Al was a very capable engineer and designer, and started the manufacture of the Crocker 30.50-cubic-inch single-cylinder speedway bike, which was used successfully by many of the best riders on the Pacific Coast when speedway racing was at its height. He built 31 speedway bikes, and gave the J.A.P.-powered bikes a lot of tough competition. About 1936 he decided to build a 61-inch, overheard-valve V-Twin, and this was developed by Mr. Crocker in his own machine shop, assisted by well-known rider P.A. Bigsby, who was also a pattern maker. Crocker had more orders than he could possible fill for the Crocker Twin, which was definitely the best motorcycle produced in this country at that time. According to Bigsby, 64 Crocker Twins were built.