PROBLEM: You punctured bigtime on a chunk of glass, put in a new tube, but it pooched through a slice in the tire when you pumped it up. Boom! It blew out again.

SOLUTION: Boot that bad boy!

If a hole in the sidewall or tread is big enough to bulge when the new tube is being inflated, stop!

Before you finish and try to ride, you need to cover the damage on the inside of the tire. Use the piece of tough material -- canvas, slab of old tire casing -- that you carry in your patch kit. (You have added this to your kit, haven't you?)

Next, carefully inflate the tube so this "boot" doesn't move. You should be able to make it safely home or to a bike shop where you can replace the tire.

Another trick is to apply a tube patch to the inside of the tire. This will work if the hole isn't too big.

Uh, oh -- forgot your patch kit?

Get creative. Most energy bar wrappers or gel pouches are tough enough to work as a boot. So is a dollar bill (it's linen, not paper). Maybe pull off a piece of handlebar tape.

Or, simply scout the roadside to find a coated paper cup or other suitable piece of litter. Unfortunately, there'll be lots to choose from.