LA INTENSIDAD DE LAS CRISIS

Clincher tires are standardized by size, so, if you have a 700C rim, a 700C tire will be compatible. Tires are labeled the same way that rims are, but also the width is provided in their designation. A 700C x 23 tire has a 700C diameter and a width of 23 millimeters. The same applies for the tubes used in clincher wheels, although there is some leeway as far as width is concerned. A 700C x 18 to 23 tube (one that is designed for an 18–23 mm wide tire) will probably work fine in a 700C x 25 tire but may explode in a 700C x 34 cyclocross tire.

1

Inspect the Rim

This is especially important if you’re installing a tire on a used rim. Closely inspect the rim for damage that may prevent the tire from being installed correctly or that may damage the tube. Any burrs or gouges should be filed down until smooth.

2

Inspect the Rim Tape

The rim tape (usually made of cotton or plastic) covers the spoke holes on the rim so the tube does not push through them and tear. Make sure each hole is covered and there is no significant sign of wear. Note: Some rims, like those on Mavic’s Ksyrium and R-Sys wheels, do not need a rim strip because there are no spoke holes in the rim surface.

If new rim strips need to be installed, start by lining up the valve hole in the rim strip with the valve hole in the rim. Drop a screwdriver in the valve hole to hold the rim strip in place as you install it on your rim.

3

Install Tire’s First Bead

The tire beads are the stiff rings on the inside edges of the tire that hook onto the rim. To install a tire’s first bead, follow these instructions:

Find the tire’s label and always put the tire’s label directly over the valve hole so that if you get a flat, you can line up the tube with the tire and wheel to help determine what caused the flat. You should be able to put the entire bead of the tire on the rim with your hands, but, if the tire is

extremely tight, you may need to use a tire iron to pry the bead onto the rim. A tire iron hooks over the lip of the rim and acts as a lever on the tire to lift it onto the rim.

4

Inflate Tube and Install in Tire

Put a small amount of air in the tube (just enough to give the tube some shape, maybe 5 psi at most), and place the tube’s valve in the valve hole. Push the tube into the tire around its entire circumference.

Note: Almost all modern road bikes use tubes that have a Presta valve, but some may have a Schrader valve—the same valve used in car tires. Make sure that the valve you have is compatible with your rim. It will be obvious if you have the wrong type because the rim valve holes for Presta and Schraeder valves are very different in size.

5

Install Tire’s Second Bead

The tire beads are the stiff rings on the inside edges of the tire that hook onto the rim. Starting at the valve hole, use your thumbs to install the tire’s second bead. Hold the wheel in front of you, and pry the bead up and over the lip of the rim in incremental steps. If you become efficient at doing this, you may be able to install the entire bead with just your hands. If the last bit becomes too difficult to do by hand, use a tire lever to pry the last bit on. Be very careful not to pinch the tube between the tire and the tire lever because this will tear a hole in the tube.

6

Check That the Tire Is Seated Correctly

Put a bit of air in the tire, around 30 to 40 pounds per square inch. Check that the bead is seated correctly in the rim. If the bead is seated correctly, there should be no place where the bead is coming off the rim or where the bead is stuck down inside the lip of the rim. In either case, deflate the tire and adjust by hand.

Note: If you’re having difficulty seating the rim correctly, it may help to lubricate the tube with talcum powder. Place the tube in a self-locking bag, and put a couple of shakes of talcum powder in with it. Close the bag and shake so the tube is covered evenly. Reinsert the tube in the tire and try again.

7

Inflate Tire

Inflate the tire to full pressure (the recommended pressure is usually labeled on the tire), and recheck that the tire is properly seated in the rim. Smaller riders can use less pressure, while larger ones may need more to prevent pinch flats, but the max I recommend for clinchers is 120 pounds per square inch. Very light riders can get away with as little as 105 pounds per square inch, but I would not recommend ever going lower. Use about 5 pounds per square inch less in wet conditions to improve traction. Note: Tubes come with a valve cap and a little knurled nut that is supposed to hold the valve in place. Do you need these? No.