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British Bikes / BSA B31 Rigid (1949)
« on: August 24, 2026, 05:49:39 PM »
I have a couple of questions about the clutch on a 1949 BSA B#! rigid. It's a 6 spring clutch.
The clutch basket that came on the bike is worn beyond reasonable repair. I manage to fine a NOS one on evilbay, but when I started reassembly I notice a couple of differences.
1. The band around the clutch basket that came with the bike is 1 inch wide.
The "new" one is 1 1/4 inch.
It seems to clear the outer cover so no rubbing or dragging is noticed.
Is that difference in width going to be a problem?
2. My mechanics manual states that the clutch should have 5 fiber plates, although some folks went with 4 back in the day.
My bike came with 3
Should I add one or two or is it ok with the 3?
3. Last question. When I torque down the mainshaft clutch nut (no where near the 60 ft-lbs, but tight) the transmission seems to bind up It turns, but is tight.
I look forward to your advice.
Thanks.
The clutch basket that came on the bike is worn beyond reasonable repair. I manage to fine a NOS one on evilbay, but when I started reassembly I notice a couple of differences.
1. The band around the clutch basket that came with the bike is 1 inch wide.
The "new" one is 1 1/4 inch.
It seems to clear the outer cover so no rubbing or dragging is noticed.
Is that difference in width going to be a problem?
2. My mechanics manual states that the clutch should have 5 fiber plates, although some folks went with 4 back in the day.
My bike came with 3
Should I add one or two or is it ok with the 3?
3. Last question. When I torque down the mainshaft clutch nut (no where near the 60 ft-lbs, but tight) the transmission seems to bind up It turns, but is tight.
I look forward to your advice.
Thanks.