The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: mayes on 18.03. 2013 22:48
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it has been very long time since i had an A10 I have just brought a distressed 1955 golden flash on some work getting it running I found a oil leak from the primary rear chain case coming from the rear having striped down there is no shock assober fitted is this right ?.also there seems a cap between the gear shaft and clutch any help would be welcome Thanks John old
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I reckon it should have a cush drive, i suggest you look around for a parts book as that will help you work out whats missing etc, but draganfly has a good site with diagrams etc in the meantime. Ref the gap any chance of a pic? These bikes often leak where the gearbox shaft enters the chain case there is a diamond shaped sliding plate affair which does not do good job of keeping oil in the case!
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Hi John,
Concerning the cush drive, possible you have a conversion to the cush drive type clutch.
This website may be of some help to determine what you've got.
It's got all the parts in pictures, so its easy to compare.
http://www.degroot-bsa.nl/index.php
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To ensure there is no confusion, the cush drive I was referring to in my earlier post is the one fitted (or that should be fitted - on a std bike) on the drive side of the crankshaft.
Some clutches may have "shock absorbers" or cush drives as part of their design, if a clutch has a shock absorber as part of it's design I do not know if that means the cush drive on the crank is no longer required. A parts book, possibly from a different model would help here.
Fitting a non std clutch is fairly common on A10's, the most popular conversion seems to be to fit a 4 spring "Triumph" clutch which was std on later bikes, usually fitted in place of the much maligned "6 spring" clutch (which I have in my bike by the way).
Pics will help identify what you have. Both older and newer original parts from other models will could have been fitted, some bikes had duplex primary chains, some had alternators etc.
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It is often said (could be myth) that a clutch with cush (rubber inserts ) centre should not be used with a bike with crankshaft cush as they fight each other *fight*, on one hand there is some logic to it on the other hand difficult to prove.
I don't know for sure so I'm open to suggestion - was the rubber cush centre intended for bikes with an alternator as maybe they don't have the crank cush
I'm thinking out of the envelope here (see more cool speak)
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I'm no expert on the clutches, other than I'm not a fan of the early S/A 6 spring, but do like the Plunger 6Sp., and am fairly sure that I've seen reference to the Alternator models that suggest as you(Bill)do that they need to run cush in the clutch- out of desperation I fairly sure I actually grafted a clutch from a M20 onto my Road Rocket back in the '70's when bits were hard to find- from memory worked a treat!
Happy duelin' Bill- maybe try it with Banjo.? ;~)
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bsa-bill. I had a gold flash that had the cush drive on the crankshaft and also I fitted a 4 spring Triumph clutch with the rubber inserts I had that bike for 16 years with that arragement and no problems.
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John
I think that someone has put far too much oil in you bike causing it to splash out behind the clutch, check your levels correctly. Please let me know how you get on. Whilst you have it stripped you may as well fit new clutch plates and roller bearings if required.
Regards Colin
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Triumph clutch with the rubber inserts I had that bike for 16 years with that arragement and no problems.
Hi Bob - yes I can't see too much of a problem (hence the myth bit) but it one of those thing you hear said quite often
Wonder what Triumph used them on, I have one but there's a bit off play on the centre so I replaced it with an open centre one, I bought the whole clutch off the Evil place so it possibly came off a Triumph.
Hoped someone might know where they were originally fitted
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Bill,
The rubber cush clutches were fitted to alternator models, both BSA & Triumph.
Trev.
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the problem was to much oil i.e 3 times to much there seem's that some early data stated 7/8 of a pint wrong thanks all
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The rubber cush clutches were fitted to alternator models, both BSA & Triumph.
Cheers Trev I wondered if that was the case or only case