How To Fix A Flat Bicycle Tire

A few of the items can be found in any home:

• ball-point pen -- for marking, the importance of which I'll explain in a bit
• talcum powder -- to de-stick the sticky from glue-on patches (though I don't always do this, and I've not had any problems
• tire gauge -- to check tire pressure, unless your pump has one built in

Remove the wheel from the bike. If you have large tires, you may have to release the brakes to clear the tire. Mark the position of the valve stem on the tire.

With the tire levers, pry the bead of the tire off the rim. The levers hook onto spokes to hold them in place as you work your way around until the tire is loose. Just loosen one side -- there is no need to remove the tire completely.

Pull out the inner tube. Mark it to show which side is up.

Put some air in the tube and hold it up next to your cheek. Apply pressure with your hands as you work your way around the tube, and you should hear where the air is leaking out or feel it blowing on your cheek. If not, try spitting on the tube or wetting it with your water bottle and look for bubbles. Rarely, you will have to wait until you can submerge it in a sink full of water (you did bring an extra tube, didn't you?)

Now it's time to patch the hole. Scuff the area around the hole with the scuffer or sandpaper. This gives a better grip for the glue.

Apply a thin layer of glue to the tube, covering an area slightly larger than the patch. Allow to dry completely; it only takes a couple of minutes. (Skip the glue if you're using self-adhesive patches.)

Apply the patch, pressing firmly and smoothing down the edges.

Dust with powder, so the extra glue won't stick to the inside of your tire.

Here's where the pen markings are important. You don't want to fix this tube again, so you'll want to find out what made the hole. Quite often, the culprit is still sticking in the tire. Making sure the pen mark on the tube is facing up, lay the tube on top of the tire and line up the valve stem with the mark on the tire. Now the patch you just applied will show you where to check the tire for that thorn or piece of glass. After you've removed the offending object, go ahead and feel inside the tire for anything else that might cause a problem. Make sure to shake out any sand or debris from inside the tire.

With all the air out, insert the valve stem through the rim and push the tube into the tire. Put just enough air into the tube to straighten any twists.

Tuck the tire bead into the rim all the way around. The last little bit can be hard to get on. If you can't push it on with your hands, use the tire levers to pry the bead over the edge. Be careful doing it this way! The lever could pinch a hole in the tube.

Make sure the bead is set properly and evenly in the rim all the way around on both sides of the wheel. Inflate the tire to the recommended pressure, place it back on the bike, and you're ready to roll again.

Most pumps have a lever to lock onto the valve stem; some have a threaded end to screw on. During my perimeter bicycle tour, I had an issue with the lever-lock style. The levers kept breaking at the hinge, rendering the pump useless. I went through four pumps in four months. Finally, I found a pump with a threaded end. It cost more, but it lasted the final four months of the trip and is still going strong.