Some of us at kolo t.c. may have been bugging US AbsoluteBlack distributor BTI for the past six months about these. And we’re excited.AbsoluteBlack has been one of the leading brands in out-of-round chainrings (thanks for that term, Gary) for a few years now, but like their competitors, Wolf Tooth Components, had a pretty massive hole in their line-up. While they smartly dealt with the myriad offsets, bolt patterns, bottom brackets and crank types, they didn’t offer some important sizes. In what they called their ‘cyclocross’ range, they offered 38t, 40t and 42t, but then the next single ring direct mount option jumped all the way up to the crooked dinner plate 50t Aero elliptical.
Yours Truly has spent the last two years on a 40t for a cyclocross bike, and punctuated much of the 2016 season on a 50t, both elliptical, from AbsoluteBlack. While they are NOT paying for this post, I will say one thing: there’s something to this elliptical thing. I first rode elliptical on a fat bike in 2015, but by 2016, had gone elliptical on everything. Even my two brief affairs with 2x drivetrains (a 50t/36t Ultegra set up and 50t/34t Rival) were ovalized. If you want to try them, I have the outer rings for both Ultegra and Rival bouncing around in my parts box.
We aren’t going into the whole Biopace thing, because it’s not Biopace. It’s the opposite of Biopace, really. Oval chainrings allow for more traction, less time in the dead part of the pedal stroke and, in my theory, a slightly higher cadence. That’s about as scientific as it’s going to get, and there’s an important qualifier on all of this. All of this assumes you can pedal smoothly, or as evenly as possible, on most terrain and in most conditions. If you pedal like a kicking, drunken wild person, the degree of ovality, tooth count or manufacturer isn’t going to help you.
A lot of miles went into examining all this, and on the whole, it jives with the ride. But the perfect tooth count for a gravel or road bike was still unavailable. Our guinea pig, and all around pig, Sean Kickbush, committed to the ultimate test. Sean raced a 46t ring at Barry-Roubaix and on every ride all spring, summer, and fall. From the short, steep climbs of Barry-Roubaix to the slightly downhill, 35mph+ Lighthouse sprint on TNR, the 46 gave enough range with an 11-32t cassette that even Kickbush couldn’t complain.
AbsoluteBlack is available through BTI, and odds are your local bike shop can order for you.
What ring should you get? Follow your heart, but before you do that, use this handy Gear Calculator.