wintershade wrote:
I did IM Whistler last year. I'm ~3 watt/kg with a compact and 11-29 cassette. Switching to the compact was kind of a last minute decision a couple weeks before the race, when I panicked after a horrible brick run after my long 100 mile training ride. At the end of the day, I appreciated having the 34 front ring. A 50x11 is plenty of gear. If you're spinning that out, you may as well be coasting. To go any faster is a huge waste of energy to overcome the air resistance. The only time you need a bigger gear is if your riding in a group and trying to catch a downhill breakaway, or if you have a 1000+ watt sprint.
That said, what I didn't appreciate was I found myself riding cross-chained a LOT more on the 34/50 than 36/52. It was pretty annoying actually. If I were to do Whistler again, I'd have kept the 36/52 up front, and swapped for a medium cage RD with an 11-32 cassette (or 11-30 if you're a very strong climber and proven runner off the bike). It gives you almost as much range and a straighter more efficient chain line. Yes there are some bigger jumps, but they're all at the top of the cassette, where I find I actually like of like bigger jumps.
For weaker riders in the sub 2.8 watt/kg range or riders who have done very little low cadence training, maybe the 34/50 makes sense. I didn't like it. I moved it to my "climbing" bike, which rarely gets ridden, and even for that bike I'm thinking about selling the compact rings going with a medium cage RD and 11-32 instead.
You can look at this the other way too - I'm a strong cyclist (roadie only) that uses a 50-34 and I like it because it allows me to be in my big ring almost the entire time and closer to the middle of my cassette for the majority of the terrain I encounter.
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