Worksman tricycle help please

[SimpleSimon]

When mounting rear drive on a trike one other thing to consider is what I call tire hop. One wheel is diven the other is not. When going into a sharp turn toward the drive wheel it will tend to hop or spin as its speed is reduced in the turn but the drive does not reduce it.

Agreed...but.

That issue is pretty straightfoward to deal with. Split the axle into two half-axles, and put a free wheel capable sprocket on the inboard end of each. Just forward of that mount a "mid-drive", which can be simply a jackshaft, or can be a muti-speed internally geared hub. In line with each of your inboard free wheel sprockets on the half-axles, mount sprockets on the mid-drive (jackshaft or hub, either one). This will allow power (either pedal or engine) to be transferred to each half-axle, but if the bike is rolling faster on one wheel than the other, as in cornering, the free wheel sprocket spins on the axle on that side. I call this a poor man's differential, as it in effect is a differential.

Lovely part is, if the mid-drive is a multi-speed hub, a primary jackshaft just forward of it can be used to combine both the pedal and power side inputs, giving you the full range of gearing either pedalling or under power. However, I would NOT reccomend you use a more tha 7 speed internally geared hub for this, as the more gears there are in a hub the tighter the internal tolerances become and the thinner each gear is made - strength of materials can become an issue. Not mainly because of engine torque, but rather because of transmitted vibration along the chain loop, which increase metal fatique and shortens hub life.

I know this works, as it is what I have - an HT engine driving a jackshaft to which the pedal crank loop runs, then the output of that goes to a Shimano 3 speed internally geared hub with ring sprockets mounted to the spoke flanges in line with free wheel capable sprockets on the inboard ends of the half axles.

One of these days I need to get a camera.

 

[Stan4d]

Agreed...but.

That issue is pretty straightfoward to deal with. Split the axle into two half-axles, and put a free wheel capable sprocket on the inboard end of each. Just forward of that mount a "mid-drive", which can be simply a jackshaft, or can be a muti-speed internally geared hub.

All sounds great....I am sure you have done it and have no doubt it works....but I think you left out one modification....the trikes I have come across have one freewheel in back and the hub needs to be fitted to the axel to achieve what you did. Again no doubt that you did it and it sounds like it will work perfectly. How did you modify the free wheel?
I ask because I have a schwin meridan trike I plan to convert sometime.

 

[Tanaka40]

So awesome passing the gas pumps at over 3 bucks a gallon in my area !!!! I love my GEBE setup. (my disabled son is even considering a Tanaka 32 cc on the front of his trike)

With a front wheel setup, you dont have to mess with the chain and just purchase the new front wheel with the ring installed. Installation time will be very minimal. Contact Dennise and Julia for more info.

 

[SimpleSimon]

All sounds great....I am sure you have done it and have no doubt it works....but I think you left out one modification....the trikes I have come across have one freewheel in back and the hub needs to be fitted to the axel to achieve what you did. Again no doubt that you did it and it sounds like it will work perfectly. How did you modify the free wheel?
I ask because I have a schwin meridan trike I plan to convert sometime.

Pretty simple. I loosened the axle clamps (which prevent it from moving sise to side), slid the axle out, sawed it in half and paid a machine shop to cut keyways in both ends of the left side half axle. Purchased two identical Sun Bikes freewheel sprockets, slid them on the axle inboard ends with stop collars, and there it was.

The output sprockets to fit the spoke flanges of the Shimano free wheel hub are fixed, and the pedal side and output sprockets of the forward jackshaft are fixed as well - the input sprocket to the jackshaft on the engine side is free wheeling when the engine is off. I have to pull start the engine, but that's not a big deal - although the quality of the pull starter I managed to get is abysmal, and I expect to need to replace it soon.