MOTORS
The motors supplied with the Mechathlete kit turns at 3000 revolutions per minute (RPM) when connected to a 6 volt battery. When a motor is made to do some work, such as turning the wheels of a buggy, it slows down and takes more energy from the battery. If you try to make the motor do too much work, it stops and gets very hot. This is called stalling. A motor works best (most efficiently) when it is running at high speed. However, it does not have much "turning power" or torque. You can easily slow down a small motor by pinching the spindle between your fingers.
You can use a pulley or gears to give higher torque but slower speed. In a portable drill, a gearbox connects the motor to the chuck. In your Mechathlete, a pair of pulleys can be used to connect the motor to the axle. In these examples, the motor turns rapidly and the chuck or axle more slowly - but with higher torque.
