RPM
The 1000 RPM would be at the spooler, not the flywheel. How are they connected? What are their respective diameters?
I’m assuming you currently use the foot pedal. That has to limit the flywheel to about 120 RPM. With a 6:1 belt drive ratio you would want 720 RPM from the motor. Now you need to calculate the torque need to accelerate the wheel from 0 to 120 RPM. What does the flywheel weigh?
This type of assembly is not going to stop quickly. Does the flywheel continue to rotate after you stop pedaling?