Hercules Motor Bicycle. I bought this Hercules motorized bicycle four months ago it was geared to run 50 to 65 but is now geared for 15 to 20. I changed the rear sprocket and added a new chain and cable as well as a seat. The bike was stripped to the frame and sandblasted. Added new bearings and seals. Newly built 3 speed rear wheel hub. Front and rear pull brakes. It's a good ride with or without the engine running. 75 miles per tank of gas. About 150 a gallon. 2 Cycle engine needs a 20 to 1 oil mixture.