Full definition
V-belt whose rubber sidewalls are not wrapped in fabric, leaving the compound directly exposed to the pulley groove walls. This uncovered surface provides a higher friction coefficient (up to 30% more grip), better flexibility for smaller pulleys, improved heat dissipation, and higher power capacity than wrapped belts of the same profile. Available in cogged (notched) or smooth configurations. Standard in modern industrial drives. Per ISO 4184 and DIN 7753. Minimum pulley diameters 15-25% smaller than wrapped equivalents. Brands: Optibelt VB, Gates Hi-Power II, Continental CONTI-V. Expected life: 20,000-30,000 hours under proper conditions.