Minimal speed control for 12v dc motor

Is there a simple way to adjust speed on a Cytron SPG-50-60K DC motor powered with a 12V battery pack? I want to minimize size and avoid electronics if possible. Could it be as simple as just a resistor or potentiometer? I’d appreciate any advice.

Many thanks!

bogehring

robotshop.com/en/cytron-12v- … motor.html
The rpm relates to the voltage. As you lower the voltage, the rpm will decrease.
Ref: robotshop.com/media/files/pd … cyt-36.pdf
However, that motor operates most efficiently at 12V, so if you try to operate it at 6V, the efficiency will drop a lot, which reduces the life span of the motor.
The best way is to use a DC motor controller or choose a lower RPM motor.
robotshop.com/en/brushed-mot … llers.html