2 spd jack shaft doesn't look right

[d2willys]

ok guys why is a double sprocket clutch necessary to make this work? the way i envision it any clutch even a tav could work. is it simply added stress requires a stronger connection?

The way I see it is that the double sprocket clutch could easily be a single sprocket clutch with a regular sprocket keyed right to the crankshaft. This would mean that the jack shaft clutch bell will be turning with the engine, but the jackshaft does not start to turn till the engine clutch engages. Once the jack shaft comes up to shift speed, it then engages the jack shaft to the engine and allows the 1st gear sprag clutch to disengage.

Am I correct in this assumption?:hammer:

 

[OFLHLG]

the gear on the outsdside with the heavy hub has (or should have) special needle bearings that act as a one way sprag...it will drive off of that until the clutch next to it reaches speed at which point it engages and overtakes the sprag causing it to disenagage and drive off the smaller sprocket on the clutch.....no???

I still don’t understand why the one way bearing is needed. The only thing I see that it does for you is allows you to manually back the bike up without all the other gears and chains turning. When the engine is driving that shit is never going to try to spin backwards I don’t get it. Everything turns in a counterclockwise motion while being driven by tge engine…

 

[ruppking]

The sprocket with the one way bearing is your 1st gear. When the RPMs on the jackshaft reach a certain speed the secondary clutch on the jackshaft engages and because of the sprocket size on this clutch it overrides the 1st gear sprocket to give you your 2nd speed. One or the other has to freewheel when the other is engaged.

 

[Skipp]

https://www.parduebrothers.com/minibike/twospeedthreechainminibiketransmission.pdf