Jackshafts? Please Help!

The jackshaft will allow you to use your existing gears.

Here is a photos back in 2009 when Roland (original owner of Spooky Tooth) was trying out the jack shaft for the first time. He ended up blowing up his 3 speed hub.

Photo was taken at Death Race, where run what you brung was the name of the game and a few beers made the racing better lol.

most folks think you lose about 2mph off your top speed with these, but get much better speed up hills - typically, though, they cost more than the whole rest of the kit and a used bike put together

I need to find out what brand of bike frame the shift kit pedal shaft bearings will fit?? I have an OLD, OLD 10 spd. mountain bike out in the shed that I was gonna put an engine kit on, but then I saw those shift kits on YOUTUBE and that's the way I wanna go. I built about the same thing with an old 33cc weedeater motor a bunch of years ago and it worked good except that it didn't have the freewheel in the crank sprocket, so I had to make footpegs to get my feet off of the pedals when it got going. It worked great and shifted great and went pretty good for only 33cc's but that deal with hanging my feet out behind me kinda sucked. I had to do that because the motor drove my pedals and there wasn't any way my feets could keep up!