Just completed a Dax FD on a Schwinn Riverside Ladies bicycle and compared it to my Schwinn Riverside male bicycle powered by a Tanaka Purefire 2 stroke, 33cc engine with a light 5:1 gearbox and double right-sided chain drive with 11t/54t sprockets. The Dax is powered by a Robin EHO 35 and a 1 inch roller, which produces good low end torque and about 26 mph top speed, a perfect combination. The Dax parts are very sturdy, includes all the hardware and is packaged well. We replaced the supplied 1.25 inch roller with the 1 inch roller, using a puller, per the new Dax video. The Robin has thru holes, so we used 1.75 inch mounting bolts rather than studs supplied in the kit. Both bikes tested well. Both are quiet, the Robin a little louder. It's easier to gearup the chain drive using a 14t drive sprocket than it is to change rollers on the Dax FD. Both bikes tested about the same, with the only difference being how the engines perform. The Tanaka wants to almost shift to a higher rpm power range for more torque, and after that it reach a fast, very smooth rpm range. It's very quiet for a 2 stroke. The Robin has better low end torque but both engines produces good top end speed. Both engines are exceptional. The advantage of the Dax FD is it installs quickly, almost on any bike, and the advantage of the chain drive is very durable, all weather performance, although the DAX FD can ride in snow and wet weather. The throttles/kill switch is from DAX, a very nice combo after grinding off the inner plastic stub for tighter mounting.