brembo caliper- which one?

[steven m]

Adding a second disc to my 83 standard R65 and am running into a lot of differing info on Brembo calipers.  I'm getting used to BMW parts catalogs that list items for "All Airheads" and then in brackets have "except for R45 and R65", but still a little confused.  As I understand, and have been told, most Brembo calipers will not mount to our fork legs because the bolt spacing is unique, but when I hold an older double bleed Brembo caliper up, the bolt holes SEEM to line up.  What gives?  I've also seen F08 calipers, brand new, online for under $130.00 that look just like the caliper on my bike, meaning single bleed, as seen here:

http://www.accu-products.com/brembo/brembo-oem/front-brake-38mm-p2-f08-caliper-left-front-of-fork-f08-replacement-caliper-black-brembo-oem/prod_21890.html

Is this not the correct caliper?  Certainly a lot less expensive than even a decent used one.

Thanks

Steve

[Lucky_Lou]

Mine is a twin ATE (79)they look the same to me whats the hole centers on the mounting...do they match up, also are you changing the master cylinder i think the twin has a bigger piston than single should be 16mm vs 13mm i beleive.
Lou

[Bob_Roller]

Did a little research for Brembo calipers, and here's what I came up with .

The caliper number you have pictured, 20.3556.41, is a right hand caliper for a K75 .

The Brembo part numbers for R65 use, and these are Brembo  numbers, not BMW numbers .

Right caliper : 20.3681.11

Left caliper : 20.3682.21

Found these numbers on the following website :

http://www.thisoldtractor.com/gtbender/brembo.htm#bmw

From the looks of the chart, that caliper is pretty much R65 specific .

[steven m]

Wow, Bob, that is some chart!  And yes, the R65 caliper does appear to be numbered very specifically, yet the caliper for the standard R65 is listed as a right hand caliper, when the single disc models were on the left fork leg.  I also did some research, called Brembo and they suggested speaking with Fred at YoYoDyne, which I did.  The caliper mount flange holes are 108mm center to center, and the distance from the inside of the mounting flange to the center of the caliper, and disc, is 19-20mm.  If those match up, then I'm hard pressed to figure out the difference in the calipers besides the numbers.  I guess I'll do some measuring and let you know what I come up with.  Just seems odd to me that BMW could get Brembo to make a special caliper for their lowest priced bike, which as we all know ended up being the best Airhead made.

Steve  

[rl900]

I have a couple sets of F08 Brembo calipers as well as an '82 Ducati 900 SS bevelhead that has F08 calipers.  In addition my R65 has dual ATE calipers.  

Last summer I compared the F08's to the ATE's and it appears that the F08's will bolt up and work.  However, I believe there are two differences between the Ducati/Moto Guzzi F08's and the BMW F08's.  The Ducati/Moto Guzzi and K75 F08's mount ahead of the fork, while the R65 mounts behind the fork.  If you mount Ducati/Moto Guzzi/K75 calipers the word "Brembo" will be at an angle, where they will be level when mounted ahead of the fork.  The R65 F08's have the word "Brembo" level when behind the fork.

The second difference I saw was the Ducat/Moto Guzzi F08's are thread tapped where the R65 has the fork leg tapped.  You would need to drill out the threads on the Ducati versions.

Internally and dimensionally all the F08's are the same.

[Bob_Roller]

When you finally find out which caliper(s), will work on the R65, make sure you posy them, so if someone wants to add the second front discs, they have an alternative to OEM prices, or worn out used calipers .

[Mike V]

I find this link interesting. And wanted to get a question out to all of you. I also have a 81 R65 with twin ATE' calipers, although only the right side caliper is fitted with 2 caliper attachment spacers while the left caliper is not.  Is this application the same for the Brembos? And does anyone know the reason for the right side ATE' caliper spacers while the left does not? Curious if those of you with Brembos have the spacers on the right side.

Here's a picture of the (right side only) spacers lying in-between the ATE' caliper halves during my brake rebuild.

http://i428.photobucket.com/albums/qq8/gruntyman66/81%20R650%20Restoration/Front%20Brakes%205-09/81R65RestorationFBrake05-24-09002.jpg

[steven m]

Yes, this IS a very interesting thread.  Did my measuring and sure enough the dimensions are all the same as per previous posts.  My spare double bleed caliper does not have threaded mounting holes so I assume it was originally from a BMW.  As for the spacers, I have no idea but have heard those inserts are standard.  Or not?  I assume they fit with the flange between the caliper and the fork leg.  I wonder if the threaded mounting holes on the Italian bikes' calipers could be inserts as well?

Any used BMW R65 Brembo calipers are going to be at least 25 years old and probably should be fully rebuilt at this point to be safe, so when you factor in all the parts, if you need pistons, and the shipping, a new caliper starts to look cost effective.  Two new calipers, with pads, for the price of a used caliper makes sense to me.  Of course, you miss the fun of rebuilding the old ones...

Steve

[Bob_Roller]

The flanged spacers, center the caliper over the disc .

The are about 5 or so different thickness flanges, so I guess you need to install the caliper, and see how it looks, before ordering what will work for your application .

[DgM]

I ordered a complete set of caliper spacers from Irv Seaver BMW, found the correct ones for use, returned the others for a refund.  Easy.

[steven m]

Well, I'm cooking up a big pot of crow.  Just got two early 80's BMW Brembo calipers, in great shape, ready to bolt on, super clean, and... they don't fit.  The hole spacing for mounting is way off.  So much for the Brembo 'experts'.  I'm going to have dig into this a little further.  I still can't believe Brembo made a special caliper for the R65.  But then, I have been wrong before...

Ugh

Steve

[not-so-fast-ed]

Welcome to the world of "The Kleine Boxer".  Always something a "little different".....

 [smiley=cowsleep.gif]