BSA Owners' Club Forum

The BSA Workshop => Pre War => Topic started by: copp1354 on 23 August, 2017, 09:33:35

Title: jb21
Post by: copp1354 on 23 August, 2017, 09:33:35
hi I am new on bsa I got a jb20 engine jb21 model I would like to know how many they where produced ? and I would like to know where I could findthe front and rear fenders if possible?

thanks in advance
claudio
Title: Re: jb21
Post by: JulianS on 23 August, 2017, 11:51:29
Engine with JB20 engine number is a B20 250cc side valve model from 1938 season. It would have been fitted into a frame starting JB20.

JB21 is also an engine number but for a B21 250cc ohv sports. It would also have been fitted into a JB20 frame.

The JB20 frames were fitted with B20 250 side valve engine, B21 250cc OHV sports engines, B22 250cc Empire Star engines and B23 350cc  side valve engines.

Expect a relatively low production number of around 1200 each for the B20, B21 and B23.
Title: Re: jb21
Post by: copp1354 on 23 August, 2017, 14:20:58
yes mine is a jb20 sport engine and frame are correct