joelt wrote:
I have a Ultegra 12-25 cassette and a Ultegra 11-28 cassette. I was wondering if anyone has had any luck using the final 21-24-28 sprocket from the 11-28 cassette with the 12-25 cassette by replacing the final 21-23-25 from the 12-25 cassette.
Joel
I've done this a lot with 6700 cassettes; it should work fine with 6800 too. My experience with mixing and matching Shimano cassette cogs is that - as long as you stay within the group set (mix Ultegra cogs with Ultegra cogs, for instance) you're ok. I've tried mixing and matching 6700 and 5700 cogs and ran into some problems - I tried putting a 21-24-27 from the 105 cassette in place of the 6700 21-23-25 and it just wouldn't shift right. Something to do with the Hyperglide ramps and pins not matching up correctly.