Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,366 pages of information and 233,846 images on early companies, their products and the people who designed and built them.
of St. Nicholas St, Coventry
1896. The Riley Cycle Co was registered on 25 June, to acquire the business of the Bonnick Cycle Co.  This was instigated by William Riley, (Junior) in conjunction with his brother, Herbert John Riley, and his brother-in-law Basil Riley. Some of William's sons, who joined the business subsequently, took the lead in developing motorised transport.
Riley Cycle Co was a public company
1898 A fire destroyed much of the company's No. 1 factory
By 1899 Percy Riley produced a prototype four-wheeled quadricycle.
1900 The cycle business continued to make losses. Rileys sold a single three-wheeled automobile.
At first, the small engines fitted to Riley Cycles were obtained from specialist engine manufacturers but the desire to design and produce their own engines was strong
1902/3 the Riley Engine Co was established, also in Coventry, by three of William's sons Victor, Percy and Allan. They patented the mechanically operated inlet valve. The head of the new company was William Riley's son Percy, who at the age of 20 was already a practical and ingenious engineer who had successfully built his first car before his 18th birthday. At first, he simply supplied engines for Riley motorcycles, but the company soon began to focus on four-wheeled automobiles.
1905 Their Vee-Twin Tourer prototype, produced in 1905, can be considered the first proper Riley car.
1906 Having outgrown its original site, the Riley Engine Co. moved into new premises in Aldbourne Road, which it and its successors were to occupy continuously until 1974.
1907 they announced the first ever detachable road wheel, designed by Percy. These wheels became an important part of the company's business as demand became worldwide, 183 manufacturers paid to use the patent rights.
1907 Riley halted motorcycle production to focus on automobiles. The focus of interest moved from motor cycles to motor cars
1908 Riley offered 2 cars - the 9 and the 12/18.
1910 October. details of the 10hp and the 12-18hp cars.
1911 Bicycle production ceased.
1912 Listed in Spennell's directory of Coventry as Cycle Manufacturers. 
1912 the Riley Cycle Company changed its name to Riley (Coventry) Limited as William Riley focused it on becoming a wheel supplier for the burgeoning motor industry.
1913 The younger Rileys established Riley Motor Manufacturing Co also in Aldbourne Road.