Before the advent of outrunners, most motors needed some form of reduction. Most used gearboxes, but if you needed to reduce the RPM by a factor of 2 or less, a belt drive became an option. Modelairtech, within the US, used to make beldrives. They had two designs, one limited to 500 watts of input power and another rated at 1000 watts. They are not as efficient as gear drives (it takes some energy to bend the belt around the pulleys), but they are quieter and provide some damping between the prop and motor. They maintenance is also simpler; no greasing.
The only significant limitation was that the RPM's at the pinion pulley could not exceed a certain level; otherwise, the belt came apart. I do not recall if the limit was 10K RPM or 15K RPM. In the day, the belt units worked best with the Mega or Jeti Phasor motors which had relatively low KV compared to other motors (800-1000).
Teo
PS. Ltc. Thank you for the price info. It seems reasonble given that what you get is the whole package.
Last edited by viva_peru; 11-25-2014 at 04:58 AM.