Clutch Cable Failures?

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Tornado

Tornado

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My bike is now on its third clutch cable in five seasons. Two have failed just after the handle bar end barrel, with the cable fracturing a few mm after leaving barrel. First failure was on a new Venhill cable. I repaired with the barrel off an older cable I took off the HiRider setup. That older barrel had a nylon/teflon sleeve around it to help it swivel in the lever assembly. When I got my bike back from having loads of work done over past three months, the shop had fitted a new cable and from looking at the removed parts box, the Venhill cable I'd repaired had also broken a few mm away from the barrel I'd fitted. New cable is no Venhill as far as I can tell. No nylon sleeve on barrel.

Should I be looking into why this is happening? Some resistence to barrel swivel leading to fatigue?
 
Interested. I recently replaced mine because it had frayed in the same spot.
 
My original clutch lever tends to flop vertically a fair amount, sloppy in the mounting flanges. Perhaps this contributes to cable fatigue. Is it worth trying to shim the lever in the mount to reduce flop?
 
Make sure the barrel in the clutch lever is lubricated. I used to continually break the one on my Triumph until I lubricated it. Also make sure you have some free play at the clutch when you pull it in, I try to give myself at 1/16"
 
You could check the clutch operating lever inside trans is aligned properly. It would create a harder pull on hand lever thus wearing out cables quicker.
 
I went through many clutch cable in my younger days breaking at the lever end then I started to put a dab of grease at the end of the cable and haven't broken one since, the cable rubs on the adjuster when being used so every maintenance service the cable get a dab of fresh grease, my last cable has been on for over 20 years now, in fact can't remember when the last time I replaced it, its been so long, I even put a dab of grease where it enters the gear box cover, but I have never broke a cable there.

Ashley
 
Venhill cables (mentioned by Tornado) for solid (cast) levers generally have a nipple inside a nylon sleeve...

www.venhill.co.uk

N10 NYLON NIPPLE SLEEVE 10mm (3/8") O.D

The sleeve fits over a 6mm diameter barrel nipple giving a new overall diameter of 3/8in (Nominally 10mm). The sleeve is 9mm wide. Typically fitting over a BN610.
www.venhill.co.uk www.venhill.co.uk

...as the nipple rotates within the sleeve therefore shouldn't require much if any, lubrication unlike nipples for folded sheet metal levers.
 
drp said:
Make sure the barrel in the clutch lever is lubricated. I used to continually break the one on my Triumph until I lubricated it. Also make sure you have some free play at the clutch when you pull it in, I try to give myself at 1/16"
Click to expand...
Barrels were well greased up until the two breakages, one with sleeve (Venhill with older sleeved barrel), one without (original Venhill barrel).
 
L.A.B. said:
Venhill cables (mentioned by Tornado) for solid (cast) levers generally have a nipple inside a nylon sleeve...

www.venhill.co.uk

N10 NYLON NIPPLE SLEEVE 10mm (3/8") O.D

The sleeve fits over a 6mm diameter barrel nipple giving a new overall diameter of 3/8in (Nominally 10mm). The sleeve is 9mm wide. Typically fitting over a BN610.
www.venhill.co.uk www.venhill.co.uk

...as the nipple rotates within the sleeve therefore shouldn't require much if any, lubrication unlike nipples for folded sheet metal levers.
Click to expand...
The Venhill I purchased previously did not come with a sleeve and nipple barrel might have been too big for my older hirider cable sleeve.

Is it possible the lever hole for nipple has worn out of round and contributing to failures?
 
Grease is the word.
Molybdenum disulfide to be exact. Or: "moly grease".

I see so many people who view oil & grease as "filth", and are reluctant to use enough of it, if any.
The pivot bolt. EVERYTHING that moves.
 
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Tornado said:
The Venhill I purchased previously did not come with a sleeve and nipple barrel might have been too big for my older hirider cable sleeve.

Is it possible the lever hole for nipple has worn out of round and contributing to failures?
Click to expand...
Yes, I would check for play and also the "tangs" of the lever that surround the cable for burrs/rubbing.
 
My first question would be ............... How hard of a pull does it take to pull the clutch lever in . Years ago on my first Norton i went through lots of cables , broken at both ends . I would have cramps in my hand after a days riding . The dealer at the time repaired broken cables which usually didn't last too long due to his soldering techniques .. On my 1975 i added to the clutch pack , carefully routed the cable which i lube every month with a spray of silicone lube and now have a easy 2 finger pull . Current cable ( A N 06-2813 ) is over 10 years old
 
Before the advent of the sleeved nipple by Venhill and others, tinned brass was used as nipple material, this was ok till the tin layer wore off then the brass nipple against the alloy lever caused the nipple to grab and eventually break.
The cables available now with the nylon sleeve are better but their nipple length is too short, it doesn't have full depth engagement with the clutch lever. This leads to the nipple tilting in the lever and jamming etc. I custom make longer steel nipples and it's nylon sleeve (using graphite loaded nylon) I wish venhills would make a cable like this, then again they wouldn't sell as many....
 
Probably made worse by a worn clutch lever, increasing the up and down play.
 
dobba99 said:
Before the advent of the sleeved nipple by Venhill and others, tinned brass was used as nipple material, this was ok till the tin layer wore off then the brass nipple against the alloy lever caused the nipple to grab and eventually break.
The cables available now with the nylon sleeve are better but their nipple length is too short, it doesn't have full depth engagement with the clutch lever. This leads to the nipple tilting in the lever and jamming etc. I custom make longer steel nipples and it's nylon sleeve (using graphite loaded nylon) I wish venhills would make a cable like this, then again they wouldn't sell as many....
Click to expand...
And yes, I have asked but it was rejected by Venhill. Maybe they like owners breaking cables.
 
I echo Ron's comment - just about every bike I have worked on has responded positively to an additional steel plate in the clutch. An easy check is to put a straight edge across the assembled clutch basket. Measure the difference between two points on the diaphragm spring: 1) next to the retaining circlip, and 2) next to the center hub. The measurement next to the hub should be 0.050"-0.070" less than the measurement next to the retainer, giving the diaphragm a slight convex shape when fully engaged.

This puts the diaphragm spring in the sweet spot, and a super easy clutch pull.

Hope this helps.
 
Tornado said:
My original clutch lever tends to flop vertically a fair amount, sloppy in the mounting flanges. Perhaps this contributes to cable fatigue. Is it worth trying to shim the lever in the mount to reduce flop?
Click to expand...
Mine flops a bit as well, and sometimes buzzes under vibration. I've not had problems with cables.
 
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