The kurt kinetic z rollers are the perfect option if you are a developing rider that wants to improve their balance and technique or for a pre race warm up precision machined aluminium rollers and premium bearings provide a smooth quiet ride a lightweight aluminium frame folds down for easy transport and storage zrollers are adjustable to fit bikes with a wheelbase from 382 to 433 inches 97cm to 110cm kinetic backs it up with our unconditional lifetime warranty click on the video link