Kinetic Z-Rollers are the perfect option for developing better balance and technique or for pre-race warm-up. Precision machined aluminum rollers and premium bearings provide a smooth, quiet ride. A lightweight aluminum frame folds down for easy transport and storage. Z-Rollers are adjustable to fit bikes with a wheelbase from 38.2 to 43.3 inches (97cm to 110cm). Kinetic backs it up with the cycling industry’s best warranty.