Originally Posted by
alanknm
I ride with 11-28 and it works fine for me. I seldom use the 28 and I've had people tell me that I should switch to 12-25 but it's useful sometimes for those short nasty steep hills where I ride.
There's no reason why you couldn't go to 11-28. I see that Shimano CS-6700 (Ultegra) has 11-12-13-14-15-17-19-21-24-28 that is supposed to work fine with your existing rear derailleur.
Are you sure it says CM 5600 ? CS-5600 is Shimano 105 (2010). According to the Shimano website, you can use a 105 11-28 (CS-5700) or the Ultegra (CS-6700) cassette.
No, I'm not sure. I was looking at it last night in dim light - it said "** 5600 HG Hyperglide Shimano Japan". Perhaps it is "CS". Maybe it is a 105 cassette after all? It won't be until tonight, when I get home from work, that I can look again (drat, I should have brought my bike with me).
Another question - can I change the individual gears, say, swap the 25t for a 28t gear on my cassette (and maybe the gear below it for better spacing)?