I am putting a 1971 BSA B25ss back together (bought in boxes, note to self, never again!) I have new needle bearings, seals etc but cannot find a spacer tube, isa part number 83-1969. Any help in sourcing one would be appreciated, alternatively anyone have any idea how I can get standard measurements to get one machined (other than measuring it myself).
Have you tried Kidderminster Motorcycles or Vale Onslows? If no luck there, try Owens Motorcycles because they have a shed full of used BSA spares - I visited once to get a new B25/B50 frame and swinging arm and, at the time, was spoilt for choice. In desperation, I have also turned to buying BSA spares from the US. Kempf's British Parts seem to have them in stock:
http://www.klempfsbritishparts.com/TUBE--SPACER--SARM--OIF-SGL-0
Thank you, unfortunately Kemp's don't have one in stock. Owens is looking so may have a solution there, thank again for the pointer.