Every time we receive new performance information about a new (or old) motor, we update the Slot Car News Motor List. The most recent update concerns our RPM test of the latest SCX motor, the Pro Speed.
The SCX motor is tested for no-load RPM at 12.00 volts, our standard. A black plastic disc, or "cookie", marked with reflective tape, is pressed on the end of the shaft, and the motor is run up to speed. We let it run at 12v for about five minutes to come up to operating temperature. The Checkline tachometer projects a red beam of light onto the disc, to ensure the tach is aimed correctly at its target.
Our reading averaged 19,414 RPM over a 30 second time span. The digital readout (above) shows a different number, because the RPM fluctuates at a constant voltage. All motors vary as they go. The tach itself averages the readings when given the appropriate command. This particular motor is brand new, and not quite broken in.
The Motor List is updated frequently. You can find the link, highlighted in yellow, by scrolling to the foot of this page.