I have one on my Fat Bike and it really does help to climb. I like the one I have. I also don't have a problem with Bio pace.

I'm trying to find that grad student study. Tons of data, showed zero disadvantage, advantage ranging from 0% (non-fit riders0 to 5-6% for very fit riders. This was on Rotor rings, not BioPace.

What was interesting to me was she was a cyclist and set out to prove there was NO advantage to the Rotor rings. She ended up moving to Europe and was employed by Rotor to convince teams to use those rings. No idea how that came out, as it was a few years ago.

Again, my TT buddy uses both Rotor and Absolute Black (but in red) and swears by them. He is very limited in endurance (bodybuilder), so he wants to very fast, for as short as possible, and he really is pretty fast over about 10 miles.

Durham Elliptical came on a Nishiki I had a long time ago.
You didn't need double front rings, because it worked so well, they said.
.

For the full performance upgrade, you'll need to team them up with some Dpardo cranks.

Rotor actually made some cranks before they made oval chainrings where the left and right crank arms were connected by linkages so that the cranks would not be 180 degrees apart at TDC.

Q-rings are pretty expensive just to try, although supposedly there's supposed to be a company enforced 30-day satisfaction guarantee return policy to let you try them. There are cheaper options coming out of China if you just want to try oval rings.

Sugino also had their version. Cycloid.

I saw one of those after my colonoscopy.

Oh boy, now you all got me reading smart stuff from folks with a bunch of letters after their names. Skip to the last page and paragraphs..... "told ya so" -
lol


Oval-shaped Chainrings: Evidence challenged

I'd still try one. There are a couple of time trial segments where I'd rarely get out of the big ring. It'd be easy to determine whether it works within just a few rides. Over the past couple of years my power with round chainrings is pretty consistent, factoring in wind, etc. Any measurable difference would indicate a BioPace or other oval ring works for me.

You know when he brings up biopace that he has a bone to pick and cares little for facts. He seems to neglect to note that biopace has the opposite orientation of other oval rings until a footnote at the end. He then uses it as anecdotal evidence, alongside a quote from Sheldon despite Sheldon's page that he directly quoted mentioning that fact. Froome and Wiggins don't get paid to ride oval rings, this is why the logos are always blacked out. This is fairly common knowledge and easy to find out, it's mentioned in many news articles. In fact it is mentioned in the Business Insider article he is whinging about. He also unnecessarily but very deliberately includes a quote about power meters as if it proves something. The actual reason for the power meter quote is that Team Sky is sponsored by Stages which does not calculate power accurately with oval rings, which makes his job crunching numbers harder.

Whether or not oval rings offer some sort of benefit, the way he has structured his argument is extremely dubious and dishonest. It is intellectually lazy at best, but seems to be much more likely to be intentionally misleading and deliberately deceptive.

How about in a 1x application? Any increased chance of dropping the chain?

Odd and they look like the cranks on my elliptical trainer, I have no idea why a crank would be shaped like that; it seems like a way to add weight to the crank versus a straight line form the pedal axle to the bottom bracket.

Those crankarms are bent "backwards" from every other set of "bent" arms I've seen.

The theory I've concluded might be beneficial is lost here, since the arms won't flex into a longer length under increased load (which would in effect somewhat simulate the BioPace ring's behavior).

I owned one of the bikes fitted with the Durham ellipitical and they were LYING! That crank, once you got going made the bike bounce, like crazy. I could not believe how horrible they felt. So, my advice is fogedaboudit! Round is just fine, in my book, unless some rocketsurgeon can prove otherwise...

No surprise that they couldn't be pedaled smoothly at even a normal cadence, since the % variation (scaled from the photos) is roughly +/-30%.

Compared to Biopace which can be either +/-3.5% or +/-8% depending on the particular style of ring.

French maker Reydel offered ovoid chainrings for Stronglight cranks.