From Graces Guide
of XL Works, Gosford Street, Coventry, makers of cycles, motorcycles and cars.
1886 Formed as Calcott Brothers and West in East Street, Coventry with William Calcott, his brother James Calcott and Enoch John West as partner. The company made XL cycles from their premises in Much Park Street, and subsequently Far Gosforth St Works.
1891 Offering eight models.
1896 The company was registered on 29 August, to acquire the business of cycle manufacturers. 
1911 Added a 1.5hp model with an inclined engine mounted in a loop frame, with belt drive and sprung forks.
1912 The range comprised a 2.25hp, 237cc lightweight; later joined by a stretched 2.5hp, 292cc model.
1913 Both those models continued. Some used their own 249 / 292cc engine.
1913-1917 For a list of the models and prices see the 1917 Red Book
1914 The 2.25hp model was still listed together with a 2hp model fitted with a 170cc Precision engine that had ohv set horizontal to the cylinder, a two-speed gearbox built in-unit with the crankcase, belt final-drive and Druid forks.
1915 Only the 2.25hp model was listed. It was the last year of production.
1919 January. Advert for the Classic Light Car by Calcott Brothers of Coventry. 
1921 L. J. Shorter appointed as Chief Engineer
Sources of Information
-  Gazette Issue 26218 published on the 30 October 1891. Page 18 of 56
- The Stock Exchange Year Book 1908
- Peck's Trades Directory of Birmingham, 1896-97: Cycles
- The Autocar of 4th January 1919 p10
- British Motor Cars 1950/51
- The British Motorcycle Directory - Over 1,100 Marques from 1888 - by Roy Bacon and Ken Hallworth. Pub: The Crowood Press 2004 ISBN 1 86126 674 X
- The Encyclopedia of the Motorcycle by Peter Henshaw. Published 2007. ISBN 978 1 8401 3967 9
- Coventry’s Motorcycle Heritage by Damien Kimberley. Published 2009. ISBN 978 0 7509 5125 9
- 1893 Calcott Bros ‘X.L. Full Roadster’ Solid-Tyred Safety Bike