Confusion on JackShaft kits

[bike4life]

OK. So basically, i think you have a freewheel that is somehow attached to the axle thing that connects to the pedals, does it just plop on the existing one or do you need to replace that? Then I believe you have to bolt on a gear set to the freewheel, and one of the gears accepts the chain from the jack-shaft and another one leads to the rear wheel.

So basically here is my question: If the engine is running up a hill and you pedal along to help it, wouldn't that create a major issue b/c the engine wants to rotate the gears at 5000rpm while your foot pedals want to rotate the gears at 60rpm ????? I assume you start the engine by pedaling like normal and you don't need an electric start or something.

 

[mark20]

to answer your question,
no the jack-shaft kit gives you a crank-set that basically is another freewheel,
if the engine is spinning faster than your feet are to the cranks then it wont help the engine.
its like if you shift to the lowest gear on a bike then go downhill and try to pedal,
you wont do anything as the rear wheel is faster than your legs moving the cranks,
hopefully this answers your question.

 

[bike4life]

to answer your question,
no the jack-shaft kit gives you a crank-set that basically is another freewheel,
if the engine is spinning faster than your feet are to the cranks then it wont help the engine.
its like if you shift to the lowest gear on a bike then go downhill and try to pedal,
you wont do anything as the rear wheel is faster than your legs moving the cranks,
hopefully this answers your question.

SOOOO IF I used the crank set that came with the bike, (as i am not going to buy a kit, just DIY it) would that be a problem?? I dont think the ones in the kit are really any different I'd assume.

 

[mark20]

SOOOO IF I used the crank set that came with the bike, (as i am not going to buy a kit, just DIY it) would that be a problem?? I dont think the ones in the kit are really any different I'd assume.

Well, if you use the stock ones, then your basically fixed to the engine, (ie if you start the engine your cranks will turn the same amount. So everytime you turn on the engine you have to keep pedaling, if you stop your engine will stall out, it's like a fixed gear bike, once you start pedding you have to keep peddling.

 

[bike4life]

Well, if you use the stock ones, then your basically fixed to the engine, (ie if you start the engine your cranks will turn the same amount. So everytime you turn on the engine you have to keep pedaling, if you stop your engine will stall out, it's like a fixed gear bike, once you start pedding you have to keep peddling.

How will it stall out?? The freewheel won’t engage the sprockets? So I guess u r saying the kit cranks have an additional freewheel that the stock ones don’t have?

 

[mark20]

How will it stall out?? The freewheel won’t engage the sprockets? So I guess u r saying the kit cranks have an additional freewheel that the stock ones don’t have?

Yes, that's exactly what I'm trying to say.

 

[bike4life]

Yes, that's exactly what I'm trying to say.

Ok. So if I get one of these things http://sickbikeparts.com/bottom-bracket-cartridge-206mm/, the engine won’t stall out?

 

[mark20]

Ok. So if I get one of these things http://sickbikeparts.com/bottom-bracket-cartridge-206mm/, the engine won’t stall out?

No, that's the bottom bracket (bb) you need the crankset, (the part that connects to the pedals) look at the picture with the big sprocket, see that brass part in the middle, that's the additional freewheel you need for a shift kit to work. https://www.ebay.com/itm/263540866649

 

[bike4life]

No, that's the bottom bracket (bb) you need the crankset, (the part that connects to the pedals) look at the picture with the big sprocket, see that brass part in the middle, that's the additional freewheel you need for a shift kit to work. https://www.ebay.com/itm/263540866649

Ok. I just need 1 freewheel, the gold one. When you said additional, the first one you were refferring too was the one in the rear tire b/c for a second i thought the jackshaft kit came with 2 freewheels.

 

[mark20]

Ok. I just need 1 freewheel, the gold one. When you said additional, the first one you were refferring too was the one in the rear tire b/c for a second i thought the jackshaft kit came with 2 freewheels.

Yes, you just need the one that connects with the cranks, the jackshaft kit only comes with one.