A carbon-fiber-reinforced belt from Gates Corp., Denver (www.carbondrivesystems.com), replaces the traditional chain usually found on most bicycles. The synchronous belt and its teeth are made of polyurethane, which resists weather and UV radiation, and survives temperatures from –65 to 185°F. Nylon fabric on the belt teeth adds durability and extends the belt’s life. Ribbing on the back of the belt reduces bending friction, And carbon-fiber tensile cords in the belt prevent it from stretching.

The chain-ring and rear-hub sprockets, both part of the drivetrain, are constructed of aircraft-grade aluminum for a high strength-to-weight ratio. The sprockets are also coated with an abrasion-resistant ceramic. Mud ports, slots directly under the teeth, let mud and debris escape as it sloughs off when the belt turns.

In all, a typical carbon drivetrain weighs 240 gm, roughly half the weight of conventional chain drives, but has the same efficiency. That efficiency lasts the life of the drive since it does not deform or wear over time nearly as much as traditional chain drives. Test show the new drive lasts three times longer than standard roller chain. The new drive also requires no lubrication.

Edited by Stephen J. Mraz