Originally Posted by
nfmisso
Why? What do you expect to gain by going from 9 to 11 ?
For the vast majority of riders, going for 9 to 11 is just taking money out your pocket with no real return.
Assuming you use the same gear range (11 - 32), all 11 speed does over 9 speed is, give you 1 tooth jumps for the 4 smallest cogs (11, 12, 13, 14) rather than for the two smallest cogs (11, 12) with the 9 speed. If you want more closely spaced gearing, you could always stick with 9 speed and go with a 12 - 23 or 12 - 25 cassette to get smaller jumps between cogs.
This is one of those things where it really only makes sense to upgrade when your drivetrain wears out, or of you are thinking about buying a new bike.