The S2 is a mid level indoor cycling bike from the LifeSpan Fitness line. It features a 40 pound flywheel, a heavy-gauge steel frame, and a poly-v belt drive system. The seat and handlebars are adjustable vertically and horizontally. The pedals and seat can be swapped out for others. The resistance is adjusted with the turn of a knob, which is located just above the flywheel. The maximum user weight is 300 lbs. The S2 is backed by a 5 year warranty on the frame, 1 year for parts and labor. Dimensions: 44 x 22 x 22 inches ; 97 lbs.
The LifeSpan S4 is a gym quality indoor cycling bike that features a 44 pound flywheel, a Poly-V belt drive, and fully adjustable handlebars and seat. Also included is a leather resistance knob with a push brake, and alloy pedals with sealed bearings. The maximum user weight is 400 pounds. The dimensions are: 48 x 48 x 26 inches (W x H x D). LifeSpan backs the S4 with a 5 year warranty on the frame and 2 on the parts.