One of the most common reasons for a bike to sit unused is a flat tire. I know, because I am just as bad about it as anybody else. I just got a new (used) bike and started using it, and a week later I had a flat. So, I started using my old one-speed. I procrastinated, but when I finally got around to doing it, it took me about 5 minutes. Of course, I have a quick-release front tire, so it might have taken 6 minutes if I had actually had to use wrenches to remove it. I feel kind of weird telling other people how to do something I have been doing since I was a preteen, but since I am going to be showing my mother how to do this pretty soon, I know there are people who don’t know how to do it. Here it is, in a few quick steps:

1. Remove wheel from bike.
2. Let all the air out of the tire (if you have a valve core remover, that works really well!)
3. Slip a tire lever or screwdriver between the tire and the rim and pry edge of wheel over rim. It’s best to use a dull one so that you don’t poke new holes in the tube. Continue around the tire doing the same thing until you have one entire edge of the tire off.
4. Push the valve stem into the tire, reach under to pull it out the rest of the way, and then pull the whole tube out, being careful to leave in the fabric or rubber rim strip. This protects your tube from the ends of the spokes. At this point you have a couple options: you can either spend $2.50-$5 and just throw a new tube in, or you can spend 99 cents and patch the tire. Patching the tire doesn’t take that long, and I personally would go that route. If you’re just going to replace the tube, skip to step 11.
5. Unless you can tell where the leak is, fill the tube with air. Sometimes you will be able to tell where the leak is just by the escape of air. If you can’t, fill up a sink with water and immerse the tube a section at a time, working around the tube until you see bubbles. Sometimes, the leak will be very slow, and it will take a bit more looking because you’ll only get a bubble every few seconds. Pay special attention to the valve stem. Sometimes a loose core can be the only problem.
6. Figure a way to mark the spot. I usually just hold my finger on it, but you can mark it with chalk or whiteout or something too.
7. Let all the air out of the tube.
8. Using sandpaper, a knife, or a scraper made especially for this purpose, rough up the area around the hole. If it is near the seam on the tire, try to wear down the ridge.
9. Smear the rubber cement around the hole, about an inch and a half square. Let it dry, then apply the prepared side of the patch to the tube (the side with the colored peel-off), working any air bubbles out. It’s suggested that you put talcum powder on the patch when you’re done, but that’s just to keep the tire from sticking to any exposed glue, so dirt or flour will do the same thing. (Or you can skip this step and use one of those new-fangled peel and stick patches.) If you don’t have a patch kit, I believe you can use a piece of an old tube (about an inch square) to do the patch. In that case, you have to rough up both the tube and the piece of tube, put rubber cement on both and let them both dry a little, and then stick them together.
10. Check the tube for more holes (using the submerging in water method).
11. Put the valve stem back through the hole in the rim and wind the tube back around the wheel.
12. Using the tire lever or screwdriver, pop the tire back into the rim, being especially careful not to puncture it.
13. Make sure the valve stem is straight, then fill the tube with air.
14. Place the tire back on the bike, making sure to center it. Either use one hand to center it while using the other to tighten it, or, if you have help, center the tire by having someone apply the handbrakes, then tighten the tire yourself.

Most of this info isn’t really needed for newer bikes. I picked up a newer mountain bike for $15, and when I went to patch the tire, I didn’t end up needing one tool. The wheel even pretty much centered itself when I put it back on. But for those of you who are still riding old beaters (I commend you!) it’s all there.

HINT: The two most important maintenance tips for your bicycle are to keep full tires and to oil all the joints of your bike, especially after it rains or snows.

Tuning Up Your Bicycle As you know, a person riding a bicycle is the most efficient animal on earth in terms of travel for energy expended. We are also the most efficient machines by the same criteria. To attain that efficiency, bicycles must be a compromise of weight and expense. Therefore they are fragile and need frequent adjustments. A tune-up is the package of small repairs and adjustments which are applied from time to time to keep your bike in top shape.