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Lot 431: 1955 BSA 499cc Gold Star Replica Trials Outfit

Collectors' Motorcycles, Bonhams (16 October 2005)

This trials sidecar outfit was originally constructed in the mid-1950s by the proprietor of Atkinson Motorcycles, of East Ham, London and purchased from his widow by the vendor around six years ago. Since acquisition, the machine has been totally rebuilt using mainly new parts, and has not been used since its completion earlier this year. The engine - which is lubricated by Castrol R - comprises a BSA B31 bottom end fitted with a 500cc Gold Star cylinder barrel and ’head. We are advised that on strip down it was found to be in remarkably good condition, merely requiring new valve guides and piston rings. The frame and sidecar chassis have been powder coated and the wheels rebuilt with new rims and spokes, while the BTH competition magneto has been reconditioned. The aluminium-panelled trials ‘chair’ bolts to the modified BSA frame, while unusual constructional details include sidecar wheel suspension linked to the bike’s swinging arm, and chassis tubing that doubles as the exhaust system to save weight. Frame and engine numbers both date from the 1955 model year, raising the possibility that this is a ‘matching numbers’ machine.

Lot Details
Auction Collectors' Motorcycles
Bonhams, Classic & Motorcycle Mechanics Show, Stafford
TypeMotorcycle
Lot Number431
Estimate£3200-£3800
Outcome SOLD
Hammer Price£2600
Hammer Price (inc premium)£2990
Year1955
Condition rating
Registration number
Mileage-
Chassis number
Engine number
Engine capacity (cc)
Engine - cylinders
Number of doors