teethThe efficiency of standard V belts will decrease over time from a peak of 95–98% to less than 93% due to ageing and failure to adjust the belt tension. Cogged belts have a greatly reduced bending resistance compared to standard V belts and can be used on the same pulleys as equivalent V belts. They also need less maintenance, run cooler, last longer and are around 2% more efficient than standard V belts.

Teeth belts are another alternative to standard V belts, i.e., they are more efficient and retain their efficiency for longer, but they may not be suitable for all applications due to noise and a low tolerance for shock loading.

Teeth belt drives have teeth on the belt and corresponding grooves on the pulley wheels. The meshing teeth provide positive angular location and hence there is normally no relative motion or slipping between the two elements in mesh giving a constant speed ratio between the driving and driven shafts. Teeth belts can therefore be used for applications such as automatic machinery where a definite motion sequence or indexing is necessary. A key consideration in belt selection and design is the material concerned and this topic remains an ongoing area of development.

The principal dimensions of a teeth belt drive are the number of grooves, the pitch and the width. The teeth belt pitch is the distance between two adjacent tooth centres measured on the pitch line of the belt. The teeth belt pitch length is the total length of the belt measured along the pitch line.