You think it’s not going to happen to you. But someday it will – all it takes is one little piece of glass or a tack or a thorn.
It’s the dreaded bicycle flat.
As you train for the Iron Horse Bicycle Classic or head out on the drying trails with your mountain bike, are you prepared with the proper knowledge and gear? If you’re not one of those pampered elite bicyclists who has a sag vehicle following you with a spare wheel, you’re going to want to know how to fix that flat.
What follows is a flat-tire primer – a few basic tips to get you started and hopefully allow you to successfully complete the job.
Of course, it’s one thing to read about it and see the pictures – and view the accompanying online video – but the bottom line: Practice on your own. Do it until you feel comfortable with all these steps. Look at it this way: Practice now in your garage or apartment, or later under pressure out on the trail, with a thunderstorm bearing down.
And while we’re at it, we’ll talk about preventing flats. We’ll sprinkle in a couple of pro tips to keep everyone interested. That’s probably plenty. By then, if you haven’t taken off already, you’re going to be eager to ride.
Durango is full of good bike shops and mechanics. For this story, we stopped in at Mountain Bike Specialists, world-renowned among cycling enthusiasts.
Step 1: Removing the wheel and tire
A couple assumptions: We’ll be talking about a road bike, except where noted. Also, we’ll assume that you have along three essentials: a new tube, a tire lever and an air source (this could be a pump, but a CO2 cartridge is eons quicker). Finally, we’ll assume it’s a rear wheel, and you don’t have tubeless tires.
The first thing to think about is finding a safe spot off the road, says Darian Harvey, a shop mechanic at Mountain Bike Specialists for 11 years.
Then remove the offending wheel. Start by shifting to the smallest rear cog. You don’t have to be moving to do this; simply downshift and then spin the wheel by lifting it and turning the pedals by hand.
Flip open the brake. Open the quick release.
The wheel should fairly easily fall out of the rear dropout. Then take the chain off the cog and free the wheel. Take a mental picture, or heck, even an actual picture, of how this looks. Yes, you also will be putting the wheel back on. (See video for more tips.)
Let most of the air out of the tire. Starting on the opposite side of the valve stem, insert the tire lever and slide it around to lift the tire off the rim. Then do the other side and take the tire and tube off.
Pro tip: When you lay the bike on the ground, make sure the drive train (derailleurs and chain) is not in the dirt.
Step 2: The new tube
Be sure to remove whatever’s in the tire that caused the flat. That may mean feeling carefully along the inside of the tire.
Open the valve of your new tube and give it a few pumps or a quick shot of CO2, just to give it a little form. Insert the tube into the tire; as you position the valve stem into the rim, check the recommended tire rotation and position it accordingly.
Pro tip: Line up the tube stem with the decals on the tire so you can find it quickly.
Using your fingers, place the tire back on the rim, one side at a time. Most tires these days are pretty malleable, but for the final few inches you may need a tire lever to ease the tire bead back onto the rim. Be careful not to pinch the tube between the lever and rim.
“Check the tire again to make sure it lines up on the rim,” Harvey said, noting the slight danger of blowing the tire off the rim when air is added. “If there’s a big gap between the rim and the tire, then it’s not on right.”
Add air slowly at first with the C02, then faster when you’re confident the tire’s not going to come off the rim. If you’re using a pump, just eyeball it every so often.
Pro tip: When you’re putting the metal nut back on the tube, make it hand tight. Cranking it down just stresses the tube at that spot, pulling it through the rim hole.
Step 3: Back on the bike
“Now comes the fun part,” Harvey said. “Everybody’s scared of this, and it’s not scary.”
She was talking about putting the rear wheel back on. You can do this with the bike upside down, but her preferred method is to hold the bike upright and roll the wheel toward it. Put the chain around the cassette and line up the chain with the small cog. Slide the wheel onto the dropouts.
Pro tip: When you pull the wheel up into the dropouts, push down on the rear derailleur to move it out of the way.
When the wheel’s back in the dropouts, close the quick release and make sure the wheel spins properly. If the brakes rub, you may need to loosen the quick release and line up the wheel again.
Pro tip: Don’t forget to close the brakes. Squeeze to test them.
Harvey’s final advice: It’s a good idea to have a patch kit and know how to use that as a backup. Also, don’t leave anything behind. As you’re putting the wheel back on and gathering up your gear – saddle bag, pack, etc. – ask your riding mates to check the area.
There are three key actions to avoid flat tires, Harvey said.
Use proper tire pressure to avoid pinch flats, a common problem for mountain bikers. For road bikes, she recommends 100 to 110 pounds of pressure, and for mountain bikes, 30 to 40 pounds. This varies with weight and riding style.
Check the tires for wear. If they’re well-worn, that means less tire between the tube and the ground – and makes it easier for sharp objects to penetrate. Also, look for cuts in the tire which can lead to a tube blowout.
If possible, avoid routes that lead through construction zones, where you might pick up a nail, roof staple or something else sharp. Similarly, be wary of sharp objects on the road.