Author Topic: lighter clutch operation  (Read 704 times)

Online Billybream

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lighter clutch operation
« on: 02.03. 2016 09:50 »
Getting old and the hands are struggling with arthritis, well the knuckles, so looking to improve the 4 spring.
Is the SRM alloy plate with Top hat needle bearing the way to go, together with the the push rod ball bearing mod. My standard set up is not bad, but a lighter action on both in and out would help me. Liked the look of Brian's mod with std plate welded to plain plate and addition of Top Hat bearing as well.
1960 Super Rocket, owned since 1966, back on the road 2012 after being laid up for 29yrs.

Online cyclobutch

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Re: lighter clutch operation
« Reply #1 on: 02.03. 2016 12:56 »
I recollect some discussion somewhere on hydraulic clutch conversions, can't remember where. Might be worth considering depending on the depths of your pockets. Kind of this sort of thing I suppose:
Various, including ...
'58 Iron Head Flash Bitza

Offline coater87

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Re: lighter clutch operation
« Reply #2 on: 02.03. 2016 13:35 »
 WOW *eek*

 Thats some big money for a chunk of hydraulic hose, a reservoir and a cylinder. I could be wrong, but that seems ridiculous.
Central Wisconsin in the U.S.

Offline bsa-bill

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Re: lighter clutch operation
« Reply #3 on: 02.03. 2016 14:40 »
I could be wrong, but that seems ridiculous.

I have to agree with you, specially as I can operate the clutch on both of my bikes with one finger, one has SRM conversion the other has much the same from Lyford Classics
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Triton Thrasher

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Re: lighter clutch operation
« Reply #4 on: 02.03. 2016 17:48 »
If you want to keep it simple and cheap (I do), you can play around with handlbar levers with shorter distance from fulcrum to cable nipple, or let some pressure off the clutch springs. No guarantees though.

I take it the cable is already oiled and free from tight bends.

Online ellis

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Re: lighter clutch operation
« Reply #5 on: 04.03. 2016 11:44 »
My clutch was quite heavy too until I lubricated the cable, now I only need to use two fingers (together and not apart)  *whistle*

Offline BSA_54A10

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Re: lighter clutch operation
« Reply #6 on: 05.03. 2016 11:28 »
yes the SRM ( or any of the other brands out there ) alloy pressure plate with radial roller thrust bearing and top hat lifter is well worth the money.
OTOH adjusting the cutch according to BSA's directions will lead to a clutch that is way too heavy unless you ride an outfit with an elephant in the chair & a rhino on the back.
Once you have the pressure plate lifitng square.
Put the bike in gear
Put the front wheel against some thing solid like a brick wall.
Adjust the nuts back an equal amount till kicking just starts to slip.
Do all the nuts up 1/2 turn each then take the bike for a test run trying to force a clutch slip accelerating hard in top gear from a slow speed.
If the clutch does not slip either leave it there or back each nut off 1/6 turn and repeat till it does then tighten 1/6 turn.
Pur the cahincase cover back on.
You now have the lighest possible clutch adjustment.

Now you look at the cables and levers as others have suggested,
With nothing more than the Devimead ( yes I am that old ) lifter & bearing  fitted I got my A 65, B 50 & B 40 to a two finger clutch.
I use Tri-Lube dry lubricant on my cables exclusively, it is made for pushbike gear cables ad is very slippery and ofter the transport medium evaporates totally dry so it does not clog up when exposed to dust.
As posted earlier there ar several different ratio clutch handles which will give you either more lift or greater mechanical advantage but to work, all the pivot places ( bars & box ) must be true so you may need to bush both holes.
Bike Beesa

Offline worntorn

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Re: lighter clutch operation
« Reply #7 on: 07.03. 2016 04:05 »
I improved my very stiff Commando clutch fby changing from a standard cable to a Venhills Teflon and Stainless steel cable. Effort to move the lever changed from 24 lbs pull down to 16 pounds pull just with this change. The 24 lb pull was measure with a/spring scale and was with a freshly lubricated standard cable in pace.
With the Venhills Featherlight cables you never need to lube again, in fact they work better without lube. Stainless steel and Teflon is a very slippery combo.
After the cable switch I reset the stack height so that only 7 pounds pull (one finger) is needed now to move the clutch, but that procedure is for diaphram clutches.