Hub vs mid drive for very slow off-road trike

[ArgusMcJohnsten]

First off, I don't know if I'm even in the right area, or if I should be in the scooter area. I have a recumbent trike that I use as a mobility device at a day camp. I usually do walking speed of an elementary student, slow enough my speedometer doesn't even register sometimes, rarely ever go over 5mph and never more than 10mph.
My condition is getting worse, and I'm not able to pedal as far without fatigue, so I've been thinking about trying to electrify it somehow. I'm thinking with a throttle, and keep peaking as a backup so I don't get stuck in the woods somewhere when the battery dies. I'm thinking mid/external drive (not sure the proper name), or even salvaging a wheelchair motor would be the better choice, so I can take advantage of gearing. But I'm new to this and thought I'd ask advice on motor type and if what I'm wanting to do would even be possible.

Thanks

 

[Papa]

What format?

Tadpole (2 wheels front, 1 rear)?
Delta (1 wheel front, 2 rear)?
Manufacturer'?
Other?

 

[ArgusMcJohnsten]

I currently have an ICE adventure tadpole, but looking at adding a sun delta as well

 

[offGridDownUnder]

Grin sells a 30:1 reduction hub motor for use in wheelbarrows - you would need to mount a tire or use a belt on it to drive another wheel - I have not at all considered how feasible this is.

My trike design uses a hub motor as a mid-drive/stoke-monkey motor behind the seat to the rear wheel connected by a Gates Carbon belt - I can change the ratio between the motor and wheel this way. I'm currently using 26T on the motor to 48T on the wheel to trade speed for power on hills or with loads. This sounds like what you might want, and a 20:70 reduction ratio at least is possible. It does require building a motor mount for behind the seat, and I don't know if that fits with the trikes you are considering. I am using a Greenspeed Magnum Big Wheel - but several of the Greenspeeds should be possible.

I am currently designing a better motor mount and will make the design available for others. I have used a GMAC for the motor, I'm currently mounting an SX2, and I'm designing the motor mount to use a Grin All-Axle v3 rear motor with torque sensing - but you could put a torque sensor on the pedals with any motor.

You can see some pictures of my design in the third listed bike in my signature - scroll down for a later picture with the Gates Carbon belt.

You can do this with any frame that provided a space to put the motor somewhere on the way from the pedals in the front to the driven wheel in the rear.