Performance Roller Weights size 23×18 for 250cc water-cooled 172mm engines. Commonly found on 250cc water-cooled Chinese scooters, CFMoto V3 and V5 motorcycles and much more. We recommend starting performance upgrades by changing the variator roller weights first. Heavier roller weights= A slower take off speed with more acceleration and a higher top speed. Lighter roller weights = A faster take off speed with less acceleration and lower top speed. Please see our Warranty & Returns Policy.