Read enough by wesnewell about YESCOM's 48V, 1000w kit that it seemed appropriate to try one. Finally got around to mounting it on a Tidal Force frame that was laying around doing nothing and coupled it with a Luna Cycle 52V, 10 ah battery. Assembly was easy with the only glitches revolving around mounting the battery since the frame's triangle wasn't adequate with the controller mounted there. Ended up strapping it on a front rack. Anyway, couldn't be happier with the conversion; speed must be close to 30 mph; 170 pound rider, flat road, no wind; 50 - 60 pound bike (no speedometer yet). So for $250 (kit) and $350 (battery), you can make a pretty nice conversion to an existing donor bike. My photographer is ill, but pictures when she recovers.