Hi my name is Norman . We currently have 2 Bionx 500watt kits on Giant mountain bikes and also have 3 Velec R48's . Currently my daughter and I commute to work 8 miles one way (16 total) . My bike is a 2 year old Velec with 10000 miles on it . My wifes has 4500 miles and is 1 year old . Just bought the 3rd Velec R48 7 days ago and have 120 miles on that one . The Bionx kits have a combined milage of 15000 miles and are 2 and three years old . I am on this forum to learn about electric bikes and try to figure out what to buy next . Also am always trying to improve ours .