And over here our streets have ascents, Lowlander
I'm from Germany by the way and here the e-bike/pedelec market is booming. Bosch builds a mid mounted electric motor now and they are completely new in this field. There seems to be a lot of market potential.
So in this respect a system that could give any old bike some tailwind with almost no modification is certainly a good idea. I just wonder if it safe enough.
Not sure if this is true for situations where you'd be able to catch it. Maybe it's the same for all bike trailers with this sort of hitch. I've never been riding with a normal trailer. But they seem to save. It's hard to imagine what's worse: unbreaked mass or unbreaked mass with electric motor support. On a lever flexibly connected to your tail.
Anyways, i've a new project now: i'll add an electric motor to my front wheel. I won the auction for an cheap e-bike at ebay. I'll slaughter off the electric components and re-sell the rest as trekking bike. It has a 36 V, 250 Watt motor, a Li-NiCoMn 11 Ah accu, speedsensor, controller and a charger.
And on top of that i ordered a NuVinci N360 in the US. That's a speedhub with continuously variable transmission. It has a really interesting technical approach without cogwheels.