The Duckmeister wrote:Shimano don't make 11-27. They do however have 12-27 or 11-28. The 28 will only play nicely with current-generation (7900 down to 4600) derailleurs; on anything older it will bash teeth on the big sprocket. 2012-model updated 5700 105 & new 4600 Tiagra will take up to 30T; SRAM Apex & updated Rival will accept 32T.
Yeah I have a 28 11 SRAM Force cassette (and run red-black dereailleur) and its pretty borderline in the 28, it works but makes
some pretty funky noises. I really only got it for stratford dargo, and wouldnt want to ride that cassette on the flats due to
big jumps in ratios (gotta love your cadence going from 90rpm top 115 in one gear change)