Pocket Sized Frame
How to Build a Pocket Bike Frame
The engine in the plans is a 3/4-hp Olson and Rice engine (now manufactured as O&R) mounted on an 1/8-in. sheet of aluminum. This is made for some agricultural operations.
But any small engine will do.
The aluminum sheet in turn is attached to the frame with four 4-1/4" . U-bolts. (The bolts permit quick adjustment of the chain tension.) Depending upon the rider's bulk, the little bike may or may not take a steep hill. On occasion I've had to dismount and tote her up a hill under my arm.
To make it, you'll need at least 12 to 15 ft. of 5/8-in. thin wall tubing- for the frame. Build the frame in two sections and, for strength, join them with 5/8-in. steel pins inserted in the tubing at the joints. Where the pins cannot be used, wrap steel bands around the frame and braze for added strength. The brackets which support the rear wheel are bent into a U-shape, slipped into the frame and brazed.
The handlebars are two pieces of the thin wall tubing joined in the middle with two pieces of metal 1/8 x 1-1/2" x 5". spaced 3-1/4". apart. The latter are drilled out at center to receive the 5/8 x 4-1/2", bolt which serves as the turning spindle. To receive the front axle, the ends of the forks are flattened and drilled. To complete the front fork, bend the upper portions to form the handlebars. For leg clearance, bend forks slightly forward.