Bradshaw Motorcycle Engines
Brief History of the Marque: Bradshaw
In 1912 Ronald Charteris founded the All British Engine Company in Hersham, Surrey with Granville Bradshaw as chief engineer, and later changed the name to A.B.C. Motors, Ltd. During the Great War they produced horizontally opposed twins for Sopwith, and used a development of this engine in a motorcycle in 1918, pre-empting the BMW design by several years. (Bradshaw was not amused by BMW's use of his design and took them to task in 1926. This would not be the last time BMW "acquired" a British inventor's design.)
The Sopwith Aviation-built ABC flat-twin was a 398cc ohv with wet sump lubrication and a four speed gearbox. It was a very advanced motorcycle which sported a duplex cradle frame, front and rear suspension and internal expanding drum brakes. Gnome & Rhone produced an improved 493cc version of this machine under license until 1925.
Bradshaw engines included an oil cooled 350cc engine and the Omega rotary.
There is an article by Roy Bacon on the very unconventional Omega here:
There is a fairly humorous account by Patrick Head of testing one of
these engines here:
Fri Oct 05 2012
have a friend with complete engine.it turns over.is it worth much.think it is the oil cooled 350..
Tue Feb 06 2007
pflowbikes at worldonline.co.za
Bradshaw 350cc oil-cooled
I have been given a 1920-era Bradshaw 350cc oil-cooled engine. It has unfortunately broken a con-rod and damaged the engine casings. It is therefore missing a con-rod, and it's also missing the tappets and pushrods. Otherwise, everything is there. I would like to know if you could put me in touch with anyone who may have a spare Bradshaw engine casing or any other parts from an engine they are breaking up.
Durban, South Africa
Thanks for your prompt response - something we're not used to in South Africa!
I do have some pix and have attached them.
A little bit of tech info. - I don't know if you keep records such as this, but I have noticed that a few websites state that the Bradshaw oil-cooled engine had a pressure-fed big-end and that the sleeve was cooled by splash-feed from the crankshaft. In fact, the exact opposite is true - the engine has a splash-fed plain bearing big-end (white metal bearing) with a scoop in the con-rod, and the oil pump exists only to pump oil from the sump into an annular groove which runs around the top of the sleeve. The engine being a wet-sleeve design, the oil simply ran uniformly down the outside of the sleeve and dripped back into the sump.
I appreciate your help in the matter - thank you!
If you have a query about Bradshaw Motorcycles, or wish to share your knowledge of these classic British machines, please leave a note in the forums