Engineering a notched belt is certainly a balancing act among versatility, tensile cord support, and tension distribution. Precisely formed and 
spaced V Belt 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 substances, cover materials, construction methods, tensile cord advancements, and cross-section profiles have resulted in an often confusing array of V-belts that are extremely application specific and deliver vastly different levels of performance.
Unlike flat belts, which rely solely on friction and may track and slide off pulleys, V-belts possess sidewalls that fit into corresponding sheave grooves, providing additional surface area and greater balance. As belts operate, belt stress applies a wedging pressure perpendicular to 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 in to the groove of the sheave while operating 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 varied types may cover the share material to supply a layer of protection and reinforcement.
V-belts are manufactured in a variety of industry regular 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 several sizes (A, B, C, D, Electronic) and lengths, and are widely used to replace V-belts in older, existing applications.
They are accustomed to replace belts on industrial machinery manufactured in other parts of the world.
All the V-belt types noted above are typically available from producers in “notched” or “cogged” variations. Notches reduce bending tension, enabling the belt to wrap more easily around small diameter pulleys and permitting better heat dissipation. Excessive temperature is a major contributor to premature belt failing.
Wrapped belts have a higher level of resistance to oils and extreme temps. They can be utilized as friction clutches during set up.
Raw edge type v-belts are better, generate less heat, allow for smaller pulley diameters, increase power ratings, and provide longer life.
V-belts look like relatively benign and simple devices. Just measure the best width and circumference, discover another belt with the same sizes, and slap it on the drive. There’s only one problem: that strategy is about as wrong as you can get.