1937 - Official Model Range Overview
By 1937, Cotton had refined its identity around overhead-valve sporting machines while still offering practical side-valve options. A total of 14 models were produced, covering a wide performance spectrum.
Model Categories – 1937
- 250cc Side-Valve (SV)
- 250cc Overhead-Valve (OHV)
- 350cc OHV
- 500cc OHV
- 600cc OHV
250cc Side-Valve
Reliable and mechanically simple, the SV models offered smooth torque and practicality for everyday riders.
250cc OHV
A more performance-oriented lightweight machine, ideal for sporting road use and club competition.
350cc OHV
The core of the Cotton range — balancing power, agility, and the rigidity of the triangulated frame.
500cc OHV
Strong mid-range torque and high-speed capability for experienced riders.
600cc OHV
The largest capacity offering, delivering commanding performance while maintaining Cotton’s trademark handling precision.
600cc OHV 1938
The 1938 range maintained:
- 250cc OHV and SV models
- 350cc OHV sporting machines
- 500cc OHV high-performance variants
- 600cc OHV flagship models
The emphasis remained clear: performance through balance and structural integrity rather than sheer engine displacement.
The triangulated frame, now fully matured in its design, continued to define Cotton’s road-holding reputation.
500cc JAP 1939
The Final Pre-War Catalogue
In 1939, Cotton produced a range of 14 models, covering capacities from 150cc to 600cc.
150cc Lightweight Models
Economical and accessible, the 150cc machines were aimed at new riders and daily commuters.
Some variants used Villiers two-stroke engines, while others featured small-capacity overhead-valve units.
Lightweight, agile, and mechanically simple, they retained the triangulated frame philosophy even in entry-level form.
250cc Models (SV & OHV)
The 250cc class remained important to Cotton’s identity.
250cc Side-Valve (SV)
Durable and easy to maintain, these machines provided smooth torque and reliable road performance.
250cc Overhead-Valve (OHV)
More sporting in nature, the OHV variants offered sharper throttle response and improved performance for enthusiastic riders.
350cc OHV
The 350cc overhead-valve machines represented the core of the Cotton sporting range.
Typically powered by JAP or Blackburne engines (often 348–349cc actual capacity), these motorcycles delivered:
- Strong mid-range torque
- Excellent road holding
- Balanced performance for touring or club competition
This class best embodied Cotton’s engineering philosophy.
500cc OHV
The 500cc machines (often 490–496cc actual displacement) offered greater torque and high-speed capability.
Designed for experienced riders, they combined powerful proprietary engines with Cotton’s rigid chassis geometry.
600cc OHV
The largest-capacity models in the 1939 range featured 596cc engines.
These machines were the most substantial and powerful civilian Cotton motorcycles produced before wartime interruption.
They represented the pinnacle of pre-war capacity within the marque.