Sturgis Rally
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Originally posted by Buck Lovell on Monday, 23 January 2012 in Buck Lovell's - American Biker Blog


Way back in the early 1930's a man named Albert Crocker, who owned an aluminum foundry in Los Angeles California decided to build single cylinder Speedway motorcycles to compete with the then dominant Indian and Harley-Davidson machines. Speedway bikes have no brakes, and were very fast on the 1/8 mile tracks of Southern California. His Crocker Speedway motorcycles so thoroughly trounced the competition, that a demand was created for Big Twin models to be sold to customers and ridden on the street. Albert Crocker built the first Crocker Big Twin "Big-Tank" model in 1936. As the popular story goes, Mr. Crocker sold approximately 64 Crocker Big Twins, both Big-Tank and Small-Tank models, and he actually lost $2500 in 1935 era money on each sale. He was trying to build a legend, a super bike that was faster than the existing Harley-Davidson and Indian machines. He succeeded in Spades. His Big-Twin motorcycles were an honest 10-15 MPH faster than either the Chief or the HD EL models, and this in showroom condition. Of course ALL Crocker Twins were custom ordered. The only reason the Crocker motorcycle faded away was because of World War Two. The United States of American needed aluminum and aluminum components more than we needed another motorcycle company. Mr. Crocker was advised by the War Department that the US military required the services of Albert Crocker's aluminum foundry for essential war production.

I spent several years photographing most of the surviving Crocker motorcycles about 20 years ago. Somewhere in the neighborhood of 14-16 twin cylinder Crocker motorcycles survived out of the approximately 64 produced prior to the war. One or two Big Twins were assembled illicitly during the war using existing parts and components. I have complete photo sets of 14 of these machines, including Chuck and Tom Vernon's 1936 #1 Crocker Twin seen here, as well as their Maroon 1941 Big Tank model. As pictured the cylinder heads on #1 are not correct. The original cylinder heads had open (uncovered) valve springs. The first Crocker twin had hemispherical combustion chambers with open valve springs, but that design was replaced by a squish type combustion chamber after the first hemi designs proved impractical. The first 500 Harley-Davidson EL's of 1936 also had this open valve spring design flaw. Number 501 HD EL (61 inches) and number 2 Crocker Twin (80 cubic inches I was told) both had enclosed rocker arms and valve springs, which is the only way to keep any valve train clean and protected.

The Crocker twin transmission is/was a three speed crash box with a cluster gear on the bottom shaft, and a slider gear with dogs, which slid on the splined main shaft traversing the top of the gear box.The transmission was hand shifted, the clutch was foot operated. There were/are no synchros, so careful shifting the rule of the day. The Crocker gear train in the transmission is so robust there has never been a failure of the Crocker gearbox, at least none that that I could discover. The gears are the size of typical tractor components.

At any rate the Crocker Motorcycle Company has been reestablished, and is producing parts and components to allow you and I to build a Crocker motorcycle. Check out their website, it has ton American motorcycle history with photos that are worth a look.


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