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?