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Discussion Starter #1 (Edited)
The B10 brake thread made me think of something I've always wondered about my car - maybe someone here has an answer. Is there a difference between the four-pot M635 Girling calipers and the four-pot Alpina B7 Girling calipers (as well as the rotors used for each)? Here's why I ask: with the original 16" Alpina (open lug) wheels mounted on my car, I have to use a 5mm spacer to keep the inside of the wheel face from contacting the body of the caliper. I cannot believe that Alpina designed it to need spacers. So, I have to think that somewhere in it's lifetime, some previous owner had a brake job done, and the Alpina calipers and rotors were replaced with M635's. Can anyone confirm my suspicion? (BTW, my 17" covered lug wheels clear the calipers with ease, and don't need spacers)
 

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brakes

I don't have the final answer to the difference in brakes you are asking. But I do know that there is a slight difference in early Alpina open lug 16" and the the later covered center Alpina 16" rims. I had 16" Alpina covered center rims on my e28 M5 and they cleared the M5 calipers. But I had to switch rims once with my open lug Alpinas and the open lug Alpina interefered with the M5 calipers and I have to use 5mm spacers to clear.

Again that is not the answer you are looking for but just pointing a very slight difference in the two different style Alpina 16" rims.
 

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Hi Guys,

From what I know/was told, the caliper-halves (the parts with the pistons in it) are the same between the Alpina and M5/M635CSI. The spacer between these halves is different though. Alpina used one which is 1-2mm thicker than what BMW used, also the Alpina discs seemed to be 1 or 2mm thicker.
Now that they aren't available anymore since some time, Alpina states the (same diameter) 300mm discs from the M5/M635CSI as allowed replacement. The thickness of these discs when looking at the middle-part with the 5 bores in it for the wheel-bolts (sorry, uncertain what term to use in English for that now :rolleyes: ) could be the answer to your question. Maybe a 1-2mm differ in them from vendor to vendor...?
The 'pot-depth' (if you understand what I mean) should be the same though.

Uncertain if the brake-pads Alpina initially used were different as well but also here the M5/M635CSI pads are officially allowed.
The overhaul-/gasket-sets for them are the same logically.

Cya
Rene.

P.S.
Recently saw these overhaul-sets at www.pelicanparts.com for A LOT lower price than from the dealer, maybe worth while ordering them there, even with the added shipping...
 
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