All Cateye Ergocisers feature the best magnetic and electromagnetic resistance system in the industry -- The Eddy Current Workload Modulation System. So you can count on years and years of smooth, quiet, trouble-free training time. With no alternators, friction pads pr physical contact with the breaking surfaces to worry about, your Cateye bike is virtually maintenance-free. Still, it's nice to know every model comes with a 3-year limited warranty for commercial and home use.