How long 'till everyone "must have" these?

nothing new, these have been around for a-while.

Without really studying them, the concept seams legit. I think someone on here has used them? maybe Shane?

My 1986 Centurion Dave Scott Ironman has the Shimano BioPace cranks which I think are somewhat the same idea, maybe just implemented differently. Even though that bike is steal, not aero and weighs at least 8 pounds more than my 2013 carbon Trek Madone, it still rides very nearly as fast. I kinda wish I could put those chainrings on the Trek . . .

wonder if the positioning would need to be tuned per rider because everyone strong point of the rotation may be in a different spot. also wonder how it effects wear and tare on the drive train

I think your first question is a very good one. If anyone knows, please post.

Lots of people I know have these chainrings, my SO included. I had biopace on my first bike, but even though those aren't round chainrings, they are different.

http://cyclingtips.com/2012/09/osymetric-gimmick-or-miracle/

Edited by jeng 2016-07-22 11:24 AM

It's based on leverage not on each persons biometrics. Everyone will have the maximum leverage at the 3 o'clock position. so then it a matter of figuring out exactly when the diameter should start to increase and decrease , maybe that's symmetrical on either side of 3 o'clock and maybe not. I assume the design would do some testing or studies to see and which leg positions the average person had the most power and balance that with the leverage arm position to come up the best geometry.

I never used them on my MB, but off-round chain rings made an appearance back in the mountain biking scene probably as far back as the late 80s.