Hi , Is there a selection of rear sprocket sizes available for 1963 A65 Star, 4 bolt fitting type
I'm only aware of 4206331 (42T) and 68-6034 (43T)
The usual changes to drive ratio are on the engine sprocket or the gearbox sprocket.
I have a 42T rear sprocket but feel it could be geared up I'll have to check the engine and gearbox ones then see what's available
I raised the gearing on my A65, made it much nicer to ride and moved the vibration out of the normal range. I fitted the biggest gearbox sprocket I could get, I think its 22T, this is the easiest way to up the gearing. Mine was a late model and the case was cut behind the clutch so the 22T would fit. I don't know if this was standard on all A65s, someone will know or call SRM as they sell the 22T sprocket.