1921 ABC 398cc TT
The Automobile Magazine 'Oily Rag' Reserve Collection; advanced design by Granville Bradshaw; built by Sopwith Aircraft
Company; ideal lightweight Banbury Run mount
Designed by Granville Bradshaw and produced by the Sopwith
Aircraft Company, the ABC drew heavily on its designer's wartime experience in
the development of air-cooled aero engines.
A ground-breaking design, the ABC engine was a 398cc
overhead-valve flat twin with integral four-speed gearbox. Legend has it that
the power unit was designed in under three weeks, but Bradshaw did not stop
there, going on to pen the duplex loop frame and sprung front and rear forks
that marked out the ABC as one of the most advanced motorcycles of its day. It
was fast too, JLE Emerson breaking the one-hour record twice at Brooklands, the
second time at an average speed of 70.44mph, a feat that necessitated exceeding
80mph on occasions.
Despite these successes, this promising design was
hamstrung by production difficulties and price increases, only 3,000 or so being
made up to 1921 when the Sopwith factory ceased manufacture, though production
of a modified version was continued by Gnome & Rhone in France.
Dating from 1921, this ABC was acquired for the Oily Rag
Collection in March 2007. During the current ownership it has been
sympathetically rebuilt with invoices showing various new parts including:
piston rings; brass rear trailing arm bushes; headstock bearings; fork bushes;
control cables; long reach spark plugs and two new tyres. In addition, the
wheels have been rebuilt with new rims and spokes.
It comes with a good amount of technical literature
relating to ABC but there is no V5C and the registration number currently on the
bike does not seem to be linked to this machine on HPI/Experian.
For more information contact James on 07970 309907 or