LISTEN and LEARN. EPI has been the industry leader in CVT Clutch tuning for over 20 years and we've made it our goal to educate enthusiasts like yourself about the importance of recalibrating your clutches when you add bigger tires or more power to your machine. As soon as you change to bigger/more aggressive tires or add more power to your machine, you need an EPI Clutch Kit to recalibrate your CVT system so your machine performs the way you expect it to.