Agreed. 72W seems inadequate.

 

You could use that motor to drive the chain that drives the free-wheel, that would solve the non-back-drive problem, but what I do not see is a motor output shaft. I am guessing, based on the appearance, that it is a power seat adjusting motor. If that is the case then it does not have an output shaft, it has a square hole to drive a flexible shaft. So let us know what the original application was.

Yes, you're right, a square hole to drive a shaft.

 

The solution is to drive a sprocket that engages the pedal chain thru an over-running clutch, and use one of the flexible drive cables as the connection. That will allow a very minimum drag and also eliminate the problem of the motor stopping the wheel.
But there is one additional concern, which is that motors for any of the adjustment accessories in a car are intended for intermittent duty applications and they will get way to hot in anything like constant duty service, especially at anything near full load. Of course, the guess about the original application is still just my guess.

 

The solution is to drive a sprocket that engages the pedal chain thru an over-running clutch, and use one of the flexible drive cables as the connection. That will allow a very minimum drag and also eliminate the problem of the motor stopping the wheel.
But there is one additional concern, which is that motors for any of the adjustment accessories in a car are intended for intermittent duty applications and they will get way to hot in anything like constant duty service, especially at anything near full load. Of course, the guess about the original application is still just my guess.

I did manage to get some specs: It is 12 V, 2.8A , 590 RPM No load and it is a car seat motor

 

Cae seat motors are able to provide quite a bit of torque, but consider how long the average car seat adjuster motor is run, even when one is trying to get exactly the right position. Those are short duty-cycle motors and if you run one for five minutes it will probably get "quite warm." Also, at 12 volts and 2.8 amps it is about a 32 watt motor, which may not provide enough torque to be worth the effort.

 

Cae seat motors are able to provide quite a bit of torque, but consider how long the average car seat adjuster motor is run, even when one is trying to get exactly the right position. Those are short duty-cycle motors and if you run one for five minutes it will probably get "quite warm." Also, at 12 volts and 2.8 amps it is about a 32 watt motor, which may not provide enough torque to be worth the effort.

No, 2.8 A is the No load current not F.L. which I guess is @10A