BSA Goldstar ZB32 Competition

At the 1948 Motorcycle Show, BSA announced their new ZB32 Goldstar, special versions of which were offered in various compression ratios and states of tune, port sizes and cam lift for the various sporting needs of racing, scrambling and trials. A great deal of interest was generated and the necessary 100 machines for it to be eligible for the Clubman’s TT were in the hands of customers by March. In total 21 machines were entered and the winning bike was a Goldstar ridden by Harold Clark at an average speed of 75.18mph. This began a period of utter domination in which a Goldstar won the event for the next seven years until the 350cc Clubman’s class was abandoned in 1956.

Quoting from factory records, this particular machine was a ZB32Competition consigned to Balfour Williamson, London EC3, on 4th January 1951, BSA tally number 2833. Normally the standard frame was a plunger sprung one but this was one of the few supplied to special order in a rigid frame. A copy of the original spec for this engine from the BSA works is included in the history file and shows special racing cams, springs, piston and TT carburettor.

This machine belonged in the 1990s to BSA Goldstar Owners Club technical officer, Brian Shackleford, the current owner acquiring it in 2004. The engine features now include: a TT carb; close ratio gearbox; racing cams 65-2442 inlet and 65-1891 exhaust; 10 degree 1/2 timing pinion;DB32 valves and belt drive primaries. It was used for vintage racing and sprinting and features a 16-tooth gearbox sprocket and the dynamo removed.

A new dynamo and 20-tooth gearbox sprocket are included as well as the original crankcases which have been repaired but not fitted to the machine – those currently fitted are a replacement pair stamped up with the original number. This machine has been stored for the past three years and will need a precautionary check-over before use although the carbs were cleaned up and fresh fuel added just before the sale and it started and ran well.