The 100 mph (160 km/h) Excelsior 7-S. C. (Short Coupled) racer from 1913. This rare racer is completely original and “barn fresh”, only the two tires, two plug leads were renewed. The motor is ported and was tuned for speed by the Excelsior factory. The cylinders were ported for improved exhaust and cooling. The porting was accomplished by a series of holes, drilled in the cylinder just above bottom dead centre of the piston travel. Besides allowing more exhaust the ports provided an additional benefit of more rapidly filling the combustion chamber with the next incoming fresh air charge 7-S. C. was one of the fastest motorcycle between 1911-1914 and forced Indian to develop the 8-valve racer.
So far this is the only original surviving racer which is know!
© Copyright American X Archive,Thomas Bund