1976 Norton Interstate Mk III Electric Start (828cc parallel twin)
58 bhp, 430 lbs, 115 mph
Norton motorcycles were manufactured for 75 years from 1902 to 1977. Initially by the family business, then from 1953 as part of AMC and from 1966 as part of Norton-Villiers and finally Norton-Villiers-Triumph, till its bankruptcy in 1977. The marque was defined by the incredibly successful Manx Norton racing singles, the Featherbed framed Dominators and the Isolastic (vibration free) Commandos.
Development of the Commando stemmed from the need to counter the Japanese invasion as well as expectations of multi-cylinder bikes from BSA and Triumph. Due to economic circumstances it was not feasible to develop a brand new engine. Hence the 746cc Atlas engine (itself the ultimate expression of the 1949 500cc Dominator engine) was used. This was a 360 degree parallel twin (both pistons move together but fire on alternate strokes) which when conventionally mounted resulted in unacceptable levels of vibration. Thus the design team chose to eliminate vibration by hanging the engine, gearbox and swinging arm in rubber bushes thus isolating (branded Isolastics) them from the main frame and rider. The package was further enhanced by some fairly radical styling. The Commando was unveiled in September 1967 as a bike with the power characteristics of a big twin combined with the smoothness of a multi-cylinder. Despite still being a non-unit engine and gearbox, having only a four speed gearbox and without an electric start, the bike was very well accepted and built a loyal following which was further enhanced by racing success.
There were three main models – Fastback, Roadster and Interstate. The latter (with a large 5.2 gallon tank) was introduced in 1972 with a focus on the US long distance rider. In total some 80,000 Commandos were built.
As from 1973 the Commando’s engine was bored out to 828cc. The intention was not more power, but rather greater reliability (compression reduced from 8.7 to 8.5:1). Between 1975 and 1977 some 1,530 Mk III Commandos were produced with electric start, left hand gear shift, Lockheed discs front and rear and allowance for Vernier adjustment of the Isolastics. These were the final Commandos produced.
This bike is a replica of the 1976 Mk III Interstate ES built during 2013 by Norvil Motorcycles. It has a few enhancements to the original specification and a bespoke colour scheme.