Cotton 1938 490cc OHV JAP Model 500/38 frame # 26135 engine # KOZ/O 60221/SJ
The Glouchester-based Cotton factory was one of many small manufacturers that used proprietary engines in the years between the first and second world war. But there was something quite special about the Cotton, that made it much more successful than most other small makes: its frame. The frame that Frank Willoughby Cotton designed around 1914 was of triangulated construction, very light and exceptionally strong. Cotton was studying law at the time, but after WWI he decided to become a motorcycle manufacturer. In 1922 Cotton entered three machines for the Junior TT; an unknown young Irishman by the name of Stanley Woods rode his Cotton to an impressive 5 th place, despite a number of alarming mishaps during the race such as the machine and rider catching fire during refuelling!
The next year Woods rode again for Cotton and he scored his first of 10 TT victories, being only 19 years old. Cotton had proved the very good roadholding and cornering qualities of his bikes and the make was to win many more races. In the years after WWII Cotton left the triangulated frame principle and scored successes in moto-cross and road racing.
The JAP engine number coding for KOZ/O/60221/SJ works out as follows:
K = 490cc, 85.7 x 85mm bore and stroke
O= Overhead valves
Z = Dry sump lubrication
/O = 1938
/S = made to the customer’s specification
J = Roller-type cam levers and exhaust valve lifter
The 1938 Cotton range was exclusively sold via Pride &Clarke in London and comprised no less than 14 models. They were fitted with s.v. and o.h.v. JAP engines, o.h.v. Blackburne engines or two stoke Villiers power sources. The machine we present was one of the top models in the range, capable of some 80 mph and fitted with Burman gearbox, enclosed valve gear and dry sump lubrication. This sturdy and well-built Cotton is an older restoration that has been stored for some time. It is in running condition but will benefit from a good checkup.