This 21-speed bike's dual suspension steel frame is built to withstand all the ruts on the trail and street speed bumps alike. It is fully equipped with Monk Reflex Technology features throughout the frame making this a work horse on the trails and a very secure ride on busy city streets. You can trust that the Reflex Technology will make you visible to all drivers on the road. The strong alloy rims support 26-inch knobby mountain tires suitable for all-terrain riding.