...will a Sunrace 11 cog cassette really not work in your setup ? I've always found them to be Shimano compatible in every application I've tried one in, but admittedly I'm not a big fan of more speeds are better. So I don't run anything with 11 in the back. I forget the Shimano recommended changeout intervals, but isn't it something like every other chain swap ? And isn't 7 or 8,000 miles about average life expectancy for one of their cogsets ?