage

I'm not sure ours ( wheels ) require the same hardware you're talking about..

jeff

adrianw · adrianw's Garage

Hi,

After 136,000 miles it has happened again.

The disks have eaten into the stalks of a second wheel.

Got a new second hand wheel on the way, with the old PFM disks being replaced with EBC disk pads etc.

Wheels - The are a wear item, get used to it.

Regards,

Adrian
R11S 1999 136,000 (2 cylinders)
R12S 2006 31,000 (2 cylinders)
K1 1993 30,000 (4 cylinders)
730i 1989 195,000 (6 cylinders)
750i 1997 122,000 (12 cylinders)

That just leaves a single (BB1?) and a triple (new 675?)

Sideshow_S · 10-21-2008, 03:02 PM

136K KM or Miles?

I've 95K miles. Not a single issue with the front brakes on the '99. Amazed that the original pads lasted 65K. I think you are doing something wrong. Maybe the shims are to go onto the brake caliper mounts and not the wheel? As in your fork mounts have the wrong offset (bent?) causing the rotor to require warping to conform to the position of the caliper. (?)

adrianw · adrianw's Garage

Miles honey.

Sideshow_S · 10-22-2008, 04:43 AM

Nice! But please, call me hun.

adrianw · adrianw's Garage

Hi,

I was down the garage today, and this time it's on both sides, but the left hand disk (looking at the wheel from the front) is a lot worse.

I'm wondering about the cast iron discs I've been using, maybe they are too 'hard' on the stalks.

Regards,

Adrian

jduke · 10-22-2008, 11:53 AM

Nothing big here adrianw, but you generally refer to sides sitting on the bike, facing forward. (not sure the last part needed, but with this crowd you never know)

motoyoyo · 12:23 PM

adrianw, a while back I mounted up some Braking wave rotors to my stock wheels. I used some stainless steel shim washers underneath the rotors and on top of the aluminum posts. This was mainly to give more float to the rotors, allowing the wave spring washers to have some more play. It would certainly also serve to isloate the rotor from the aluminum mounting posts as well. Other sizes could work but this is what I used:

18-8 SS Precision Shaft Spacing Shim
.016" Thick
.313" Id
.500" Od

-Edit- I just realized that the shims were underneath the mounting bolts and not isolating the rotors from the aluminum posts. I suppose you could always try a larger OD shim washer but I'm not sure what sizes they come in.

chris846 · 10-22-2008, 01:34 PM

the 'shims' that you've described work fine - I used cheap 8mm oversize ss washers, sandwiched between the bobbin and the ally post. 'Normal' washers like these are within a thou or so consistency, but it wouldn't hurt to check them anyway. The big fault here is BMW's design of early bikes - the ally post corrodes & wears. The wheel posts need truing up anyway & this would enable you to salvage your old wheel. The rotors need to run as true as you can get them; discs running even slightly out of true can cause brake drag, excessive lever travel, overheating & warped discs - all bad!

markjenn · 10-22-2008, 06:27 PM

Has everyone who is having problems been using aftermarket rotors? I've seen some extremely loose tolerances in aftermarket brake parts, including EBC parts. I tend to go strictly OEM on brakes.

- Mark

throttlemeister · throttlemeister's Garage

When you get bolts & bobbins these days, it includes a washer to be put between the wheel post and the disc. I think this was a modification from the original design and it prevents the wheels getting damaged as described.

chris846 · 10-22-2008, 10:45 PM

i have pfm aftermarket narrow track rotors & carriers - they run true with no noticeable brake drag after 18 months of use. It's important to know that 'floating' rotors aren't an excuse for sloppy installation or misalignment: the rotors float because, being so skinny, they couldn't cope with the heat without plenty of 'room to move'. Heat is the killer, that's why it's best to reduce drag as much as possible.
The early R1100s, with its crummy ally posts, is a good example of a bad aftermarket installation just waiting to happen - it's not just a case of swapping bolts (like the manufacturers would maybe have you believe!)