22 mai 2008

EZ Tire Installation

Here in western Colorado last week we had 45-mph wind gusts -- the kind that make your hair hurt and requires riders to keep an eye out for cattle troughs flying like Frisbees.

What can possibly be worse ?

How about mounting clincher tires that seem impossibly small on impossibly large rims ?

It's been known to bring grown men to tears. So I'm going to try to reduce the anguish by telling you my secrets. Then you can look cool to your pals when they just can't get the job done.

Talc is the key ingredient to mounting any bike tire, particularly folding road tires with tight Kevlar beads. Talc (baby powder) allows the tube to move freely inside the tire so it doesn't interfere with the tire/rim interface. Tubes get pinched and punctured when they become trapped between a tire lever and the rim. Generous use of talc (corn starch works too) dramatically reduces this risk. Always dust the tube with talc !

Okay, now here's my easy-mount procedure :

• Place one side (bead) of the tire on the rim. That should be pretty easy. Align the label with the valve hole to look pro. Add just enough air to the tube to give it shape. Push the valve stem through the rim and feed the rest of the tube into the half-mounted tire.

• Back at the valve hole, start seating the other bead, working with both hands around the rim in opposite directions. If the tube has too much air it'll become obvious. Let out a little. Use your thumbs to push the bead onto the rim. That's what thumbs were designed for.

• At a certain point it'll become difficult, leaving a small section of tire unseated. Breathe in and let out a Ninja cry. Won't go? Squeeze the seated beads together all the way around the wheel so they go into the rim's deeper center. Let out any remaining air. Breathe deep again and try Ninja cry No. 2. If your thumbs are shot, grip the stubborn section with both hands together and try to push/roll it on with your palms.

• Still won't go? Then you must resort to the dreaded tire lever, a sure sign of weakness and a troubled childhood. When I use them (hey, I never said I had a perfect upbringing) I slide the lever (plastic preferred) along the braking surface of the rim under the bead so I don't pinch the tube, then I gently pry the bead the rest of the way. "Gently" may not be part of your repertoire at this point. Thumbs or palms are best, and patience is a virtue, but a tire lever does have its place.

• After the tire is on, push the valve stem up inside, then pull it down again. Go around the wheel, flexing the tire side to side as you look into the rim to be sure the tube isn't trapped under a bead.

• Start pumping air, then stop every 20 psi or so to check for places where the tire might be lifting off the rim. That means the tube is caught under the bead. If you ignore it, the explosion will be loud enough that you'll need to change your chamois and have your hearing checked. Let the air out and massage those sections to get the tube inside. Then gas 'er up !

This procedure should take about 4 minutes. Well, maybe 10 if you don't squeeze tennis balls.

Remember, use talc ! It's truly the key to making tire installation as smooth as a baby's behind.


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Guy Maguire, webmestre, info@veloptimum.net
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