Hi. Does anyone know if the bearing and seal sizes ie mains and clutch, gear selecter etc, are common for all the 5 speed sherpa crank cases throughout the years.

Somewhere around 1973 the gearbox mainshaft diameter changed where it sits in the clutch side bearing, therefore so too did the bearing size. Can't be any more specific than that though, sorry, no idea if there is a specific model number this occured from.

Crank bearings and seals are all the same size

Clutch hubs and baskets differ, as does the spacer the hub sits up against

Later gear selectors forks are thicker than early ones and won't fit early gears

Bultaco UK is your obvious source for this info

You may have to search a bit but most bearing sizes are there:

(Be advised: I don't know if some Bultaco bearings have more play than standard, for instance C3,)

http://www.francetri.../en/21-bearings

Seals:

http://www.francetri...en/16-oil-seals

No worry's mate

Edited August 22, 201313 yr by guys

Many thanks, I'll give them a look. I am aware of the fact that some of the bearings need to be C3 spec, and also of the need for viton seals for the crank.