Fantastic conversion kit! I have both Swytch 250w and Swytch 500w kits, which have converted my Treck DS 3 hybrid bikes. Riding is smooth and I can feel power constantly coming from the pedals. With 9 power levels of assistance to choose from, I can easily change my speed according to road conditions and traffic. At the highest level, the 250w motor can get you to a top speed of 20 miles per hour; the 500w motor can get a top speed of 28 miles per hour. I have chosen the 50-mile range battery. With noticeable assistance at level 4 or level 5, the battery can achieve around 40 miles in a complex city centre, where I have to stop and start endless times. Both bikes have done over 1000 miles without any problems. I thoroughly enjoy riding my Swytch-converted bike and would recommend it to anyone for its quality and good price! 5 Stars!