PURPOSE: A classic bike is provided to help the remedical exercise of arthritis patients as a part of physical therapy.CONSTITUTION: A classic bike comprises a rubber track, a roller chain, a controller, and a parking brake. In order to increase the elasticity and strength, environmentally-friendly materials such as inner wires, cotton yarn, etc which are not melted or burned at high temperatures are added in a rubber material. The classic bike is manufactured by stainless steels and reinforced plastics.COPYRIGHT KIPO 2013.