Originally Posted by
alan s
I just converted a triple to 1x11 with a 34T chainring and 11-40 on the rear for commuting and trail riding on my Troll. Really don't ever need to pedal faster than 24 mph, because above that, I'm coasting. The simplicity of shifting only the rear is great. Takes all the planning out of shifting without having to worry about the front. And the XT RD can go up 4 cogs per shift, so shifting to an easier gear is quick. Still, I don't have any issues with a compact double on the front, especially when combined with an 11-40 on the rear.
Personally, the only gearing system that I find goofier than compact doubles are 1x systems. You
really coast above 24mph? I can hit 25mph without even trying within half mile of my office. If I put any effort into it, I can go over the point where the speed sign at my work no longer gives a number (35mph). On a day with wind, I've been known to hit 45 by the time I reach the speed sign. Coasting at 25mph drives me batty!
Originally Posted by
Andy_K
I tried a 50-34 compact crankset on one of my commuters a few years ago and hated it. If you're a regular participant on these forums, you've probably seen me ranting about the superiority of triples over compact doubles. And yet, I somehow talked myself into buying a compact crankset again. My thinking was that the bike it was intended for would primarily be a weekend road bike and I could probably tolerate the 50-34 on the few occasions I rode it to work. Well, I've ridden it to work twice this week and I'm not tolerating it very well. It's usable, but apparently I can't use it without feeling compelled to rant. So here I am.
I'm a nerd, so I thought I'd plug some numbers into a gear calculator and see if I was missing something. Doing so, it's clear to me why 50-34 sucks so badly for commuting. Here's what the Sheldon Brown gear calculator tells me my speed will be at 90 rpm for my current gear options:
I typically cruise around 18 mph on rolling stretches of road, maybe getting up as fast as 25 once in a while. So if I start in the small ring from a stop (about 20 times on my 10-mile commute) I'm very likely to want the big ring sometime before I stop again, but probably not long before I need to stop again. Each step on the 34T ring gives me an absurdly small bump in speed, but let's say I get up to around 15 mph before I decide to jump to the big ring. Now I'm in the 34-16 combination cruising around 15 mph and to find a good next step after changing to the big ring I need to downshift the rear three times because it would have required four downshifts to stay in approximately the same gear. Who thought that would be a good idea?
The thing that really struck me about this today is that the more cogs you have in back, the worse this problem gets. I think I'm starting to understand why everyone suddenly started thinking 1x11 was a good idea.
Anyway, I'm curious to hear from anyone who has a 50-34 on their commuter and is happy with it. What is your typical usage pattern like?
I agree with you completely. I would like to point out, however, that while the gear calculator on Sheldon Brown's site is good,
I find this one to be better. It's more visual and it allows for simple comparisons between different drivetrains. The example I've linked to is your gearing and a "cross over" gearing pattern with the same range but better shift pattern. "Cross over" gearing should not to be confused with "cross chaining". A "cross over" gearing pattern is one where you pedal and change gears as needed until you need (or want) to go to a lower range. Then you "cross over" to the next higher range. For example: Looking at the example in the link above, if you were pedaling in the 48/19 combination and needed to downshift, "crossing over" to the inner ring would give you the same gear as downshifting on the back. It's an easy system to learn and comes in very handy. Sure there are lots of duplicate gears but you really can use the unique gears on the compact double all that well without a lot of double and triple shifts at a time when you don't want to be double and triple shifting.
I chose the 11-36, by the way, to give you the same range as the compact double has. That might be a stretch for a road rear to handle but you could use a Wolf Tooth Road Link to extend the range of the derailer. Alternatively, you might be able to use a mountain 9 speed rear derailer and/or the Wolf Tooth Road Link to accomplish the same thing. Alternatively, you might be able to use Wolf Tooth's new cable adapter to use a Dynasys derailer with STI. Or you could use the 11-29 system you have and live with the smaller range. You can easily play with all of these on the calculator I've linked to.