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throttle cables

Posted: Wed Apr 20, 2016 6:33 am
by bluesman
Hello all,
I own a naked 79 r100rs. I noticed that the left throttle cable is becoming frayed and I want to replace them. The problem is It now has what I think are "S" style bars. Would the original cables for the RS work with the S bars. Would PN 32 73 1 236 615 listed for r1oo w/ lo european bars be the correct cable for this.

Thank you,

Re: throttle cables

Posted: Wed Apr 20, 2016 6:57 am
by Kurt in S.A.
It really comes down to length. I have cables from an '84 R100RT on my '78 /7 because they were the longest I could get to fit with my barbacks. The part number you quote shows 1027mm in length which I believe is the length of the sheathing...not sure about that. What is the length of your current cables?

From RealOEM, a 1979 R100RS shows as having cables 1108mm long, 32 73 1 236 616.

Kurt in S.A.

Re: throttle cables

Posted: Wed Apr 20, 2016 1:19 pm
by enigmaT120
Ugh. The trouble is measuring them while they're on the bike, as if you remove them to measure them you can't ride the bike. Or you put them back on and ride until you get the new ones, then remove them again to install the new ones.

I know this isn't any help, I'm just sympathizing. Has anybody measured his or her cables on the bike, like maybe running a string or wire along them and marking the ends?

Re: throttle cables

Posted: Wed Apr 20, 2016 1:42 pm
by Kurt in S.A.
Yes, it's a bit of a problem measuring them while installed. I would imagine using a piece of string and gradually putting in place along the route would help. But the issue is to get with 15-20mm which I wouldn't think would be too difficult. See if the current ones measure around 1035mm...maybe them measure 1050mm...or something. I'd take the time to measure before I committed to new cables.

I went with longer cables on my bike because of the barbacks...with the old cables, they were making a pretty sharp turn into the tops of the carbs...wasn't good for throttle action and synching.

Kurt in S.A.

Re: throttle cables

Posted: Thu Apr 21, 2016 11:39 am
by George Ryals
Take a look at this site for cable info.

http://largiader.com/articles/throttles/

AND this one

http://largiader.com/articles/cables/

Re: throttle cables

Posted: Fri Apr 22, 2016 8:41 am
by bluesman
Thanks everyone for insight and info. I guess is my question is are there problems if the cables are longer. The reason I ask is Maxbmw website lists 32 73 1 236 616 for the RS, RT, /7 which is 1108mm but also shows the 615 at 1027mm for the RS and S models. I'm so confused!

Re: throttle cables

Posted: Fri Apr 22, 2016 8:57 am
by Kurt in S.A.
I don't think there would be a problem, as long as the attachments are the same, which I would think they would be. As I said, I have longer cables from a completely different bike on my /7. In my case, longer was better as it gave me more room to route and position my cables.

Kurt in S.A.

Re: throttle cables

Posted: Fri Apr 22, 2016 9:40 am
by bluesman
Thanks Kurt I guess I'll go with the longer ones just to be safe.

Re: throttle cables

Posted: Fri Apr 22, 2016 10:16 am
by Rob
You can go longer, you just can't go shorter.

Make sure routing is smooth, no sharp bends.
Check everything at full lock with the engine idling. Make sure that the revs don't change lock to lock.

Re: throttle cables

Posted: Fri Apr 22, 2016 10:31 am
by Duane Ausherman
We often would use cables that were a bit too long. Just make wider sweeps to use up the cable. We often would remove the stock "cowboy" high bars that were stock and replace with the shorter lower Euro bars. No reason to add the expense of changing cables, so we would reroute them.

The easy place to do this is by routing them on the other side of the steering head/neck. It is prudent to keep the cables attached under the tank in that large black rubber block that holds them steady just above the carbs.