[5] Designed around an unusual crank in which the central flywheel had a narrow section but large diameter, the new engine gained a reputation for oil leaks and unreliability.

[2] After Hopwood changed the crankshaft material from cast to nodular iron and improved the gearbox layshaft bush, the Jubilee proved more reliable and sales slowly increased.

The front frame tube was a steel pressing and the lightweight forks, brakes and wheels were Francis-Barnett parts.

The gearbox was the same as in the AMC 2 stroke Piatti engine and the AJS and Matchless lightweight motorcycles.

An estimated 5,000 Jubilees were built at Norton's Bracebridge Street works before production was transferred to the AMC Woolwich factory in 1963.