bsa a10 clutch info

[frankenstein]

is my 1960 a10 gold flash a dry clutch....as i am led to believe that until 1959 they where all wet clutch as factory standard....my a10 has the 4 bolt centre and the primary chaincase has two inspection holes one for the primary chain and one for the clutch....also do any of the a10s have a primary chain tensioner...cheers!

[groily]

Hi there,
You've got a 4 spring clutch then, and it's wet! They all are, whether they like it or not, so the chain gets a break (or not, I should say).
Tensioners live with duplex chains on plungers with the bolt-on gearbox where there's no provision for hauling the box back and forth to get the tension right. Retrograde step many might say to have abandoned that design with the swinging arm frame - presumably to make the thing longer and fill the gaps up. Anyway, stuff oil in, it'll like it. That's what the big hole is for, as well as for making sure there's some slack in the chain; the little one is to give you access to the clutch spring screws to adjust their tension when it slips in the middle of the night and the pouring rain.

[frankenstein]

thats superb info...do i need a special tool to (see pic) tighten the clutch springs as when i look through the inspection window the slot for the screw driver does not run accross the whole head nut

[dpaddock]

Take a large flat screwdriver and cut a notch in the blade to fit. Gotta be cheaper than that tool you've shown!

[fido]

Hi there,
You've got a 4 spring clutch then, and it's wet! They all are, whether they like it or not, so the chain gets a break (or not, I should say).

Not sure whether you meant all 4 spring clutches or all A7/A10s. but if you meant the latter then it is not correct. My 1948 A7 has a domed cover with gasket over the clutch to keep the oil out. On swinging arm models the clutch is wet.

[groily]

apologies Fido you're dead right as ever . . . think the advice was good for this one though (hope so anyway)

[RichardL]

Just curious here, is the clutch otherwise sealed against oil incursion, with the dome completing the closure? Or, is it a sort'a damp clutch versus sopping wet? I'm in a virtual no-knowledge zone on this, so, please forgive and educate.

Richard

[groily]

I knew some Ariels had dry (Burman) clutches, with the clutch effectively outboard of the outer chaincase and protected under a chrome dome (had one myself years ago). But hadn't realised BSAs had something similar until Fido put me straight. The chains all need oil though. Guess it's something to do with cork inserts on some clutches not liking the slime. Funnily enough, the majority of other Burmans of my connaissance (being on AMC products) do run in oil; but Ariel, a great marque, was often a bit different. Variety, spice, life!

[frankenstein]

thats great info from everybody....i am now clued up....one last question...do i tighten the primary chain by moving the gearbox...cheers

[dpaddock]

Yes; that's how it's done. Allow at least 1/2-inch chain movement at the tightest position. 3/4-inch is better. Remember to reset the rear chain afterwards.

[frankenstein]

thanks for that info...cheers