The CycleOps Rollers use lathe-turned rollers with precision bearings. The belt is adjustable for right or left dismount. Adjustable to fit any size bike. Resistance unit works on aluminum rollers. 68 decibels @ 36" 20 mph. Belt is adjustable for right or left dismount. Extra-wide bi-fold design is stable yet stores easily comes fully assembled. Adjustable to fit any size bike. Lathe-turned 3.5" rollers on the PVC version and 3.25" on the aluminum.