1960 BSA 650cc A10 Golden Flash

BSA’s A10, introduced in late 1949, was a development of the Bert Hopwood-designed 500cc A7 with vertical parallel twin architecture, with 360-degree crankshaft and single camshaft at the rear of the cylinder block. Power went through the same 4-speed gearbox, while all cycle parts remained identical between the two models, but for a larger front brake on the larger of the siblings. By the end of the 1950s, the rugged 650cc twin had undergone considerable development. On the cycle parts front, the introduction of a swinging-arm frame in 1954 had resulted in the original bolt-up gearbox’s replacement by a conventional separate item, while the engine had benefited from numerous improvements including an increase in compression ratio for 1958 and the standardization of the sports models’ high-lift camshaft for 1959. The Golden Flash continued in production until superseded by the new unitary construction twin in 1962.

The motorbike offered

The 1960 BSA 650cc A10 “Golden Flash” offered here, comes to us from a Northern California collector, and enthusiastic restorer. Purchased in 2015 from an East Coast seller, who purchased the bike to keep in his living room as a rolling work of art. When he took delivery, the fit and finish were indeed beautifully and professionally done, but the bike needed the usual re-commissioning to return it to regular road use. He took it to Raber’s in San Jose, where Bob Raber found the engine to be seized. Bob, Paul Hudson and the Rabers gang were given the greenlight to rebuild the engine completely and add any upgrades to make it as reliable a rider as possible. The fuel tank went to  GTL Advantage in Los Angeles to be cleaned and relined, since there was some rust present from lack of use. Several months and approximately $11,000 later, what has been credited by several “in the know” riders as one of the smoothest and cleanest A10’s they have ever seen and ridden.

The rebuild included:

• Rebuilt crankshaft assembly
• Cylinders re-sleeved and bored to standard size
• New pistons and rings
• New valves, valve guides, springs and hardened seats compatible with modern gas
• Transmission gone through and fully checked
• Cam pate reversed for more conventional one-down, three-up shift pattern
• New SRM dynamo belt drive
• New 12V generator and DVR regulator, new coils
• BTH electronic magneto
• Boyer Branson electronic ignition
• New Amal Premier carburetor
• SRM sump kit and oil pump
• Rebuilt forks with new damping rods
• New Dunlop K70 tires installed in October of 2022 (with less than 600 miles to date)
• Complete inspection, tune up, brake inspection, compression check, head torque, valve adjustment and carburetor tune performed in October of 2022

Now, with 2,500 miles on the odometer, reset during the restoration, everything works as it should, including lights (high and low beam), horn and brake light. It starts easily, shifts “like butter” according to our vendor and runs beautifully. It is indeed a motorcycle worthy of both showing and reliable riding.