Originally Posted by
nfmisso
Consider a 13-26T 13-14-15-17-19-21-23-26 (very even jumps) cassette instead.
48/12 = 4 ~ 53/13 = 4.1 ; a 52/13 would be exactly the same as a 48/12
38/21 = 1.8 42/26 = 1.6
I would not go with the Shimano 12-25 because of the 12-13-15-17-19-21-23-25 <> that 13 - 15 jump is not nice.
The problem for me with a wider range cogset like that is that, at least with 42/53 rings, I always seem to be cross-chained. Ideally, I like to have as many gears as possible between roughly 65-85 gear inches, and I rarely use anything outside that range. I also dislike having to do a lot of double shifting.
So for your example, if I was on the small ring, I would use the 14 - 17 cogs. On the big ring, I would use the 19 - 15 cogs. In both cases, in terms of an ideal chainline, I would be at the wrong side of the cogset for the ring (granted, not as bad for the big ring), and in both cases I would miss having a 16t cog.
I am starting to realize why I like the 1 x 6 drivetrain on my Raleigh so much.