1973 BSA 499cc B50-Powered Trials Combination

BSA unit-construction engines started with the C15, which was produced in various forms, and was enlarged to 350cc in the creation of the B40 in 1961. A further capacity jump to 440cc came with the B44 incarnation, which was used by Jeff Smith to great effect in scrambles competition, and spawned a number of various competition-oriented models, culminating in what was to be the ultimate unit single, the B50, announced in late 1970, it had been stretched to 500cc and produced in road and off-road versions. All had the new oil-bearing frame. Eric Cheney had been a successful motocross rider in the 1950s, until he found his talent for frame-building and machine preparation. This formed the rest of his career, building frames and bikes predominantly for off-road competition machines which achieved great success.

TUR 60M was acquired by the present owner in 2005. It was always referred to as a Cheney BSA, although there is no documentary evidence to support the frame being a Cheney. Indeed, there is a suggestion in correspondence in the history file that the bike may have been a complete solo ex-works B50 scrambler. The machine was known to the vendor for many years, and was purchased from his friend Stan Ward. Stan had bought the bike in 1976 from Jack Hubbard Motors in Braintree, Essex (purchase invoice on file). The machine is believed to have been built by Jack Lee, who was an Eastern Centre Trials Champion in the 1960s, and later turned to sidecars; hence the frame and engine number prefixes of JL. The engine is reputed to be an ex-factory unit (or bike) obtained by Lee from BSA factory rider Dave Nicoll, who lived in Essex. Nicoll was a BSA team mate of John Banks, who campaigned a Cheney B50 in the 1973 and 1974 World Motocross Championships. The front hub is a Victor-type with a works-type brakeplate, and the front forks appear to be Cheney-type. The outfit was used in trials by Stan and his son for a time, before it was loaned to a relative, who unfortunately seized the engine. Thereafter, the BSA was stored unused until purchased by the vendor, who intended to restore the machine. Unfortunately, the work was never started, and realising that he will not get around to it, the vendor has decided to pass the project on to a new owner with sufficient enthusiasm to complete it.

Documentation includes a current V5C, the aforementioned purchase invoice, correspondence with the BSA Owners club, and photos of Stan Ward and the machine competing in trials.
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