Sorry that I didn't post to the forum, but what I said was there are timing belt (positive drives) available today that can replace some chain and vee-belt drives. Even some of the motorcycle brands are using them on their primaty and secondary (high torque) drives, hence replacing the chain drive. Some of these belts are reinforced with Kevlar cords which make them extremely strong. In some cases, you may be able to use a smaller diameter pulley to achieve a more desired ratio. They are a positive drive as long as you stay within the design parameters. They run quiet and smooth as well, and require zero lubrication. The one diadvantage is they are not self cleaning around dirt and mud, like a chain and sproket would be.Thanks for letting me opine. Others may disagree, but I'm talking from 45 years of industrial experience. Good luck on your project.