Bicycle rollers are a type of bicycle trainer that make it possible to ride a bicycle indoors without moving forward. However, unlike other types of bicycle trainers, rollers do not attach to the bicycle frame, and the rider must maintain balance on the rollers while training. Bicycle rollers normally consist of three cylinders, drums, or "rollers" (two for the rear wheel and one for the front), on top of which the bicycle rides. A belt connects the middle roller to the front roller, causing the front wheel of the bicycle to spin when the bicycle is pedaled. The spacing of bicycle rollers can usually be adjusted to match the bicycle's wheelbase. Generally, the front roller is adjusted to be slightly ahead of the hub of the front wheel. History Bicycle rollers are nearly as old as the bicycle itself. Mile-a-minute Murphy is pictured riding on them as early as 1901. Riding on rollers Balancing the bicycle without riding off the rollers is an extra challenge for the rider and requires much more balance and attention than bicycle trainers. Some cyclists find that this increased attention to balance enhances their workout, while other cyclists simply prefer the more stable trainers. Rollers are also used by bicycle racers to finely tune their balance, a skill needed for drafting and the close quarters of a peloton during races. Novice cyclists often start by placing the bicycle rollers in a hallway or door frame where there is a nearby wall for support in the case of a fall. Removing any sharp and dangerous objects from the area is a must and a helmet is often worn, even though the user might be indoors. Beginners quickly discover that it is easier to maintain one's balance by focusing on a point a few yards ahead rather than looking directly down at the front wheel. In addition, it is easier to stay on the rollers in a higher gear when the wheels are spinning faster. Also, the user has no forward momentum while on bicycle rollers, which drastically reduces the possibility of injury in the event of a loss of balance or a fall. Construction Rollers The rollers themselves may be made from wood, aluminum alloy, or plastic. Aluminum alloy is usually a better choice because plastic rollers tend to bend and become misshapen from their regular cylindrical shape after use. Some rollers also have a concave