Interest in European-style speedway had exploded in the USA after its introduction by Lloyd "Sprouts" Elder during 1931. Several high school sports fields in the Los Angeles area had been turned into speedway tracks during the summer vacation. Local Indian dealer, Albert "Al" Crocker was fascinated with this new sport, so, in partnership with his chief engineer Paul Bigsby, they decided to build their own speedway bike. The initial 1931 prototype was a special Crocker frame into which they installed a regular 45 cubic inch (750cc) sidevalve Indian 101 Scout engine. Satisfied with this frame design, Crocker next turned his attention to a better engine, so for the 1932 campaign several Scout engines were converted into 30.50 cubic inch (500 cc) overhead valve units.
1931 OHV Crocker Indian V-Twin
The first of the Crocker-powered overhead valve singles appeared at Emoryville Speedway in California in November 1933. Cordy Milne rode the machine in twelve races and took nine first places and one second place during the meetings held on November 11th and 14th. His brother Jack had four first places during the same two meetings. Other top riders who used the first Crocker dirt trackers were Miny Waln, Earl Farrand and Snooky Owens, so the marque was well represented.
Unfortunately for Al Crocker, the British J.A.P. powered bikes were beginning to dominate speedway in Europe and were rapidly replacing the Douglas and Rudge machines which had dominated the sport since 1928. The 40hp Crocker proved itself the equal of the Rudge, and was superior to the Harley-Davidson CAC. However, the J.A.P. machines were good for 42-43 hp, so Crocker's new baby needed further development to be competitive. He therefore had two overhead cam motorcycles built during 1934, one of which was ridden a few times by Miny Waln. The 1934 Crocker catalogue stated....
"These machines competed continually at Long Beach, San Diego, Los Angeles, and Santa Ana. In the winter they were sent to Mexico City for a series of eighteen races, where practically every event was won by a Crocker machine. Competition with the imported equipment forced the decision in favour of a newly designed power plant - a type which would have acceleration, the right power output, low cost of maintenance plus a low first cost. A single cylinder type was decided upon."
"These machines competed continually at Long Beach, San Diego, Los Angeles, and Santa Ana. In the winter they were sent to Mexico City for a series of eighteen races, where practically every event was won by a Crocker machine. Competition with the imported equipment forced the decision in favour of a newly designed power plant - a type which would have acceleration, the right power output, low cost of maintenance plus a low first cost. A single cylinder type was decided upon."
Meanwhile, Crocker's attention was turning to a long cherished dream of building the fastest road-going motorcycle in the nation - perhaps the world. Facing stiff competition from the J.A.P. engines, and not being a true factory owner, he abandoned his shop-built speedway bikes at the end of 1934 to launch the far more famous Crocker v-twins which debuted in 1936. During the speedway project, the Crocker machine shop had built between forty and fifty of the pushrod speedway motorcycles.
Key specifications of the 1934 Crocker speedway machine:
Bore: 3 1/4 in (82.55mm)
Stroke: 3 5/8 in (92.085mm)
Displacement: 30.06 cubic inches
Compression Ratio: 14 : 1
Crankpin: 1 1/8 in, drilled for oil
Main Shafts: 1 in, with 7 degree taper
Bearings: roller for mainshafts and crankpin
Valves: 1 3/4 in, set at `close angle' in `shallow domed interior'
Valve Springs: three coil springs per valve
Ignition: gear driven Lucas magneto
Carburetor: two bowl Amal
Power Peak: at 6,000 rpm
Fuel: alcohol
Frame: chrome molybdenum tubing
Gear Ratio: for 1/5 mile track, 8.75 : 1
Weight: 235 pounds
Cost: $385
Information taken from the Book "American Racing Motorcycles" by Jerry Hartfield.
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