The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Armen on April 11, 2013, 07:44:07 PM

Title: 4 pot calipers onto a '79?
Post by: Armen on April 11, 2013, 07:44:07 PM

Anyone try fitting the late model (K or oily) 4 piston calipers onto a '79 era R65? Prob need to up the master cylinder size (12 mm now).
Bracket sources? Drawings? VooDoo incantations?
Not asking permission, only information.
thanks,
-Armen

Title: Re: 4 pot calipers onto a '79?
Post by: Bob_Roller on April 11, 2013, 11:47:49 PM

One of our members here, Julio in the Philippines attempted to get a later model K series caliper to work on his R65, best as I can remember, it didn't work out, too much metal had to be removed to get the caliper to fit on the lower fork tube .

Send him a PM, he can fill you in on it .

Title: Re: 4 pot calipers onto a '79?
Post by: steve hawkins on April 12, 2013, 02:07:36 AM

Perhaps some sort of adapter plate is required.

My brother has a 6 pot Harris brake fitted to his R100GS.  Seems to work ok.  But then it was the correct fitment.

Are you running a single disk?

The normal route is to improve the dual disk set-up with stainless lines and after market disks, etc.

On my 79 I am running a single Brembo and a floating disk.  Not as powerful as a dual disk set-up, but I have grown to like the progressive nature of the brake.  I had to change my master cylinder, from the round ATE to a later rectangular Brembo type, but still keeping my twin pull throttle.  A little bit of fettling required but not a lot.

I am also running banjo connectors, as I used to run two calipers using only two hoses, one from the master cylinder to the right caliper and the other from the right caliper to the left.  I did away with the front brake light switch.

However a single 4 pot caliper would improve braking without increasing the unsprung weight much - i.e. having the extra disk and caliper on the front wheel.  

How much volume of fluid does a 4 pot K series caliper require as opposed to a Brembo two pot caliper?  Just curious.

I am interested in this.

Cheers

Rev. Light

Title: Re: 4 pot calipers onto a '79?
Post by: nhmaf on April 12, 2013, 10:53:43 PM

Somewhere I seem to recall seeing a project that fitted a 4-pot brake (may have been from another bike, possibly Suzuki) to an 80s airhead.... gotta see if I can dig it out of the bookcases..

Title: Re: 4 pot calipers onto a '79?
Post by: Armen on April 13, 2013, 06:58:41 AM

Thanks. Just bought a couple of different ones on Ebay. I'll do a little eyeball-o-metrics and see which one will fit better.