“In the factory, we make cosmetics; in the store, we sell hope.” - Charles Revson, founder, Revlon

I concluded recently that there is a lot of hope being sold in the cycling business when I abandoned some of mine. I have come to terms with the fact that I will never need the top gear (53 x 11) spec-ed on my Trek Equinox TTX. And, unless their nickname is “colossal quads”, I question how many triathletes really need this intra planetary, over-drive, 126.6 inch top gear. ( See Sheldon Brown’s Gear Calculator for an explanation of gear inches.) There are no sprint bonuses in the Ironman and there is that activity called the run which usually follows the biking portion of the race.

Wouldn’t most triathletes be better served giving up the 11 cog and adding a easier granny or bailout gear? I think so and did last year when I added the largest cog that Shimano makes for a 10 speed (a 12 X 27) just before Ironman Wisconsin. (It’s So Easy Having An Enormous Cog) But is that the best way? I don’t think it is.

Compact cranks, which have smaller chain rings (e.g. 50/34) and a smaller spider hole pattern (110mm versus 130mm) offer another way to get some easier gears by giving up a hard one. There is an excellent analysis of the gearing options available with a compact in this Slowtwitch article.

To summarize, a 53/39 chain ring with a 12×27 cassette provides about the same gearing as a compact crank with a 50/34 with an 11×23 cassette. The compact gives you a slightly taller top gear, you can think of it as a 53 chain ring with an 11 2/3 cog if it makes you feel better, and the basically same size granny gear. The gear spacing with the 11×23 + compact crank is more even than spacing with a 12×27 and, all things being equal, it will be a little lighter.

By themselves these small advantages probably aren’t enough to justify buying a compact cranks . So how come I own a new one? Because I can see the day coming when I’ll need BOTH compact cranks AND a large cog. Despite it’s real world advantages, I don’t expect to see compact cranks spec-ed on the TTX any time soon; reality doesn’t sell.