So far so good, my first working proof of concept works great mechanically under power.
This new base is designed for the 49cc HS 142F 4-stroke engine and NEW Grubee 4G belt drive transfer case to use it as a direct drive or a jackshafted shifter.
The new 4G case fully encloses the clutch and has the freewheel bearing on the big pulley and not the output sprocket so as a bonus it pedals with the engine off with virtually no gas power JS drive train drag through all the gears like the normal pedal bike except for the added weight of course.
The new 4G however is an inch wider so no jackshaft base matched it so I made my own.
The important things to note with my right bearing support is it has a second vertical support that pulls it in, and the bearing collar is on the inside with a shaft collar against it to keep the coupling together and the bearing in place and it gets rid of the 2 left side sprockets and chain, and hence their 'move the motor' adjustment.
That was the easy part, the hard part was accounting for the output so close to the engine on the right side and not have to try and raise the whole mount to tighten it.
The trick was my base accounting for a small adjustable tensioner sprocket (plastic gear with steel bearing mount) to route the chain and account for any chain 'stretch' that needs doing so in essence once the engine mount is in place that is the only adjustment to deal with and it's easy to do.
As suspected the .7 gear reduction I lost going with a direct shaft to the right side with every other ratio the same makes it a bit of a dog off the line but I have a 90T freewheel on its way to make it just a .2 loss and which means a .2 overdrive gain on the 38 MPH original gearing and the pedaling still matches the engine RPM better.
More later but we already have the covers on and pretty confident we can put the right side chain guard on with a couple of snips as well ;-}
This new base is designed for the 49cc HS 142F 4-stroke engine and NEW Grubee 4G belt drive transfer case to use it as a direct drive or a jackshafted shifter.
The new 4G case fully encloses the clutch and has the freewheel bearing on the big pulley and not the output sprocket so as a bonus it pedals with the engine off with virtually no gas power JS drive train drag through all the gears like the normal pedal bike except for the added weight of course.
The new 4G however is an inch wider so no jackshaft base matched it so I made my own.
The important things to note with my right bearing support is it has a second vertical support that pulls it in, and the bearing collar is on the inside with a shaft collar against it to keep the coupling together and the bearing in place and it gets rid of the 2 left side sprockets and chain, and hence their 'move the motor' adjustment.
That was the easy part, the hard part was accounting for the output so close to the engine on the right side and not have to try and raise the whole mount to tighten it.
The trick was my base accounting for a small adjustable tensioner sprocket (plastic gear with steel bearing mount) to route the chain and account for any chain 'stretch' that needs doing so in essence once the engine mount is in place that is the only adjustment to deal with and it's easy to do.
As suspected the .7 gear reduction I lost going with a direct shaft to the right side with every other ratio the same makes it a bit of a dog off the line but I have a 90T freewheel on its way to make it just a .2 loss and which means a .2 overdrive gain on the 38 MPH original gearing and the pedaling still matches the engine RPM better.
More later but we already have the covers on and pretty confident we can put the right side chain guard on with a couple of snips as well ;-}
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