Handlebar Master cylinder query

[SteveD]

Thanks lads. I suspect the 12mm m/c would allow too much lever travel. The offer for the 12mm was cheap though, so worth the question.

You may want it someday for a single disc application. If it's that cheap, you may want to jump on it anyway.

I can't foresee that, and there are priorities for the hard earned y'know! If it was a 13mm or 14mm I would...

[SteveD]

Grant dismantled his dual front Brembos last week. The '81 R100 front brakes were less than enthusiastic when it came to stopping. The lever would only travel about 1cm and the brakes were very poor with little "feel". The stock 15mm m/c had a little crud in it, but not much. Cleaning added a little improvement in lever travel, but not much.

So we had a good look at the two front calipers. Those wiper seals surprised us.
This is what we saw when we removed the first piston.


We cleaned and replaced the four wiper seals on the two calipers because they were all damaged...


What we should've done at the time was work out if the damage was on the inner or outer aspect of the seal. Unfortunately we just got on with the task, but zooming on the picture above makes me think it's the inner or lower edge that gets damaged.

Travel is now much improved. The road test report shouldn't be too far away.