Donut is a circular frame folding bicycle concept in which the Handle, saddle, pedals and the wheels folds inside the circular frame with no parts of the bicycle protruding outside the frame. Unlike the existing folding bicycles, which fold about the triangular frame and most of the bicycle parts stick out and make it difficult to carry or stow. The main intention was to design a compact, lightweight folding bicycle, which can be carried in bus/train or stowed in the car trunk.
This bicycle has a circular aluminum alloy welded frame, which takes the load of the rider. The front and rear forks are pivoted to the circular frame and a tubular pedal slides as well as rotates inside the crank bar bearing. Combination of chain and gear drives ensures that the rear wheel rotates in right direction and easy to fold. A handle is provided at the top for ease of carrying. The circular plastic enclosure (white) is mounted over the circular frame, which encloses the saddle, handle and pedals after folding.
Thanks: Designer Arvind, Mechanical Engineer, Banglore, India,