A new cycling friend remembered several years ago (possibly 10 years ago because we are both in our late 40s) a cycling gadget that was added to your pedals to increase the power outage at the stroke point where no power existed. The gadget looked like an egg. I have tried to google "Bicycle Momentum Egg" with crazy physic projects on rotating an egg so it spins, but nothing bicycle related.

Does anyone remember this product and if they still sell it?

Like every silly idea in cycling, if it didn't work it died. RIP

Most get reborn and called new though... like Z cranks.

Probably the device required egg beater pedals to work properly.

Together these two sound like a slightly addled description of ovalised chain rings - Shimano used to call them biopace - they went away, and seem to have come back.

Jolly your the best! Thank you for your super fine memory! Shimano BioPace is definitely it.

I don't know if you can buy Biopace chainrings new anymore, but certainly you can find them used if you look.

That said, they failed commercially and are generally believed to just be more snakeoil.

I had them on one bike -- they were on it when I got it -- and I was like ... "meh". I didn't notice any difference, good or bad.

From the OP's description I was envisioning something that was egg-shaped positioned between the pedal and crankarm....oh well. Biopace is alive and well in new and used form on Ebay. I've been running Biopace since '87 on several bikes...I actually like it.

Q-Rotors are the most popular non-round rings currently in production.

You see ovalised chainrings in the TdF occasionally - in the time trials most often. Reportedly there is a slightly higher risk of chain derailment with them - but like the advantage they offer, this may merely be plausible speculation.

They went away because they didn't work. When shimano makes a mistake they quit marketing it.

I kinda like Biopace advanced two bolt holes. I think SOME people will always prefer non-round chainrings. Seems like Shimano tried to push them on EVERYBODY, however. Suntour and SR followed suit and there for a couple of years wobbly rings were pretty much standard unless you could afford some Italian components on your bike.

I have a bike with Biopace, I like it. It is not between the pedals. It is an ovalized chainring. LC

Some people have had a bit of cycling success with them ... https://ovalchainrings.com/contents/m...tric-wiggo.png

The one thing for sure is that they will ride what they are paid to ride as long as it doesn't slow them down.

It would be interesting to see if there are any independent ( non-sponsored) studies that would show ( pro or con ) whether or not there are any real "measurable advantages" to these "ovalized" chain rings. That's the problem with stuff like this. You can't trust what the manufacturers or sellers say about the products and the buyers will either love um' or hate um'.

I tend to look at it this way; if a lot of people like the product there's a good chance that you will too. There are no guarantees though and there are always going to be people that hate the new stuff.

There was a study by Christie O'Hara when she was at Cal State San Luis Obispo. I think it was her master's thesis. I tried to find it on the web recently but couldn't. But it was there. Then she was hired by Rotor and now works there. I don't think they sponsored that study. The subjects were triathletes from Cal State San Luis Obispo.

I spoke with a pro rider in Europe back in 2009 when Cervelo Test Team was using Rotor rings. That pro rider said the science is there, its just that Rotor to be accepted by the various pro teams needs to step up their product line and do a full group. I don't think this is going to happen soon.

Then there's O Symetric, the French version of ovalized rings that competes with Rotor from Spain. That's what Chris Froome used.

Even on the Cervelo Test Team back in 2009, not all riders used Rotor rings. And Garmin Sharp riders do have their preferences even though Rotor is a sponsor. But if it were Mavic or SRAM, its a different story. All team riders would be required to use their product.

Another interesting thing would be to speak with the retired pro riders who have no chance to make a come-back because they are somehow too old, banned from competing, not selling their own line of bike related goods. Somebody like Tyler Hamilton who spilled the beans on 60 minutes. I would like to hear what he says about the bikes that he rode as a pro. It would be from both perspectives: his own as a pro rider and his thinking about the non pro riders.