Bicycle rollers are a type of treadmill for a bicycle, consisting of a frame housing a set of three cylindrical rollers. Two rollers at the rear contact the back wheel of the bike, while the front wheel rests on a single roller. A band connects the two front rollers, allowing the front wheel of the bike to turn as the cyclist pedals, while the rear roller spins freely.
Bicycle rollers allow cyclists to practice balance as well as speed and endurance, because the bicycle is not directly attached to the frame in any way. Balancing on static rollers is much more difficult, especially at the beginning of the workout. For this reason, cyclists usually place rollers near a wall or door frame so that they have support until the wheel speeds become sufficient to aid in balancing the bike. For cyclists who dislike the extra balancing effort required, there are trainers that attach to the rear wheel and raise it off the ground, steadying the bicycle in place. These require users to connect the device with tools, however, and take some time to set up properly.
Bicycle rollers have been around almost as long as bicycles, with early versions of the device dating back as far as 1901.