If you ride chain for a long time, it is recommended not arbitrarily replace the flywheel, the flywheel will be replaced with a new tooth jump jump chain phenomenon, affecting normal riding. Solution or a flywheel to replace the old chain and old together, in method two jumping tooth jump of the chain of force riding a period of running, running time is long or short, according to the chain's wear different.

• Speed: 7 Speed Teeth: 14-16-18-20-22-24-28T Steel Flywheel
• Weight?About 550g
• Specifications: the inner diameter of wire lines:34mm