Originally Posted by
unoudid
That's what I'm confused about. I have the 105 (11-28t) and see no reason why the ultegra (11-28t) would not work. I'm just looking at the specs on the shimano website and it state the ultegra cassettes are only for ultegra/DA. Could this be more of a marketing thing?
if you already have an 11-28 cassette and it's working fine, i don't see how there could possibly be an issue.
shimano's tech docs also say you should only use shimano chains with shimano cassettes/other stuff, and that's total baloney. i'm sure they would rather have you buy an ultegra RD with your ultegra cassette, but for RD alignment/shifting purposes, all shimano 11-28 cassettes are identical as far as i know.