Author Topic: A65 - 3 ball clutch operating mechanism  (Read 919 times)

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Bess

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A65 - 3 ball clutch operating mechanism
« on: 21 November, 2017, 10:36:10 »
Hi,
     Has anyone experienced a clicking issue with the 3 ball clutch operating mechanism.

I have one where the balls move with the plates and full back into the depressions with a loud clicking sound. I have tried lubing with oil only and grease only without effect. I guess the plates are worn so I'm thinking of changing the balls from 3/8" to 10mm to see if that works.

Any ideas gratefully welcomed..


Thanks...

Editor

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Re: A65 - 3 ball clutch operating mechanism
« Reply #1 on: 21 November, 2017, 20:01:30 »
There's probably a "they all do that sir" coming here!
When it 'clicks' does the clutch lever suddenly become alot less stiff? If so, I have had this problem from time to time and I put it down to the adjustment in the cable.
My theory is that the distance the bottom end of the cable has to travel is very close, if not slightly less than, the travel on the clutch handlebar lever pivot. I think what happens is if there is too little slack at the handlebar end, the travel exceeds the distance on the ball assembly and the balls actually come out of the cups onto the flat surface i.e tipped over the edge as it were. The reason the lever gets easier is there is no resistance of the climb out of the depressions. They always pop back in so no need to worry. Try adjusting the cable at both ends to get the optimum inner length and see if that makes a difference.
Hope this makes sense.
Chris

Bess

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Re: A65 - 3 ball clutch operating mechanism
« Reply #2 on: 22 November, 2017, 08:31:46 »
Thanks Editor,
                      I have another A65 and A50, they do not suffer from the same problem.

After reading your post I compared the handle bar lever, the pivot distance (end of cable to pivot bolt on the lever) is a few mm longer, the distance between the lever closed and lever fully open is 5mm longer.

So it seems the cable travel is longer on the new lever is causing the problem you describe, different levers will be the cure.

Thanks for you input.....


Editor

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Re: A65 - 3 ball clutch operating mechanism
« Reply #3 on: 22 November, 2017, 18:41:21 »
The 3 ball device was only used from 1970 onwards. Is your other A65 and A50 from the same year i.e. the clutch cable enters the outer cover from the top? The earlier ones clutch cable enters from behind.
One of these days I will do a measurement myself to prove my theory, or find out I'm barking up the wrong tree  :-\
Chris

Bess

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Re: A65 - 3 ball clutch operating mechanism
« Reply #4 on: 22 November, 2017, 19:53:18 »
Hi,
     All three have bikes have been made from parts sourced from around the globe. I particular like the top entry clutch cable so I have used them on all 3 bikes.

I did find this statement on another forum, "The ball mechanism on a Triumph and the lever mechanism on a BSA used to actuate the clutch rod was designed to be used with a clutch lever with a 7/8" fulcrum. Using a clutch lever with a 1 1/8" fulcrum will rotate the ball mechanism, or move the lever, beyond their design limits. The problem for a lot of British bikers is the lever most commonly sold in the after market, and the cheapest, is one with a 1 1/8" fulcrum".

Sort of explains my problem and bears up when I changed the levers around and the problem disappeared.

Best wishes...

Editor

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Re: A65 - 3 ball clutch operating mechanism
« Reply #5 on: 23 November, 2017, 11:31:20 »
There you have it. I use the standard Lucas switch assembly lever on the OIF Thunderbolt and that does click occasionally but is OK most of the time when I leave a reasonable amount of play on the lever adjuster. On the 1970 Royal Star, previous owner, Billy le Bodge put a longer length fulcrum to nipple lever on, probably to make the clutch operation lighter to save his carpal tunnels. Now that one does click alot more!