bottom bracket jackshaft

[Toby woodman]

I'm wondering if anyone has any thoughts on this. having had two jackshaft fail either due to a bad design or just having too much play and flex in the whole setup, I'm thinking about doing this. because using a 160cc engine that's geared for 24mph won't require pedalling. i'm thinking about taking the cranks off and using the pedal spindle as a jackshaft. this would require me to turn the rear wheel around in the frame and use a standard 36tooth sprocket on the rear. if the bottom bracket bearings ever fail I will press in either standard sealed bearings or I would add some pillow block bearings around the bottom bracket and use a standard jackshaft. I will add some pictures. does anyone have any thoughts on this.

 

[GW's Motorized]

I've considered doing the same thing. If I were you I'd toss the cage bearings and press in seald bearings andnuse a 3/4 to 1 inch shaft for durability.

 

[Toby woodman]

Okay, it’s all about finding some sealed bearings that fit in the bb shell

 

[Chainlube]

Instead of running the power through your BB, just put a small sprocket on the other end of the jack shaft, right side, and then a chain back to the wheel. Take the pedals off and use a rod or pipe for foot pegs.

Chain from the engine to the jack shaft and then a chain from the jack shaft back to wheel. Two chains instead of 3 or 4.