Gearing is the way we translate RPM into the torque required for a given task a motor that spins at a given torque at a given RPM can be made to do more work with gears. This is the basis for the concept of transmission & chain rings or pulleys are among the simplest ways to accomplish the transmission of the RPM desired at the torque needed.
I'm still working with the idea of a 1Kw motor mostly because motors are rated far below their actual capacities & this is one of the stronger scooter motors on the market. Motors are generally rated as their continuous capacity while their peak capacities are often 3-4 times higher & the only serious concern is burnout which can be combated with a cooling system. So while the motor in question is rated at 1kw it can actually produce as much as 5 Horsepower under peak conditions for relatively short periods of time. There's still the debate as to whether or not it could move forward from a stop while pointed up a 25% grade. I have however come up with a way to overcome my RPM incongruency. A vertical stack of gears. From the motor sprocket we get 11 teeth spinning at up to 3000 RPM if we goto a 36 tooth sprocket married with a 9 tooth sprocket we reduce our RPM from the motor to that ring from 3000 to 917RPM & then from our 9 tooth transmission gear to the 20 tooth drive sprocket on our axle we get a spin of about 412 RPM unburdened wheel speed & an estimation of about 25 mph at 360RPM the expected burdened rotation. The only question left is if this gearing can get the job done in less than ideal conditions.
Beyond this I'm looking at electric go-kart motors & golf cart motors. I've just about given up on hub motors as either prohibitively expensive for this project or under-powered for a bike where I intend to remove the pedal assist.