The belt in many CVT units can be a large duty “V-belt” and that is V-shaped in cross part. They are fabricated from rubber factors reinforced with Kevlar and various resources to reinforce toughness. That's why this stuff has to be pretty robust in building, generally causing major parts. https://gearbox-cvt31852.blog5star.com/32791928/the-greatest-guide-to-gearbox-cvt