Chainrings don’t last long in the winter mud do they? Some say they’re made of cheese! The way ramped chainrings are designed they’re meant to be fitted one way only. The big ring especially often has a bar that goes behind the crank arm so that should the chain come off it cannot slip down between the crank and the ring. Now, bear in mind that most cyclists do not/cannot pedal with equal force throughout the 360 degress rotation of the cranks then the chainrings become worn more through the ‘power phase’ than through the ‘resting phase. Or, they become worn more just after ‘top dead centre’ where you get more power down than they do anywhere else.
When your chainring is sufficiently worn your chain starts to jump. But always in the ‘power phase’ where the rings are worn most. So what’s to stop you rotating the chain rings through 90 degrees to even out the wear? Nothing really. Especially if you’re not in the habit of changing under load. Shifting efficiency should be affected, but I can’t really tell the difference, and like I’ve said before….Riding budjet is finite, and when itâ€™s gone itâ€™s gone. What you spend on mundane stuff you canâ€™t spend on groovy stuff, so scrimping will help you get a little more miles for your moolah.