I got the gearbox out of the frame today for the sealed bearing job, but my attention was diverted to the clutch. The clutch sleeve is very tight, requiring a soft-faced hammer to move it in or out of the 22 rollers in the chainwheel race. Once it is in, it doesn't want to spin freely on clean, greased rollers. What is happening?
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Hi Tom..Now that is unusual..the reverse is normally the case!.You are going to have to take some measurements....First check the rollers...they should be 1/4"x1/4"..(.250") and should be bang on that size if new, perhaps a cpuple of thou under if used.
The bearing race in the sprocket should measure 2.0283"-2.0288" when new...
The bearing track on the clutch sleeve should measure 1.5273"-1.5278" when new..You will need to use micrometers for all measurements for an accurate result...Ian
Thanks, Ian, I'll get those measurements and report back.
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Hey, Ian, about half the rollers are slightly oversize at .251 inch diameter. A few are undersized at .249. Do you think those oversized ones are jamming the sleeve? I didn't get measurements on the sleeve and inner track. Maybe I should buy a set of new rollers anyway.
Hi Tom...That's quite likely as the tolerances on the clutch bearing track and clutch sleeve are only half a thou (.0005") and with .001" oversize rollers they will be .002" too large across the overall assembly diameter. I would go with new rollers and see if that improves things...Ian
Thanks again, Ian. New rollers it will be.
Hi Trevor..Not for the BSA B & M Series big ends, which have 1/4"x5/16" rollers not 1/4"x1/4"...However, they are worth hanging onto for a clutch that does have worn bearing tracks!...Ian