bsa zb31

[grommit]

I have a trails style bsa with high level pipe.It was sold to me as a gold star but has iron engine (head and block) did goldstars have this ?The case is stamped ZB31

[DoctorKno]

Hey Grommit, I have a ZB31 and as far as I can tell they were made between 49 and 54. The goldstar has a newer engine.
Mine's a little chopped but still has the feel of the original bike
Cheers

[BikerBSA]

The ZB31 was made from 1949 to 1952 and to be a Gold Star the engine would have had to be ZB32, and the motors alloy, however they did make an alloy B31 motor in 1950.
All the frames for these ZB31 models would have been either rigid back end or plunger, also refered to as a sprung frame. ....BikerBSA