practically speaking, every 500 miles. each 500 or 000 appearance on the odometer. 300 miles is like every week or two. nowayiamlubingthechainthatoften. chain life is directly proportional to mpg. unfortunately an inverse relationship exists between chain life/mpg, and ear-to-ear grins. tween my two prefires I can get 51 mpg or 35 mpg. 35 is betterer fun.
