What is hip now will turn to scorn. Your friends will draw away from you. "That is so yesterday" will haunt your every step.
That's the problem with these things, today's cleverness is tomorrow's stupidity. Where ever you go there will be murmurs: "What was he thinking to do such an idiotic thing?".
No, if you're going to go off and do something idiotic it's best to do it on the dl. Something like the ThermaJock:
When out riding along in freezing weather, with the howling winds and the nose in need of a good absorbent and the tips of fingers and toes turning a nice shade of coal, it must be quite comforting knowing that your crank, which is nestled in one of the 3 warmest parts of the body, has that added layer of protection.
This will never come back to bite you. Where one would brag about the new Karaneige collection they just purchased one is not likely to go showing off the latest in crank warmers. "Dude, you gotta see this!" will never be received by your friends with a hearty "Wow! Hey, can I try it on?".
But these good folks have missed an opportunity here. What is needed is an armpit warmer as well, another very warm part of the body that is being overlooked. The ThermaPit. They could sell a combo pack and call it the ThermaTool.