Hi, I have a ZB31, rigid, 1949. Frame and engine numbers both begin ZB31 but the last four digits on both frame and engine are different. Can anyone tell me if this is as the bikes left the factory? or would those last four digits on the frame and engine have matched at the time? I've looked and looked on google but could not find that specific information anywhere.. I found information on what the numbers should run from and to, but not as to whether they would have been same on frame and engine. many thanks
The numbers are very unlikely to have been the same in 1949.
The 1949 ZB31 frames were used by the B31 the B33 and the B32 and B34 non Gold Star competition models.
thanks Julian :-)