Engineering a notched belt can be a balancing act among versatility, tensile cord support, and stress distribution. Precisely shaped and spaced notches help to evenly distribute tension forces as the belt bends, thereby helping to prevent undercord cracking and extending belt existence.

Like their synchronous belt cousins, V-belts have undergone tremendous technological development since their invention by John Gates in 1917. New synthetic rubber compounds, cover materials, construction strategies, tensile cord advancements, and cross-section profiles have led to an often confusing selection of V-belts that are extremely application specific and deliver vastly different levels of performance.
Unlike toned belts, which rely solely on friction and can track and slip off pulleys, V-belts have sidewalls that fit into corresponding sheave grooves, offering additional surface and greater balance. As belts operate, belt stress applies a wedging force perpendicular to their tops, pressing their sidewalls against the sides of the sheave grooves, which multiplies frictional forces that permit the drive to transmit higher loads. How a V-belt fits in to the groove of the sheave while working under stress impacts its performance.
V-belts are produced from rubber or synthetic rubber stocks, so they possess the versatility to bend around the sheaves in drive systems. Fabric materials of various types may cover the stock material to provide a layer of security and reinforcement.
V-belts are manufactured in a variety of industry standard cross-sections, or profiles
The classical V-belt profile goes back to industry standards created in the 1930s. Belts manufactured with this profile come in many sizes (A, B, C, D, E) and lengths, and so are widely used to displace V-belts in older, existing v belt china applications.
They are used to replace belts on industrial machinery manufactured in other areas of the world.
All of the V-belt types noted over are typically available from producers in “notched” or “cogged” versions. Notches reduce bending tension, enabling the belt to wrap easier around small diameter pulleys and enabling better warmth dissipation. Excessive heat is a major contributor to premature belt failure.

Wrapped belts have a higher level of resistance to oils and severe temperatures. They can be used as friction clutches during set up.
Raw edge type v-belts are better, generate less heat, allow for smaller pulley diameters, enhance power ratings, and provide longer life.
V-belts appear to be relatively benign and simple devices. Just measure the best width and circumference, find another belt with the same dimensions, and slap it on the drive. There’s only 1 problem: that approach is about as wrong as possible get.