Or “Tyre”, for you continental types.
I’ve been riding my bike to work for the last year and a half. Since I’m doing it more for the transportation and the exercise than for the fun of it, the mechanics of dinking around with the bike to keep it going have little appeal to me. Our local bike shop, Pedal Power, is manned by a great bunch of folks who do a wonderful job of relieving me of most of the boring maintenance work. They have, however, refused to send out a representative to my house once a week to check on my bike’s tire pressure for me. (Well, no, I didn’t actually ask them. There’s a point when the embarrassment about being a lazy slug actually outweighs the laziness itself.)
So I had an idea: a valve stem that would capture some of the kinetic energy from the tire’s motion and use it to keep the tire inflated at an optimum pressure. Lo, behold: someone’s beaten me to making something of the sort (which should come as no surprise: see my earlier point on being lazy). Nakano Iron Works has built a hub that does essentially what I wanted. It’s a bit more involved to install than a valve stem would be, but I have hopes that it will start coming preinstalled on bikes in the future.