R75/5 front drum brake springs

[Sefton]

I inherited a 1972 R75/5 that my father used for the last 20 years as his winter commuter with a sidecar. I took the sidecar off and am slowly going through things. I can't seem to get the front brake pads to touch at the same time. I pull the lever and feel one bad start rubbing but it then takes the rest of the pull to engage the other pad.

I pulled the thing apart and it feels like one of the springs is much stronger than the other one. Does anyone have any knowledge with this? Are they supposed to be different strength springs?

 

[20774]

As I recall, there are different springs, number of coils, etc., so yes they are different. Have you read Duane's section on adjusting the front brake lever:

http://w6rec.com/duane/bmw/brake/

And welcome to the forum!!

 

[Sefton]

Thanks! This is exactly the article I needed to read. Thanks for the help!

 

[lmo1131]

it feels like one of the springs is much stronger than the other one.

When/if you disassemble the front brakes be sure to label the positions of the two springs; the spring wire is of two different diameters. Also, before you remove the brake arms, put a little punch mark on the brake actuating shaft(s) directly opposite the the "slot" in the arm where the pinch bolt is. This will assure that you "clock" the brake arms in their correct (assuming that it is currently correct) positions. But all that's covered in Duane's write up.

Sidecar, eh? What make rig is it?

 

[Sefton]

It's a Velorex sidecar. Many miles on it, needs some work before this winter in Vermont.

 

[lmo1131]

Sweet.

Keep in mind that the /5, and on, frames weren't intended for sidecar duty; the frames are two-piece (as opposed to the welded-solid battleship-grade construction of the earlier models). "Flying the chair" isn't really a good thing to subject the /5 to, but it's definitely a good thing to learn how to control. I'd practice it with the chair unloaded, or at least with reduced ballast on board.

You may want to consider a DMC Sidecar Mount assembly; they spread the load out over the entire frame, which removes some of the localized stresse on the /5s rear subframe. Not a necessity, just a suggestion. Make a routine of checking the sub-frame bolts, the triple tree clamps, and the head bearing nut.

This one is for a /6 (long wheel base), I'm not sure if DMC fits the SWB/5 (I can't tell from you photo if yours is a short wheel base model).

 

[Sefton]

thanks imo1131, great suggestion.

i don't think there was ever an issue for my father with this. He rode unloaded most of the time, commuting through the snow. I was planning on putting it back on this winter and will look into this further. Thanks for passing it along.

Here is are a of pics of the mounting it had.