From BicycleRetailer.com:

When Steve Flagg reviewed his inventory reports recently, one item jumped off the page -- 27-inch tires. "We were totally unprepared for the demand in 27-inch tires," said Flagg, president of Quality Bicycle Products.

Wayne D. Gray, vice-president of KHS/FreeAgent Bicycles, noticed the same trend. "We're seeing a lot of demand for them. It's people taking their old Schwinn Varsity out of the garage and to a shop for new tires and a tuneup," said Gray from his Southern California office.

No currently manufactured bicycles -- road, mountain or hybrid -- are designed to be used with 27-inch diameter tires, but if you've got a 10-speed bike bought back in the 1980s moldering away in the basement or garage, chances are, it will need some new tall, skinny tires before it's ready to take back out on the road.

Why the sudden urge to recycle the old bicycle? The price of gas is one factor, along with the more generalized happy confluence of two mutually reinforcing motivators -- the desire to go green and the desire to get fitter. And who knows, maybe one day those tires will be made from Russian dandelions.