about 8 years on mine with over 320 on the seat. Chain was like the day we installed it. You just have to know how to properly fit the chain to your Cam to crank spread. That is why they make special order sprockets in different sizes. A loose chain will just get looser from stretch. A tight chain will gull and wear faster. Guys that don't know how to do this . Just throw a power robbing gear drive on it.