There was no gearbox and variation in transmission ratios was provided for by variable pulleys.

A large number of transmission ratios means the driver can operate the engine more efficiently.

The higher cogwheel drive and the lower cogwheel are coupled via an intermediate gear with a transmission ratio of 1:2.43.

The secret is a metal link-plate chain working between two split pulleys, which, as they move together or apart, change the transmission ratios.

The gear assembly also provides required transmission ratio so that it can generate necessary force to move switch blades.

There were minor revisions to the transmission internal ratios as well.

As the positions of the rollers change, so does the transmission ratio.

Compound planetary gears can easily achieve larger transmission ratio with equal or smaller volume.

They must have reached the top of the track, because I heard revving and the transmission ratios change, then the noise disappeared completely.