The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: broom34 on 18.07. 2009 19:08
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Hi
I'm just in the process of rebuilding an A10 Gold Flash Plunger 1957, and I want to replace the old clutch with a new belt driven one , now my question is, are there any conversions for the A10 plunger , or would a Triumph conversion kit fit OK .
Anyone out there that can advise me please
Richard
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G'day Richard, I don't know for sure but try Lytedrive in Melbourne Oz, John Scarri. [email protected] . I am about to order one for A10 s/a $1000 AU diaphram clutch with sealed bearing can run wet or dry.
Cheers
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hi mate i had mine done and its a sweet ride now go it from srm
heres a pic
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Hi Muskrat & Rocketman
Thanks for your replys I will be sending e-mails off to your suggested sites for more information *smiley4*
Richard
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As one with no experience of different clutches on given bikes, I can't help but wonder what difference I would note between my 6-spring s/a clutch (adjusted quite well, I believe) and other available types. Somehow, I am confused why a $1000 AU (491 GBP) clutch could be so much better than a 260 GBP 4-spring clutch from SRM or, even, my very inexpensive 6-spring, which seems to do everything I want.
As the expression goes here, can somebody "talk me down?"
Richard L.
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As one with no experience of different clutches on given bikes, I can't help but wonder what difference I would note between my 6-spring s/a clutch (adjusted quite well, I believe) and other available types. Somehow, I am confused why a $1000 AU (491 GBP) clutch could be so much better than a 260 GBP 4-spring clutch from SRM or, even, my very inexpensive 6-spring, which seems to do everything I want.
As the expression goes here, can somebody "talk me down?"
Richard L.
Richard,
The reason Ive been using a belt drive on my last 2 bikes for the last 10 years is ,
a) both bikes needed new clutches,
b)once set up you never have to adjust them as the belt doesnt stretch.
c) I run them dry so that eiminates a potential oil leak .
d) runs much quieter than standard with no clatter from the l/h side.
e) The kits I use (Tony Hayward ). use friction material that allows you to back off the springs .In conjunction with a nylon lined clutch cable you get 2 finger operation which is very pleasant and impresses other bike owners no end.
f) Apparently ,(and Im not sure about this one),a belt absorbs less power than a chain .
Mike
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thats also why harley davidsons have a belt drive rear wheel
it absorbs a lot more than a chain and chains stretch a lot more
and a lot ove harley custom bikes have belt primery drives in *smile*
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Hit the nail on the head Mike. It's down to preference as to which one to use. I prefer the diaphram with less parts. One thing though Richard, I think the mainshaft is different on the semi unit to the s/a. It's been a long time (8 years, 15000 miles)) since I looked at my std 6 spring clutch in my '51 plunger !! See even Richard L is right.
Cheers
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It may not be easy getting a different clutch for a plunger A7/A10 as there is not much room in there.
Trev.
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Guys,
I have seen other belt drive clutches for our bikes, does this one require "ventilation" to run correctly? One conversion I have seen had odd shapes and what-not cut into the primary case. I asked the owner why in the world he would do that (its not like it was a full-on chopper), and he told me you must do this with his belt drive or everything will over heat big time.
Lee
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mine was done by srm with a normal outer primery case
with no cut outs and i have had no problems
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No vents in mine either.
Heres a thought though.Can you fit a belt drive to rigid or plunger semi-unit engine?how would you tension it?
MN
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thats a good point i had a triumph unit with a belt drive on it
and it was on before i got the bike mybe belt drives dont need to be ajusted
like a chain does like i said a chain streches a lot more than a belt does
so if the belt is the right tension when you put it on it wont need ajustment
so it could be used on a unit engine bsa
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Ref the ventilation point with belt drive primary drives ......I ran a Goldie with a Bob Newby belt drive and left off the sliding oil seal device normally fitted behind the clutch which provides ventilation. Ran with no probems whatsoever and still problem free after 3 years.