Gear ratio- compact- hill climb question (long)

[anakiwa]

Hi-

I'm new to the forum and was looking for help with the gearing on a new road bike. The bike is a custom so I can choose whatever combo of components I want. I live in Vermont in a very hilly area and have decided a compact (34/50) with a 12-27 in the rear would be the best option for 99% of my riding. (My current road bike is a triple (30/42/52) with a 12-25 and I like the gear range but not the triple.) The catch is that last summer I did one hill climb race (Mt Eqinox) and loved it. For that event my exBF changed the small ring on the triple to a 26 so I had a 26 in the front and a 25 in the back- I found I spent enough of the race in the 26-25 that I wouldn't want to do another hill climb without gearing that low. Other considerations are that I have a tri-bike with 10 spd ultegra and would therefore like to stick to 10 spd shimano (likely ultegra) on this bike so I can switch things back and forth. So far the 2 options I've been given include:

#1 Set up the bike with a mountain bike rear derailler so I can switch to an 11-34 cassette in the rear for the hill climb. The catch on this is that there aren't a lot of 10 spd cassettes out there that get this large. Interloc Racing Design makes one but the only review I could find http://www.roadbikereview.com/cat/dr...6_2484crx.aspx wasn't so promising. The up side of this option is that it's a much easier switch to make.

#2 Set up the bike for regular riding (compact in front) and then plan to switch to a triple for the hill climb. The down side of this is that it's a bigger deal to swap the crank, and potentially the bottom bracket (and potentially more expensive for one day's race). I can proably get away without swapping the front derailler as long as I do the swap right before and after the hill climb (for the hill climb I'll really only need the smaller ring so the shifting on the front isn't so important as the shifting in the rear).

Any thoughts on these options? Or ideas for another way of handling this problem? Any experience with the Interloc shimano compatible 10 speed cassettes?

Thanks very much!

[Veronica]

How much switching of things between bikes will you really do?

I'm only asking because having to have 10 speed shimano seems to me to be the limiting factor.

V.

[anakiwa]

I was thinking of getting a slightly lighter set of wheels for the new bike. It would therefore be nice to be able to use the better wheelset on the tri bike for longer races. It wouldn't be all that often, but I'm more likely to want to swap wheels a few times during the season, whereas the hillclimb situation would be once (at most twice) a season.

[Cassandra_Cain]

How much switching of things between bikes will you really do?

I'm only asking because having to have 10 speed shimano seems to me to be the limiting factor.

V.

I agree with that.

Campi has some good options, like a 13-29.

[DebW]

Personally, I'd be more likely to go with option (2). Or if I went with option (1), I'd swap the RD along with the cassette to avoid that long cage when I didn't need it.

[Veronica]

I don't know what your hills are like or how strong you are, but I do know that when I decided to get a compact double on my new bike, I spent a lot of time looking at Sheldon Brown's gear ratio chart. I wanted to be sure a compact double would have the gears I need. Where I ride is downright hilly, maybe verging on mountainous...

I'm a lazy ultra distance rider. I typically don't pedal down hill if doing 25 mph. On the flat I can reach 25 mph, but it certainly isn't sustainable. So I don't need a huge gear. I went with a 46 - 33 and a nine speed 11 - 34 cassette.

I guess what I'm saying is, think about what you really want this bike to be able to do for how and where you ride. And maybe just buy lighter wheels for your tri bike so you can set this bike up as a climbing bike, if you want.

V.

[anakiwa]

Thanks for the help.

Deb- What is it that makes you want to avoid the long cage?

Could I go with a 9-speed on the new bike and still be able to switch the wheels/cassettes back and forth with the other bike (10 spd).

Veronica- thanks for the advice about the gear ratio chart- my ex-BF (we're still pretty good friends) set up an excel spreadsheet with the numbers- I've spent a fair amount of time staring at it. Where I live is quite hilly (and there's a pretty significant one on my way home so many of my rides end with a big hill). I also occassionally will go over some of the gaps in the area (1500+ feet) on longer training rides. That said I'm comfortable on hills and I think all the up and down means that I'm a little better at climbing than I otherwise would be.

In all honesty, the gearing with my current triple (52/42/30 with a 12-25 cassette) probably suits me perfectly. It gives me a relatively low gear for climbing and it's only rarely that I'm pushing the top gears (Like you Veronica, I'm not a maniac on downhills- it's only on that long gradual descent that it gets tempting to see how fast I can go). But I find that the triple often gets slightly out of alignment and I'm having to really jam the shifter to get the derailler where I want it (someday I'll learn how to adjust these things myself, but for the moment I'm dependent on the LBS or the ex-BF- who isn't around as much as he used to be). My tribike has a compact and it's always been so much easier to shift. After studying the numbers I concluded that a 50/34 with a 12-27 would get me almost as high and almost as low and that I should be able to live with that. But it's a good point- maybe I should just stick with a triple- it would certainly solve the hillclimb problem.

So here's another question- anyone have any thoughts on whether an ultegra triple front derailler would shift more smoothly than my current 105 triple front derailler? (or is the higher price simply because it weighs less?)