The OEM crankshaft is internally balanced, there is no balancer attached to the crank pulley. All NST pulleys are perfectly balanced. Belt wear with NST pulleys is same if not better than OEM.Is the stock oem crank balanced? Is the NST balanced? Belt wear difference?
We have discussed harmonics and vibrations in great detail here... https://nonstoptuningusa.com/faq/
We also have real world reviews from real world NST customers in the Veloster community, pages and pages and pages of nothing but positive reviews...
Across platforms including Honda, Nissan, Toyota, Scion, Lexus, Infiniti, Acura, Hyundai, etc, our return rate for any item/reason is LESS than 1%.