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Discussion Starter #1
I have the clunking in my front rotors as described in previous post that apparently is caused from the floating rotors. I was worried about it until I searched and found info on it, so now I'm OK with it.

My question is, whats the purpose of floating rotors, and wont' the holes eventually enlarge or elongate from the constant sudden force on metal to metal? I know I'm second guessing years of proven technology, but it just doesn't compute in my head.
 

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The steel of the rotors expands and contracts due to increases and decreses in heat from braking. If the rotors were rigidly mounted, the expansion & contraction would put force on other components, (forks, calipers, etc.), which can cause handling and excessive wear problems.

As to the question about the holes getting bigger: my '01, (and '95 K1100), had replaceable inserts in the holes that were made of softer material and would wear out before the rotor carriers or rotors.

Does that answer your questions?

GB
 

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Wrencher Extraordinaire
2005 K1200LT
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Most cars have fixed rotors and floating calipers. You can't have both fixed so one must float and BMW choose the rotors.
 

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Discussion Starter #4
Thanks for the responses and I'm sorry I didn't reply back sooner. I left the next morning after posting my question on a trip with my daughter and didn't get back until yesterday.

It makes since now, why the need for the floating design and I'm glad to hear about the replaceable inserts.

Matt
 

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Here are the parts and numbers from RealOEM if you need to replace the buttons, or Roll Pins as BMW calls them.

Part Price # needed Part#
02 Stop disk $1.34 5 34117670217
04 Roll pin $6.47 10 34112314887
05 Wave Washer $1.29 10 34112314888
06 Oval head screw M8X25-10.9 ZNS3 $1.93 10 36317709543
 

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Hello Matt

I have >60 K on a 99 LT and once changed the front pads and the ones I used did not have the oval anti rattle spring around the pin hole . It drove me nuts until I touched the front brake while it was rattling and it stoped . Got pads from Beemerboneyard.com problem solved .

Bob G
 
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