Sunday, November 29, 2015

smaller big ring

On one of my recent group rides, I noticed a friend was tooling along in 53x11 top gear. Now, this was on a downhill... but the cadence looked like it was about 20rpm, far from the 60-to-100+ that's the ideal (of course, how much does it matter on a downhill?).

I used to grind up hills in my 50-tooth big ring. But I've seen the error of my ways, and now I'm more likely to spend most of the ride on my smaller, 34-tooth ring. These days, when I have the chain on the big gear in the front, I rarely use anything other than the three biggest gears in the back.

I've had it rattling around the back of my head that this is inefficient, and that I might want an even smaller large ring in the front (standard gearing is 53/39 in the front; modern road compacts are 50/34). The standard cyclocross double is 46/36, but I'm reluctant to add those two teeth on the smaller gear; I LIKE my low gear! I USE it!

One of my bike blog gurus is Dave Moulton (no, the Moulton you're thinking of is Alex Moulton). I've had a link to Dave's blog over there on the right for years, and he'll never know how tickled I was to meet him at the 2014 Philly Bike Expo. I came across one of his posts about replacing his big ring with a 46. From his post:

Even with a “Compact” crankset with 50 – 34 chainrings, the 11 speed rear cassette comes with a 11 or 12 tooth top sprocket. And the 12 x 50 gives me a top gear of 112 inches, which I can guarantee I am never going to use.
Even more frustrating, the gears I use most, the ones between 65 inches and the upper 70s, fall all the way over on the large inside sprockets of the cassette, when using the 50 tooth chainring, and the other extreme when using the inside 34 chainring and outside small sprockets on the rear.
Riding most of the time with my chain out of line just causes unnecessary wear on chains and sprockets.

He found one for his Campagnolo setup, and apparently it works for him. I can get either a Shimano or FSA for my cranks for about $45 plus shipping. The only things that are stopping me:
  • I'll have to adjust the derailleur, which MIGHT mean re-cabling, which MIGHT mean tearing off the nifty (but already slightly soiled) yellow tape that was a gift from Snakehead;
  • I'll probably have to shorten the chain... so maybe I'll wait until it's time to change the chain anyway, and
  • With Christmas coming, I can think of better ways to spend the money. I mean, I'm glad I'm employed, but I'm hardly wealthy, knowwhumsayin'?
Still, I expect I'll be gearing down by spring.

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