Originally Posted by
monkeydentity
Background:I'm converting my hybrid for the road and I'm trying to understand which cassette will suit my needs. I know this is a topic that comes up a lot, but I haven't been able to find the answer appropriate for my setup. A quick nod to one or the other would be hugely appreciated, then I'll hurry back to the hybrid and clyde forums until i'm FAST
Current Setup: 48-36-26, 12-26 9sp....(just bought new 30-39-50)
Current Status and Riding Style: The weird MTB gearing I have now is adequate for the hill in Prospect park, in fact I rarely use my 26 on the front, but I want to ride centuries and I'm hauling some extra weight that many in here might not be. On the other end, I do spin out on the downhill when I reach about 28-30 mph and would love some more pull there. I've been trying to regulate my cadence carefully so I don't want big jumps.
Question: Which 10sp cassette is the best mate for my new 105 (5603) 30-39-50 crank? I don't know how to calculate the range and I'm not sure how important x,y, or z gear is...a 12-27 seems like nice range, but do I really need all that with a triple?
This all depends on what your mean maximal power curve looks like, how much you weigh, how steep and long your hills are, what your preferred cadence range is, what happens in terms of fatigue when you go outside your preferred cadence range, etc.
Personally I wouldn't use any gearing combination that didn't have one tooth jumps up to the 19 cog.
With 10 cogs that allows 11-21, 12-23, or 13-26. Choose rings to match.
As a spinner I've been plenty happy with a 13 starting cog for the last 15 years. 50x13 is still a 30+ MPH cruising gear (past that you can just tuck) and 39+ MPH sprinting gear. In the 8 speed living in Boulder, CO I rode 50-40-30x13-14-15-16-17-18-19-21 so I wouldn't need to change cassettes depending on whether I was riding west to the Rockies or east on the plains and switched to 50-34x13-14-15-16-17-18-19-21-23 in the 9 speed era as things wore out.
11-25 sounds fun (fast) but will I miss that 16?
If you're strong enough to use an 11 cog you don't need anything bigger than a 21, especially with a compact or triple.