throttle cable length

[jwetering]

so my throttle cable became frayed inside the bowden box causing a stuck open throttle in traffic.



I have it out now (way more fiddly than it should have been IMO) and am just fixing to buy a new cable......

Here's the rub: BMW lists two lengths - one for high bars and one for low bars. 600mm and 570 mm respectively.

My bike came with low bars and the frayed cable is the shorter length, but I've installed bar risers so I think I should order the longer cable for the high bar.

What do you guys think?

[Bengt Phorqs]

The cable should have a part number marked on it. That is the part to order. You know the ones on it work so just replace with the same p/n.

[jwetering]

Originally Posted by Bengt Phorqs

The cable should have a part number marked on it. That is the part to order. You know the ones on it work so just replace with the same p/n.

Well yeah....except it frayed and failed - which may be because it is too short now that I've installed bar risers. Binding in the box is my concern.

[Bengt Phorqs]

To clarify, the cable sheath should have the part number on it. I changed several throttle cables on oilheads with the Bowden box over the years and always purchased the cable with sheath based upon the P/N on the cable sheath. Perhaps I have misunderstood your situation?

[ckcarr]

I believe jwetering knows the part number is there.

My bike originally came with the low bars and now has Randy's Barbacks on it. I doubt anyone here has changed the cable because of those. Perhaps you could pm him and ask what he recommends.

How many years before it frayed?
How much do the parts cost?

I'd probably just get the proper part number also. You are assuming a cause & effect, which may not be true.

[brentw1]

the longer ones would be what I would do,
you can alwasy lenthen the routing, hard to go the other way.
I have risers as well and they just fit it would be nice to have a couple of inches spare.

[lkchris]

Just know that the cables available today assume installation of new parts at the handgrip as specified in a service bulletin.

If you still have a 90-degree bend in plastic attached at the handgrip, that needs to be removed and replaced with new parts that allow the new cable--with a 90-degree bend inside a metal tube--to be fitted.

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[jwetering]

Originally Posted by ckcarr

I believe jwetering knows the part number is there.

My bike originally came with the low bars and now has Randy's Barbacks on it. I doubt anyone here has changed the cable because of those. Perhaps you could pm him and ask what he recommends.

How many years before it frayed?
How much do the parts cost?

I'd probably just get the proper part number also. You are assuming a cause & effect, which may not be true.

Hmm - I think you might be.

My bike was delivered with low bars, therefore it had a low bar cable installed. This is the cable that failed.

Then I installed a bar riser kit - effectively making the bike a high bar model. After installing the risers - my cable failed. It is possible that the failure was related to the fact that I was using a low bar cable on a high bar bike. Note I said possible not probable.

Anyway - now that I am replacing the cable anyway - the question was whether I should install the same low bar cable that was in the bike, or change to the high bar cable........since I now have high bars.

If I do choose to install the cable for the high bars - that means the number marked on the sheath would be the wrong number...that make sense now ?

As it happens - the part number on the sheath is no longer active - it doesn't even show up in my dealer's database anywhere. It's been supeceded and the new cable requires a new fitting at the handgrip . In Canada the while shebang was going to cost me $150.

The GOOD news is that my dealer had a new old stock high bar version of my cable in inventory ! Only $40 and I'm in the process of installing it now.

[jwetering]

Originally Posted by brentw1

the longer ones would be what I would do,
you can alwasy lenthen the routing, hard to go the other way.
I have risers as well and they just fit it would be nice to have a couple of inches spare.

Thanks Brent - just the advice I was looking for and exactly what I was thinking anyway. You da man again.

[jwetering]

Originally Posted by lkchris

Just know that the cables available today assume installation of new parts at the handgrip as specified in a service bulletin.

If you still have a 90-degree bend in plastic attached at the handgrip, that needs to be removed and replaced with new parts that allow the new cable--with a 90-degree bend inside a metal tube--to be fitted.

Yes - I discovered this as well. In the end I went with an old stye cable which was in stock at my dealer because:

a) it was there instead of 3 days away
b) it was significantly lower cost solution
c) my cable frayed in the bowden box not at the hand grip so the 90 degree bend isn't worrying me particularly.

I should be good for another 40,000 kilometres with this fix.

[jwetering]

WOW!

What a difference a throttle cable makes.

I guess this thing has been binding since I've owned it because it feels like a new bike. I bought it almost exactly a year ago and have put about 10,000 kilometres on it since then.

I've always felt it was more sluggish than it ought to have been, and the erratic idle bugged me as well.

That all seems to be solved now. The bike is snappy as hell and idles evenly. Looking forward to a good summer of riding !

[brentw1]

just check the throttle bodies are synced and close and open at the same time as you crack open the
throttles off of the stops, and there is a enough slack to let them firmly rest on the stops and not tick.

[jwetering]

Originally Posted by brentw1

just check the throttle bodies are synced and close and open at the same time as you crack open the
throttles off of the stops, and there is a enough slack to let them firmly rest on the stops and not tick.

Yep. Got em dialed in just right. Exactly as you describe. I cinched up the fitting at the TB until they *just* began to tug on the cable then backed them off a quarter turn each.

Nailed it first try, the bike idles more evenly than I've ever had it.

Thanks Brent

[wiggledbits]

Originally Posted by brentw1

and there is a enough slack to let them firmly rest on the stops and not tick.

Wondering what you mean by tick?

[jwetering]

Originally Posted by wiggledbits

Wondering what you mean by tick?

If the cables are too tight the throttle plates will flutter and make a ticking noise.

In fact my bike had been doing just that for a long time when the frayed cable was binding in the sheath. It annoyed the hell out of me but I didn't put 2 and 2 together until the throttle stuck open the other day.

[wswartzwel]

Throttle plates will also flutter and make ticking noise, when the throttle body bushings are worn, which is pretty common on high mileage bikes.

[brentw1]

ive done lots of these and often the cables are just a bit to tight if they are ajusted
so they just rest on the stop not running ,
when the bike runs the butterfly will cause them to move off of the idle stop and make
a ticking noise on the stop,
so I always check them warm at idle, keeping them firmly on the stops usually means the
cable will have some slack.
then they need to pull off of the stop in a syncronized way, which I check with a balance meter

can also be worn shafts and bushes.

[wiggledbits]

Originally Posted by wswartzwel

Throttle plates will also flutter and make ticking noise, when the throttle body bushings are worn, which is pretty common on high mileage bikes.

this I have known about and did the Cotta kit fix on the GS with 80k on the clock. Only the right side needed it. I have a small tick on the right of the 11S and have it down for maintenance so checking cables is added to the list. it feels a bit tight cold.