front chainring to jackshaft to 3 speed hub question!!

[gbginger]

ok guys i can not wrap my head around what sprocket i need to make my bicycle pedal. i need your help. so when i pedal now it feels like i have it in the lowest gear on a mountain bike. actually worse then that. i want to get a pedal start so i don't burn my clutch up because i want to run a 9:1 gear ratio on my biggs motor. i want to start this pedal in first gear on my hub. i can not change my rear sprocket. i can not change my jackshaft sprocket that goes to the rear hub… right now it goes from a 48 tooth from the crank to a 22 tooth freewheel and a 11 out to a rear 40. i want the pedal ratio of a regular beach cruiser and just don't know what direction to go with the tooth count on my sprocket.. any help would be great thanks..

 

[Chainreaction]

The only thing I can think of is finding a huge crank sprocket which will be hard to do. This is why I am using #35 chain, much more to choose from. You can easily get 100T sprockets AND with the smaller pitch they are smaller sprockets. That has it's own challenges though, you'd have to bolt or weld #35 hub to crank sprocket and change freewheel to #35 also.

 

[cannonball2]

If I am reading your sprocket sizes right you have an overall ratio(engine drive) which is about 17:1, that's really low for a Briggs. You will be slightly overdriven in 3rd(I assume a 3speed?) but that still not a very high overall ratio. Cant you run one of SBPs smaller adapters(5/8" keyed) and run a much smaller freewheel on the jackshaft to the pedal crank?

 

[gbginger]

yes.. i actually just picked up a 52 tooth crank and found a 13 tooth freewheel sprocket.. so this will help.. won't be 100 percent what i want but should be close. and it will just have to do. and the engine drive ratio should be 12:1 or close to it… i changed a sprocket around on my jackshaft to rear hub to a 12 tooth also to help give me a little more top end.. thanks

 

[BOYGOFAST]

What difference does it make ?, the 3 speed hub is not going to assist starting the engine unless locked sprocket in some manner once started you'll need to unlock it to employ the gear select.With a centrifugal clutch you will have to be superman to start that thing you need your head examined ..Move the drive sprocket to the opposite side of the hub or lock like I mentioned..

 

[gbginger]

I start my motor with a drill on my flywheel. Free wheel sprocket to my pedals from the jack shaft. Jack shaft to rear 3 speed Just trying to make it comfortable when I pedal the bike.