Nice to see some intelligent threads on BG over the last few weeks.
He also openly uses a sitting pedaling style and elliptical rings, both of which have the potential to really help.
Hey G, excuse my ignorance but what are elliptical rings? Oval chainrings? What advantages do these offer and if there is a significant difference why don't we use them in everyday cycling (or BMX for that matter)?
Just that. Rings where the teeth are arranged around an ellipse rather than a simple circle.
The reason we dont see them used that much (though the popularity is really growing now) is that Shimano had a crack at it in the 90's and made a total arse of it. They put the offset in the wrong orientation.
The idea is that you cant push in the top and bottom dead-spots so you want to get through those areas as quickly as possible and with less resistance. So at these points you have a diameter that is like a smaller ring, then in the places where you can really put the power down, you have a larger diameter.
I made myself an elliptical ring for my MTB about a year ago now and wouldn't go back now. For an MTB, especially when climbing, it is amazing, much easier to pedal up hard technical sections because you are much less likely to get stuck at the dead spot.
I would happily run one on my BMX, chain tension is unaffected (if you get it right) and there is no reason your chain would be more likely to come off. Would be great for places where you have limited time to get your run up to speed, however on grinds it sticks down lower than normal so that isnt ideal.
Die-hard road bikers say that they "feel" strange and claim they are less smooth, but I think that this is actually more down to them being used to an unsmooth cadence from the round so when they try elliptical it being smoother feels weird. If you are actually putting any power down then an elliptical ring clearly offers better "matching" to the kinematics of your leg movement than a round one does.
G.