That’s interesting. I was gathering parts for a similar project myself a couple of years ago. That is powering the front wheel of a bicycle whilst leaving the rear end cycleable as usual. I was going to use a disc hub with a sprocket bolted onto it to give positive drive like that. I got myself a strimmer motor to use, but had figured I’d want a jack shaft to get the gearing about right.
I didn’t have the rest of the strimmer stuff left out front though.