See your fitness-and your bike handling skills-improve when you add CycleOps rollers to your training program. You’ll increase your balance, control and ability to ride a straight line, all of which translate to more efficiency, power and technique on the road. And because you have to pedal 100% of the time to balance your bike, you get an amazing workout, whether you choose to go at an easy spin or a more intense pace. After a winter on rollers you’ll be poised to lead the pack in the spring.Precision-lathed 3.25″ aluminum roller drums run silent and smooth, and won’t distort in heat or sunlight. Fold flat or stand on end for convenient storage. Designed for both indoor and outdoor use.