The Schwinn Bonafide Mountain Bike features an aluminum mountain frame and a powerful Schwinn suspension fork that soaks up bumps and thumps to provide you with a fun, durable riding experience 24-speed Shimano EZ-Fire trigger shifters and front and rear Shimano derailleurs make gear changes easy and smooth Front and rear mechanical disc brakes provide crisp all-condition stopping out on the trail. Durable Schwinn alloy cranks provide steady gearing and less pesky maintenance High-profile double wall alloy rims are light and strong for added durability. 2.25-inch wide knobby mountain tires are ready for bumpy terrain This bike ships ready to be assembled, and the wheels measure 29 inches