Cedos motorcycles were produced from 1919 to 1929. The name was derived from those of the brothers, Cedric and Oscar Hanwell.
1919 Just after the end of World War I, the company entered the market with ladies' and gents' lightweight motorcycles powered by their own 211cc two-stroke engine. Both models had a chain-driven, two-speed gearbox and belt final-drive. The ladies' model had an open frame and both required push-starting. See article on the 1919 Cedos.
1921 They added a 257cc model, again in both ladies' and gents' versions.
1922-1923 Only the larger model was listed. Following liquidation, the company had to be restructured.
1924-1928 New models were added with a variety of engines. At various times they used Blackburne, Bradshaw and JAP and for their last two years they used Villiers. Gearboxes became three-speed Sturmey-Archer with all-chain drive.
A report on the Motor Cycle Show of November 1924 reads, in part:
British Engine Builder
Fitted to numerous British and European motorcycles.
Cedos Engineering Co., Ltd., Northampton.
Wed Jan 19 2011
tgreenfellaccountant<at>btinternet dot com
John Granville Grenfell
Dear Sir, my grandfather rode a cedos in european races and I have a medal he won during the 1920s
my grandfather was indeed John Granville Grenfell MSAE FMI he rode cedos motorcycles on the continent during the 1920 when he owned the motor house in Bellenzona in switzerland and sold motor cycles. there are articles on him in various magazines. Yours Sincerely Anthony Granville Clarke-Grenfell
John Granville Grenfell was born in 1893 in Sydney, Australia. He was the grandson of John Granville Grenfell (1826-1866), the Gold Commissioner murdered by bushrangers at Emu Creek, New South Wales in December 1866.
'JG' or 'Jack' Grenfell, as he was known, came to England in 1906 and in 1907 he was taken by his father to the opening car racing meeting at Brooklands. He became 1st violin in the Queen's Hall Light Orchestra, spoke several languages fluently and was a judo Black Belt.
His first love was motorcycles which he began racing around 1909 and won several Swiss circuit events.
In 1915 Jack Grenfell married Minnie Tully, a very well-known motorcyclist and mechanic in her own right with a penchant for large and powerful bikes and their marriage proved to be a perfect partnership.
On 26th November 1975 at the age of 84, having felt unwell at his workshop he rode his motorcycle to Weybridge Hospital. He died shortly afterwards.
Jack was later considered to be one of the most respected and innovative engineers of his generation.
Extract (edited) from grenfellhistory.co.uk
Other references: Portrait of a Perfectionist, Denis May, Motor Cycling August 1961.
We extend deep sympathy to Jack Grenfell in the loss of his wife, Minnie Grenfell, formerly Minnie Tully, who rode 90-bore B.A.T.-J.A.P.s, Matchlesses and Indians with the best of the motorcyclists of those days. She remained a keen motor-cyclist all her life, assisted her husband at his Brooklands workshop and mothered all the lady riders who ventured on the Track. Her many friends have suffered a very great loss.