Brembo Calipers - Info Needed

[youngjohn]

Does anyone know if the Brembo callipers on an 83 R65 are common to any other BMW's or any other bikes for that matter? Also a part or model number would be great.

They look the same as my mate's Le Mans but may not be identical.

This would widen the net regarding hunting a  replacement down.

Thanks.

[nhmaf]

Brembos on the BMWs did change a little during the later 1980s, I believe, but any Brembo caliper from a similar vintage BMW should work.   The "tophat" spacers used to center them over the rotors for different model fork legs will vary, but I think the basic caliper assemblies are the same.   There are alot of interchangable parts on BMW airheads.     I am not familiar enough with the Guzzi to say for certain, but the Germans and Italians did tend to use the same vendors parts for bikes in those years for electronics, etc.

The important thing with the calipers would be to make sure that the piston size (diameter) is the same as the other one on your bike (if fitting a replacement to one side of a dual-disc front brake setup) to help ensure that you are getting even braking on both sides - the mechanical advantage being the ratio of the brake caliper piston size to that of the master cylinder piston size.

[Bob_Roller]

Problem with brake calipers, is that usually, the motorcycle manufacturer has their own part number for the caliper, they don't use the Brembo part number, so it is difficult to cross reference the calipers between bikes  .

The first issue, is the dimension between the mounting holes in the caliper they are not the same between Brembo calipers  .

The OEM Brembo calipers on the  R65, are 36 mm diameter pistons the larger bikes had larger pistons, 38 or 40 mm if I remember correctly .

So like nhmaf has stated, your master cylinder may or may not work well with different calipers with a larger diameter piston .

BMW had 3 or 4 different master cylinders with different  piston diameters, so you need to most likely to match the two, to work properly .

EDIT :  Did a search for Brembo BMW motorcycle caliper cross reference, this is what I found, hope it may help you out .

http://www.thisoldtractor.com/brembo_brembo_brake_and_clutch_cross_reference_for_bmw_motorcycles.html

From the look of the chart, the calipers on the R65, were pretty much specific to the R65 .

[youngjohn]

Thanks - that's really helpful.
Can you also tell me if the master cylinder and calliper hose threads are both M10 x 1?

[Tony Smith]

Thanks - that's really helpful.
Can you also tell me if the master cylinder and calliper hose threads are both M10 x 1?

All caliper and master cylinder threads on airheads are M10*1.
 
Do not be too concerned about the M/C diameter if you change to either multiple calipers of calipers that have a different  bore size. By the way, I dispute Bob's post regarding Caliper bore size. As far as I know, Brembo model F08 calipers fitted to the front all pre-1985 airheads were the same. In any event, if you want to fit twin calipers, just make sure that they both have the same piston diameter and all will be well.
 
There is a different bore size for the Brembo caliper used on the rear of some pre-1980 R100Rs bikes, but these are now sufficiently rare that I doubt you will ever see one.
 
The standard R65 single disc master cylinder (13mm IIRC) will work very nicely indeed with twin calipers - BMW were very conservative in hydraulic ratio.

I am not entirely sure what differences come after 1985, I do know that moto bins lists a different overhaul kit for post 1985, I also have a vague memory that BMW narrowed the front axle width around then as there was no longer the need to accomodate spoked wheels in the road models and that as a result the castings on the calipers is different so as to provide a different "centre' distance.

[Bob_Roller]

Here's a link to Motorworks site for Brembo repair kits, it states there are two different kits, one specifically for the R45 / 65, then one for the rest of the range of the twin shock bikes of the era .

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=20&Ct=HA&SbCt=BA_15_20_HA_25&spPage=3

[Tony Smith]

Bob, you are correct.

you missed an opportunity as I would have bet large they were all the same pre-1985 with the exception of some R100RS rear caliper.

[montmil]

For those sometime difficult-to-locate Brembo brake and master cylinder parts, check these alternative sites:

http://shop.bevelheaven.com/default.aspx

http://www.mgcycle.com/product_info.php?products_id=591&osCsid=b0b92b623eb248e0e2114be092c8a4e9