Another cable issue

Discuss all things 1970 & later Airheads right here.
Post Reply
User avatar
jagarra
Posts: 896
Joined: Mon Dec 26, 2011 12:42 pm
Location: Reno, Nevada

Another cable issue

Post by jagarra »

I finally got around to replacing the brake cable going to my under tank M/C. The new cable was strung through the eyelet under that top clamp, through the hole in the front of the frame and positioned to go into the M/C. I hooked up the lever end first and went to hook the cable to the M/C, won't reach, cable too short. Both adjusters turned all the way in, still too short. Took it apart on the lever end, removed the barrel from the lever and tried it, didn't slide on all the way. Seems when they crimped the ferrule on the end it has a hex crimp and the hole in the barrel was too small. Drilled out both barrels and tried it again. Still not enough slack to hook it up on the M/C end, what the crap!! :shock: Now I pulled the cable again and checked it against the original cable, looks like the housing was made just a bit too long and is eating up my slack, I first got a measurement of 10MM too long. Called the dealer, they are going to order another and call me next week.
Determined to make it fit I looked for a way to get more slack. I had an extra adjuster from my old M/C, so I removed the lock nut, that was 5mm worth, measured the thickness of the housing, I could machine a few more MM to give me more, managed to gain another 3mm from that effort. Put the whole thing together again and it I still couldn't hook up the barrel on the M/C end. :cry: I went to my spare stash and found a new after market cable, it looked about the same, inner cable longer and I put the unmodified adjusted back on, and manage to hook it up, but it was a real bear to get the damn barrel hooked up on the M/C.
Cable in question was BMW part # 32 73 1234 400 for a pre 9/75 R90, it had a date code of 11/09/2012 on it.
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
Rob
Posts: 3105
Joined: Thu Feb 13, 2014 2:05 am

Re: Another cable issue

Post by Rob »

I once had trouble finding OEM throttle cables (no splitter) that were long enough (internally). After two pair, I gave up and found a shop that sold cable and nipples, and made my own.
For that I had to learn to solder with silver solder and an open flame.
Rob V
Kurt in S.A.
Posts: 1715
Joined: Tue Aug 03, 2010 12:08 pm

Re: Another cable issue

Post by Kurt in S.A. »

Don't go through the eyelet in the top clamp??? It seems you have the right cable, 653mm long. How does it measure up to your old one? Unless you're a purist, it's just about getting it to the M/C with no sharp turns or kinks and allows operation when the bars are turned stop to stop.

Kurt in S.A.
User avatar
jagarra
Posts: 896
Joined: Mon Dec 26, 2011 12:42 pm
Location: Reno, Nevada

Re: Another cable issue

Post by jagarra »

I followed the same path as the cable I removed. From the looks of it, it was an original BMW unit. There is a nice smooth path, and yes, I compared them and the housing is longer on the new brake cable. I first thought it was 10mm, finally I clamped the boss at the end of both cables in a vise side by side and stretched them out, new one is still longer on housing. There are still differences. Biggest issue is compressing the piston on the M/C enough to allow enough slack to install the barrel. I tried vice grips, clamps, finally ended up using a big pair of slip joints pliers and fished it with the other hand. That was on the after market cable.
This whole process has me wondering what's up with the OEM cable, when I was changing M/C a lot when I was working on my calipers, I unhooked the original cable quite easily.
I really like the quality of the OEM cables, will have to see what dealer comes up with on the replacement, hopefully it will be a different date code.
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
Seth
Posts: 279
Joined: Thu Aug 12, 2010 4:45 pm

Re: Another cable issue

Post by Seth »

Assuming the cable has enough length to release the master, I've installed new cables by opening the bleeder to allow the lever on the master to move all the way in, making it easier to install the cable. Of course, you have to make sure that it allows the piston to return back far enough to open the 2 holes within the master.
Post Reply