Originally Posted by
tomato coupe
Yeah, if you spend most of your time below 20 mph, the 11-34 looks like a better option. (I suspect that applies to the majority of the general cycling population.)
The 15 should be good to about 23mph at normal cadence. Beyond that many are going down hill and you have to ask you self if having a selection of 4 or 5 gears for that range is warranted or you simply need 1 or two gears to push against, like the 11-34 provides. Me, I'm good with the 11 and 13 in the 11-34 cassette. Cant think of a single time I really needed/ wanted a 12 rather than 11 or 13.