Crocker Motorcycles

[2] Crocker next designed an overhead-valve conversion kit for Indian 101 Scout V-twins, intended for dirt track racing.

Subsequent limited production of the OHV Indian kit in 1932 used a reduced engine capacity of 500cc to comply with AMA racing rules.

The official AMA magazine The Motorcyclist (December 1930) noted the debut of the Crocker Speedway motorcycle: "…two spotless and keen pieces of racing equipment surely worthy of the best the country had to offer as their pilots.

His speech was short, brief; just the sort of thing that the situation called for…He was glad that they [the bikes] were good…They would be better.” Crocker later (c.1933) designed and built a prototype of an experimental overhead-camshaft single-cylinder speedway racing engine, with a chain-driven camshaft.

[4] In 1934–35, working with Paul Bigsby, Crocker designed a new overhead-valve V-twin with 61 in3 (1,000 cc) engine, initially with hemispherical combustion chambers (Hemi head)producing 50 hp, making it one of the most powerful motorcycles in the world, and exceeding the horsepower of rivals the Indian Chief and Harley-Davidson EL 'Knucklehead'.

Crocker Motorcycles had no manufacturing capacity, and used Paul Bigsby's technical drawings to outsource production of parts: aluminum fuel tanks, crankcases, and footboards, steel gears, shafts, and flywheels, etc.

In 1940, Crocker advertised a new machine, the Scootabout scooter,[7] using a Lauson TLC sidevalve engine of 2.3 hp, with an automatic (CVT) transmission.