Stand-over height
First, check the stand-over height. To do this, stand over the top tube of the bicycle and lift the bike with both hands. For a road bike, you should see between 1 inch and 3 inches of clearance between the tires and the ground. This rule of thumb also applies to touring bikes, commuting bikes and hybrid bikes. If you are riding a mountain bike, you may want more than 3 inches of clearance.

Saddle height and fore/aft position
Next, adjust your saddle height, using the saddle quick-release lever or an Allen wrench. The ideal saddle height allows you to reach the bottom of the pedal stroke with a slight bend in your knee. You never want to reach full extension, as this can cause pain and stiffness on the inside of the knee. Conversely, you don't want the saddle too low, as this can cause pain on the outside of the knee. Aim for about 5 degrees of bend in your knee, or about 90 percent of full extension.

You will also want to adjust the saddle's fore/aft position. You'll notice that the bike saddle has rails, which can slide forward and backward in the seat post. If your saddle is too far back, you can injure your hamstrings; if it is too far forward, you may develop knee pain. The ideal saddle fore/aft position allows your kneecap to be directly over the ball of your foot at the front of the pedal stroke. This adjustment can also be made with an Allen wrench -- the seat post generally has one or two Allen bolts holding the rails in place.

Saddle/handlebar spread
Once you've determined that the saddle positioning is correct, check the distance between the saddle and the handlebars. Stand over the bike again, and have a friend hold the bike for you. Sit in the saddle and grab the handlebars. You should be able to comfortably reach them with a slight bend in your elbows. If you can't reach the handlebars, the reach is too long. Too long of a reach can result in lower back pain. On the other hand, if you can't comfortably extend your arms, the reach may be too short, which can cause pain in the neck and shoulders. Reach can be adjusted somewhat by switching the size of the stem -- the part that attaches the handlebars to the rest of the bike. Stems come in varying lengths, generally measured in millimeters. They also come in varying angles, which allow for variance in handlebar height.

If you determine that you need a different stem, have a local bike shop change it out for you, as a new stem will also require an adjustment of the headset -- the bearings in the front of your frame that allow the handlebars to turn the wheel for steering. The shop can also give you further tips about how to properly size your bike.

Follow these tips, and you'll be on your way to a great bike fit. Remember: The best bike in the world is the bike that fits you properly. See you on the road!

Meghan Pinch is a volunteer at Bike Works in Seattle. Founded in 1996, Bike Works is a nonprofit dedicated to building sustainable communities by educating youth and promoting bicycling. Learn more at bikeworks.org.