Quick google and you’ll likely see several new threads a week on here about them.
Used Rotor oval rings on the TT bike for a couple of seasons, think they help reduce fatigue mostly.
Recently stuck an AB oval on the XC bike for the first time. Didn’t notice any difference in the way it felt to pedal, though was quite surprised to feel like I could hold on to bigger gears for a bit longer than usual. Raced it for the first time over the weekend in some pretty foul conditions, did ok and no chain issues either. I’m sticking with it. I’m even quite tempted to try something with a more extreme wonky shape like the Osymetric.
must be some science to it other than them just being a bit ‘quirky’.
It’s not really that complicated. Makes the ring a bit bigger during the power phase of the pedal stroke, and a bit smaller at the top and bottom. Seems quite sensible really (and the exact opposite to the B word.)
and of course you have to adjust the pedalling style over time so they just felt weird..
Is odd that some people find this and others (like me) don’t notice any weirdness at all in feel (if anything it feels a bit smoother.) I suspect if you’ve already got a very smooth and efficient pedal stroke you’ll notice a bigger difference than if you’re a masher.