I now own two of these bikes. Both have developed a clicking noise when pedaling in middle gears. One click per rotation. Bike shop says it's a bearing problem in the free wheel. The black bike does not come with a derailer guard, protector. When laying down in car trunk on side this can become a problem. Also black bike has much more play in frame hinge than the silver one. I still like the bikes can still ride with clicking but should not have this problem. Update replaced the free wheel on one bike clicking gone. Free wheel was rocking side to side when I took rear wheel off. New free wheel no rocking.