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

Like their synchronous belt cousins, V-belts have undergone tremendous technological development since their invention by John Gates in 1917. New synthetic rubber substances, cover materials, construction methods, tensile cord advancements, and cross-section profiles have led to an often confusing selection of V-belts that are extremely application particular and deliver vastly different degrees of performance.
Unlike flat belts, which rely solely on friction and may track and slide off pulleys, V-belts possess sidewalls that match corresponding sheave grooves, offering additional surface area and greater balance. As belts operate, belt tension applies a wedging push perpendicular with their tops, pressing their sidewalls against the sides of the sheave grooves, which multiplies frictional forces that allow the drive to transmit higher loads. How a V-belt fits into the groove of the sheave while operating under tension impacts its performance.
V-belts are made from rubber or synthetic rubber V Belt stocks, so they have the versatility to bend around the sheaves in drive systems. Fabric materials of various types may cover the share material to supply a layer of protection and reinforcement.
V-belts are manufactured in various industry standard cross-sections, or profiles
The classical V-belt profile dates back to industry standards created in the 1930s. Belts produced with this profile can be found in a number of sizes (A, B, C, D, E) and lengths, and are widely used to displace V-belts in older, existing applications.
They are used to replace belts on industrial machinery manufactured in other areas of the world.
All of the V-belt types noted above are typically available from producers in “notched” or “cogged” versions. Notches reduce bending tension, enabling the belt to wrap more easily around little diameter pulleys and allowing better high temperature dissipation. Excessive heat is a significant contributor to premature belt failure.

Wrapped belts have an increased level of resistance to oils and severe temperature ranges. They can be used as friction clutches during set up.
Raw edge type v-belts are better, generate less heat, enable smaller pulley diameters, boost power ratings, and provide longer life.
V-belts look like relatively benign and simple devices. Just measure the top width and circumference, find another belt with the same sizes, and slap it on the drive. There’s only 1 problem: that strategy is about as wrong as possible get.