Electric Cargo Bike build: Need advice

[BartRidesEternal]

Hi guys,

So I got an opportunity to build an electric cargobike to haul stuff and people around.
It will be an "Two Wheel" cargo bike like this (picture from the interwebs):

I was wondering about the options regarding electrical motors:

1. Front wheel motor
2. Rear wheel motor
3. Central (bottom bracket) motor

My first thoughts and things I read on the internet:

Front wheel:

• A front wheel motor could skid when riding away without a load.
• A front wheel motor has a long wiring harness and the wiring is moving due to a steering movement.
• With a dead battery you can still cycle in comparison to a central motor.
• You can still have a rear hub with gears.
• A bit more weight on the front.
• Centre of gravity relatively low (20" front wheel).
• Front disc brake possible.
• Also rollerbrakes are available, but I really dislike these rattling brakes.
• More force on the front fork.

Rear wheel:

• Rear cassette or derailleur, no internally geared hub.
• A bit more weight to the back.
• With a dead battery you can still cycle in comparison to a central motor.
• Centre of gravity a bit higher compared to a front wheel motor (24+ or 26 inch rear wheel).
• Disc brakes possible.

Central, mid-motor: (mounted on a standard BSA bottom bracket)

• Low centre of gravity.
• Looks good.
• Due to a long bike that needs to be practical: Motor too low? It hangs underneath the bottom bracket.
• Assembly strong enough?
• Replacement sprockets standard??
• Internal gear hub still possible.

Does anyone have something to add and experiences to share?
Normally I don't ride and/or build electric bikes, so I need to do some research and try things out.

Thank you in advance!!

 

[Da Gas Man]

I don't know anything about electric bikes either and I like the design of that "work bike"
in the photo. But it seems to me that without two wheels up front, the load in the bucket
would need to be very centered and stable to prevent pulling to one side or tipping over.
There might have to be a weight limit for the load? 200+ pound person may be difficult
to steer about. Good luck with the build. I am fascinated by the concept.