I have a 2012(?) Ish Trek Mamba GFE Disc that is no longer my main bike and I've decided I want to use it to build a gas mobike build. I know I want four stroke, still deciding on which motor to use so suggestions are welcome. Anyway, I figured I'd do more of a DIY kit than just buy one. I have this idea to use a centrifugal clutch and attach it to a NuVinci roller CVT to have more control over speed ratio. The only thing is, I don't want to slap a second chain on. I'd rather connect the power to the main chain (which I understand i'd ikely have to upgrade the chain and probably take the derailleur off, etc) to meet it simple and be able to leave the rear disc on. I know there are kits for that, I just forget what they're called, but I know they are design to attach power to the front main chain sprocket / hub. Can anyone redirect me towards some of these kits or remind me of what they are called? I forget and I can't seem to find the right product via Google search (damn my goldfish memory). Any and all help / suggestions is much appreciated! I'd love to get more detailed info on motorized bike conversions!