Pro form 225 csx upright bike the pro form 225 csx upright bike is designed and built with a digital silent magnetic resistance from 1 20 an inertia enhanced flywheel and a freewheel clutch to keep the motion of the bike consistent at all times giving the feel of a real road bike the new 225 csx upright bike is perfect for your at home cardio training allow the ekg grip pulse feature to retrieve accurate pulse readings on the go while you work through one or more of the 20 pre set workout