BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: nablats on 01 Jun, 2026, 20:36

Title: 1967 A65 clutch backlash?
Post by: nablats on 01 Jun, 2026, 20:36
(Bike freshly back on the road after 2 years fettling)
    I have fitted a belt drive clutch plus 7 plate conversion. The gearchange is good, clutch not too heavy, neutral easy to find at rest, basically happy, but there does seem to be excessive backlash in the drivetrain when rolling on/off throttle in the lower gears.
   Is this normal?, cannot remember if this was less noticeable with the original chain primary, which has an adjuster to tension the chain.
(Maybe I am too used to my modern Enfield with a cush drive)
Title: Re: 1967 A65 clutch backlash?
Post by: DAVE BRADY on 01 Jun, 2026, 21:55
Hi,

What belt drive kit have you fitted and does it use the original clutch centre that has a cush drive in it?

Dave.
Title: Re: 1967 A65 clutch backlash?
Post by: nablats on 07 Jun, 2026, 18:37
I have a new clutch centre, (I hope it has the rubbers inside) Also new SRM pressure plate.
(my previous reply didn`t load)
Title: Re: 1967 A65 clutch backlash?
Post by: DAVE BRADY on 08 Jun, 2026, 08:18
Hi,

The new centre will have rubbers in other wise there would be a lot of movement in it and it would be very noisy in use.
Are you feeling the back lash in the gear box or overall at the back wheel?
Assuming the new centre is nice and tight on the gear box shaft and there was not wear on splines it could be just he wear in the gear box but add to that a slightly loose gearbox sprocket on slightly worn splines and some wear in the spline in the QD hub.  All these small amounts add up. Also a slack chain will to this.

Dave.
Title: Re: 1967 A65 clutch backlash?
Post by: nablats on 14 Jun, 2026, 21:53
 Thanks Dave, you probably nailed it with the bits of wear adding up. I  will keep a keen eye on chain tension.