Yeah, I wanted to do something like that for years since aftermarket brushless hubs were offered for bikes. I was going to retrofit a manual wheelchair with them and use a lithion batttery pack to power it.
Zapbike use to have 3 scooters when they started up. One looked like a beefy skate board with a 6 inch wide rear tire. It used 36 volts and claimed 0-35mph in 2 seconds. I imagines it you werent prepared it would shoot right out from under you. I think it even came with a wheelie bar too.
Since, many more scooters have come to market and are avaliable in any store from target, pepboys, kmart, etc.
Heck, I have an old 4 pole brushed wheelchair motor with 10 inch tire that will go 7mph at 24 volts. I was going to put a larger wheel and tire on it with a humb adapter from some robot motor website and make a trike attachment for my wheelchair. That was after I ran out of money from my other wheelchair and low vision modifications.