Help with an R90/6

[bozo100]

I have just acquired an R90/6 with a disc brake on the rear. The problem is the Anchor plate and brake calipers are missing. Can anyone supply me with a picture of the rear disc brake assembled on an R90/6. If I know what I am looking for it will be easier to find.
Thanks in anticipation of a reply.

[20774]

As far as I can tell, the R90/6 was only offered with a drum rear brake. Someone must have modified yours to accept the disk brake. Here is a picture of the parts for a late '70s R100RS with a disk brake...maybe this will help...

http://www.realoem.com/bmw/showparts.do?model=0395&mospid=47886&btnr=34_0616&hg=34&fg=10

[sumran]

Someone probably needed a wheel and used what they had or could get. Do you have a rear master cylinder and resevoir? Is your brake pedal set up for a master cylinder? I haven't seen the bike so I don't know, but given the other parts you are missing and the non-stock application, it seems doubtful.

Since you are going to spend parts money regardless of the direction you go, it becomes a question of money and trouble for the fix versus the benefit of the end result. My guess is that you will find the cost of restoring the stock drum brake is similar or even cheaper. This is even more likely if modifications need to made to accomodate a non-stock system. Many people feel the drum brake on the rear is superior to the disc. I expect you would find very few that would modify their machine and spend extra money to get a disc on the rear.

[Rod Sheridan]

I'm riding my second R90/6, and they do not have, or need a rear disk brake.

Your best bet is to go back to the drum if possible, or complete the rear disk installation.

Regards, Rod.


Actually, put the rear disk on the front, the existing front disk can use some help!:D

[crazydrummerdude]

I have just acquired an R90/6 with a disc brake on the rear. The problem is the Anchor plate and brake calipers are missing. Can anyone supply me with a picture of the rear disc brake assembled on an R90/6. If I know what I am looking for it will be easier to find.
Thanks in anticipation of a reply.

Can you post any pics of it?

[Polarbear]

A /6 with a rear disk is an abnormal bike indeed! But, somebody must have done the work for whatever reason. Its been argued many times, the drum vs.disk phenom and to somes satisfaction, I would guess. A slash 6 needs to be restored to the drum, imo and the drums work very very well if "maintained well". A good dry drum, free of debris like oils etc will perform extremely well and lock the rear end up. The biggest issue anyone has ever had with rear drums is there ineffective response in rain, or when they have been maintained poorly. The latter being the case in so many owners. The disks are rain proof, work well, but have that fluid thing to worry about! Drums are nearly equal, mechanical devices and RAIN, who needs hot brakes in rain? You'd better have a good understanding of rain and braking. Only the ABS systems of today have a good answer for this. Ride safe and keep the brakes in good order, whatever version, add on you have. Randy13233:wave