cadence control vs range...how to decide?
 

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 :D

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? 11-25 sounds fun (fast) but will I miss that 16?

Thank you for any comments :)

If you're spinning out at 28-30mph going downhill with your current gearing you probably need to work on spinning at a higher cadence. Then again, how steep a grade in how much wind are we talking? There are some descents around here that I get nailed with so much headwind I'm slower than on the flats.

One cassette isn't going to make you faster than another, per se. The thing you need to think about are how close the gears are together. With a narrower range you wont make such big leaps between shifts. Now, at a given grade with a given amount of headwind you might find that at your preferred cadence a difference of one or two teeth will make all the difference. With a larger gap between cogs you might find that one gear is slightly too low and another slightly too high.

I'd try a few cheaper cassettes before you really nail down which one is best for you. If you're a heavier person on a heavier bike carrying some extra gear on top of it your needs are going to be different than somebody with a strict roadie setup. Try a wider range cassette to start and work your way down from there.

12-26 9sp...

Use the new crank and keep that cassette. If you feel you must have a new cassette, try an 11-25

With the triple, you might be able to get away with an 11-23 if you would like some closer range gearing. Personal preference at that point.

thank you :)

I am heavier, and the bike is too...no extra gear though (for now). I DO need to get better at spinning. The roadies in my neighborhood pass me like I'm standing still when I am above my spinning-stablity limit in the highest gear. I keep my rpms between 76 and 91, try to keep it above 85 but waver a lot between 80-90.

I hear what you're saying about going wide, then narrowing down...but with a triple crank, isn't any cassette going to be pretty wide? I mean, will an 11/12-25 be pretty wide for me anyway but with closer gears than an 11-27+?

thanks again!

Ha, just as i was finishing responding to the first post... thank you for the thoughts. I wanted to keep the 9 actually but the new shifters no likey. 11-25 keeps sounding better to me, but 12-25 would have less gaps (and honestly the 11 may not be necessary for me just yet)

With a triple up front you will have a wide range overall. The biggest thing is not ending up with a cassette where you'll be shifting the front all the damn time, or needing to shift front and rear simultaneously a bunch. That gets really annoying after while. Too narrow a range and it's the former, too wide and it's the latter. So you've really got to try some different cassettes.

You don't want to end up cross chaining too much, which will reduce your chain life.

ah, right. so a 12-25 would be unwise. maybe a 11-25 or 12-27 then....

OK, DONE!

just found a 11-25 (105, 5600) on ebay for $40 shipped. this will be a start, maybe i'll learn how to customize it later on if need be. Thanks for the comments and suggestions!

:)

Me, I'd never give up my 16 tooth cog, so I'm for the 12-27. The 39 front and 16 back is about 17 mph at your cadences. The gap between the 15 tooth cog and 17 tooth is noticeable for modest riders like we are.

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.

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.