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Disc brake cable too short?

44817

New member
I am using /5 lever perches with an under tank master cylinder on my /7. So I bought the front brake cable for an early R90/6 that used this setup. The part number ends with "400". In fact, I've bought two of them. Its installed correctly in the brake lever. The only way I can get it to be close to the right length is to take the adjuster nut off, and even then, the correct clearance isnt maintained where the tool slips over the master cylinder piston. Has anyone ran into this problem? According to the parts book, everything is the same with regards to adjuster, the rod that goes from the master cylinder piston to the master cylinder lever, etc.
 
Yes. I had same problem when I replaced what i believe is the original brake cable last year. I have a '74 R90 with the /5 levers and euro bars.

Should be no adjustment at the handlebar, right? Cable sleeve slides in. No threads like there is on the master cylinder. Are you sure the barrel in the handlebar lever isn't backwards? If it is, it will take up some slack that you need.

With the handlebar end confirmed ok, I still had the same problem you are describing. I had to remove the adjustment nut at the master cylinder end and screw the cable sleeve all the way in. Then, as you describe, it was still just slightly too short. It looked like the metal end on the new cable was larger in diameter than the original and the barrel didn't slide all the way to the end. I ended enlarging the slot in the barrel at the master cylinder end with a dremel tool. This did the trick, adding just enough slack that the adjustment tool fit nicely.

I think the new cables are different.

I'd be interested in hearing if you find a different solution.

Barron
 
For me, on my /6 when I put on shorter bars, the brake adjustment totally went away as described. First, I ground a small bit off of the "plunger rod" that pushes against the master cylinder piston. I really didn't like that at all. Called the guys at:

http://www.benchmarkworks.com/

They took the time to help me figure out that the cable I had was wrong to go with the bars and put me together with a correct cable. Yes, the grinding off a bit on the rod got me "fixed" but it was poor engineering. That little piece went away as I installed the cables........God bless.......Dennis
 
I have an 857 as well, and regardless if it is 1cm longer, the amount of inner cable that sticks out from the outer is the same as a 400 cable. It is also a larger cable, 7mm, vs 6mm for the /5 style levers. So it doesn't fit into the lever barrel correctly.

Dennisdarrow: I'm curious about why putting lower bars on affected your brake adjustment? I did put lower bars on at the same time, but the 400 cable supposedly fits the R90S. Did BenchMark Works steer you toward a different stock cable, or did they make you a custom one?

Thanks!
 
Yea, that's the problem. The cables for the high bars have a longer sleeve. But, the amount of cable sticking out of the sleeve is the same (and it's not enough).

Barron
 
Dennisdarrow: I'm curious about why putting lower bars on affected your brake adjustment? I did put lower bars on at the same time, but the 400 cable supposedly fits the R90S. Did BenchMark Works steer you toward a different stock cable, or did they make you a custom one?

Thanks!

I got the bars and new cables as a "kit" from one of those "good deal" suppliers. My old bars were stock and when I changed them to more of a flat shorter type on the "S" type bikes the older cables had way to much flop around to put up with. So, the new/replacement brake cable must have been just a bit to short or whatever. I called my typical supplier, BenchMark Works, and Rich, I believe, guided me through the measuring of what I now had, both the bars and the cable, then fixed me up with the correct cable. Once I did that, I had the ability to adjust the brake down on the master cylinder like I should have been able to do originally................God bless.......Dennis
 
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