I have come to learn that the RadRunner does not really have a 750w motor, but a smaller 500 which may peak at 750w. Several online videos showing this, and it becomes obvious when you compare them side by side. So I purchased a new Bafang 750 hub motor, and am mounting it on my RadRunner. I am unable to get the chain to line up with the single gear threaded to the hub motor (which I transferred from the old motor to the new one), and with the front gear and the tensioner, even if I use spacers on the gear. The new motor came with a 7 gear cassette, so I installed that on the motor, and am able to get the chain lined up perfectly on the 3rd gear on the cassette. It pedals OK, and looks a bit silly, but works just fine. Has anyone found a way to install a true 750 motor in a RadRunner using just a single gear? By the way, I have installed a suspension front end, handlebar risers, a pan style sprung seat, 35a controller, color display, and a handfull of other accessories. I also installed 3 2000w LED headlamps, wired directly to the battery, for amazing night rides on the beach or golf course!