Bicycle Bike Repair Fix A Flat Punctured Tire by Jim Langley

by Jim Langley
Click on the picture to open the full illustration and see how flat tires can be fun. While he works, she enjoys the break from riding	From the beginning of cycling, tire companies focused on flatproof tires. The text from this 1910 ad reads, “The toughness of this tire is to be compared only to the hide of a rhinoceros” From Mead Cycle Company Catalogue No. 117 See below for detail image

Here’s What’s Needed for Bicycle Flat Tire Repair

What to carry in your take-along tool kit

A spare tube with the same valve as what’s on your bicycle (carry a second when riding on bad roads or on rainy days when flats are more common).
2 or 3 tire levers (two cool ones to consider: the Cobra Tire Tool and the Speed Lever by Crank Brothers). Note that most people use levers to remove tires, however, with a little practice you can do it by hand, which is faster and sure to impress your friends (click the link below to view my video of this and read my step-by-step instructions).
Patch kit (usually you replace the tube, but if you get multiple punctures, you’ll need patches to repair it).
1- x 2-inch denim or canvas boot (this is placed between the tire and tube to patch a tire cut). You can also purchase ready-made tire patches.
If your bike has bolt-on wheels, you’ll need a wrench for loosening the axle nuts. Otherwise, you can use your hands to open the wheel quick releases.

NOTE: You are reading my text-heavy and illustrated-by-me flat-tire-repair story. Here's my photo-and-caption one.

Click picture to see how to
open other brake types

1. When you puncture, stop riding as soon as it’s safe. If you’re riding with friends, let them know you’ve flatted so they don’t run into you as you slow down; and so they don’t just keep riding. If it’s a rear flat, shift to the smallest cassette cog while slowing. Get off, move off the road or to the side of the trail, then open your brake quick-release (road bikes) or unhook the cable on V-brakes and cantilevers (mountain bikes).

Open the brake quick-release (direct-pull brakes shown) to spread the pads and make wheel removal easier.

If you have disc brakes, there's nothing to open. The disc brake rotor (the metal disc attached to the wheel) will slide right out of the brake caliper when you remove the wheel. However, do not squeeze the brake lever while the wheel is off the bicycle or you will have to reset your brake pads, which is not always easy.

Click picture to enlarge

2. Open the wheel quick-release (QR) and remove the wheel (or unscrew axle nuts if that’s what’s on yours). For front flats, lift the bike by the handlebar with one hand while removing the wheel with the other. For rear flats, grip the seat with one hand and lift. Remove the wheel with your free hand by pushing down (or forward for horizontal frame dropouts). To keep your hands clean, try to shake the chain off the cog as you remove the wheel. If it resists, lift it off with one finger (it’s easy to clean just one finger). Then rest the bike on its left side.

On most modern forks, you’ll need to hold the round end of the QR mechanism and rotate the other end (where the lever is; or vice-versa) to create enough space to clear little safety nubs on the tips of the fork put there to keep the wheel in the fork should the QR mistakenly loosen.

3. Release any air still in the tire. If there’s a cap on the valve, remove it so you can release all the air from the tube. With presta valves, unscrew the top and press it with one finger. With Schraders, press the hook on your tire lever or whatever you have into the valve. While doing this, go around the tire with one hand squeezing to get all remaining air out. Also go around the rim and squeeze and work the tire toward the center of the rim because that’s the deepest portion of the rim (called the rim well). If you can get the tire to sit in the rim well, it’ll create slack between the tire and rim making it much easier to remove the tire (you’ll use the same technique during installation).

If you have a threaded presta valve, you may need to remove a nut at its base before you can free the tube. Schrader valves (sometimes spelled “Schraeder”) are deflated by pressing on the tip inside.

Tire levers make it easy to remove
even the tightest-fitting tires

4. To remove the tire, insert one tire lever under the tire’s edge (called the tire bead) opposite the valve stem. Wiggle it beneath the bead and pull down on the top of the lever to pry a small section of the bead over the rim. Hold the lever in place against the spokes (or attach its hooked end to one spoke if possible). Put another lever under the same tire bead about 4 inches from the first, and pry another section over the rim. Move 4 more inches, pry, and continue until the entire bead is removed. Then reach inside the tire, grasp the tube, and pull it out. To allow the valve stem to be removed, uncover it by pushing the tire away with the heel of your hand. To ease inspection of the tire and rim, remove the other bead (it should come off easily). Because you’re going to replace the popped tube with your spare, you can stuff the bad tube in your jersey pocket or seat bag to patch later.

Slide a rag or your glove
around inside the tire to find
what popped the tube

5. Before installing the new tube, it’s crucial to check the tire and find and remove whatever it was that gave you the flat. You can check with your hand, but if there’s a piece of glass in there, you might cut yourself. So, a safer way to check is to run your glove around the inside of the tire. If there’s something sharp in there it’ll snag the glove. Be sure to go in both directions, though, in case it’s a piece of wire or something lodged at an angle. Also check the tire tread visually. Remove any sharp objects in the tire or tread. If nothing snags the glove and you don’t find anything, it’s likely that whatever popped the tube has already fallen out of the tire. Also check the wheel to see if the rim strip (it covers the rim holes and/or nipples so they can’t cut the tube) has shifted allowing sharp edges to cut the tube. Make sure the strip covers every hole/nipple.

Resting the wheel on the ground
and moving both hands away
from the valve stem, work one bead
onto the rim

6. To reinstall the tube and tire, inflate the spare tube just enough to remove the wrinkles, then place it inside the tire starting with the valve stem. Lean the wheel against your shins with the valve hole on top. Hold the tire and tube combination (valve on top) with both hands, place a portion of the closest bead on the rim and insert the valve stem a quarter of the way into the rim hole. Work the bottom bead (the one closest to your body) onto the rim by moving your hands apart, away from the valve stem. Keep moving your hands and pushing down and when you reach the bottom lift the wheel and pop the one bead onto the rim. Now that one bead’s in place, tuck the tube fully inside the tire, which will make the second bead flush with the rim.

Rest the wheel on your knee and push
down to roll the last difficult
section onto the rim

7. To finish tire installation, start at the valve stem and work the second bead onto the rim. Push the valve stem up into the tire so its thick base isn’t trapped beneath the bead. Use the heels of your hands to work the bead onto the rim all the way around. It's usually difficult to complete the last section, but remember, it doesn’t take strength, just good technique. Try letting the air out of the tube. Also, go around the tire and pinch the beads toward the center of the rim, which will get them into the deeper rim section and create some slack. Don't try to pop the entire last section on. Instead try to pop on an inch at a time with your stronger hand and gradually work the section on. (If you’re using a Speed Lever, the lever does the work for you.)

To prevent damage to the valve,
brace it while inflating by wrapping
your thumb over the tire
and a finger around the pump head

8. Push the valve into the tire one more time to make sure it’s not trapped beneath a bead and then inflate the tire partially. Before completely pumping it up, remove the pump and spin the wheel to see if the tire is seated correctly on the rim. All tires have lines on the sidewalls that should be equidistant from the rim all the way around. Sight for this as the wheel spins. If either line dips below the rim edge in one spot, add air to pop it up into place. If either rises above the rim, let the air out and check to ensure that the tube isn't trapped beneath the tire bead. Use your lever to gently (don’t pop the tube!) push the tube into the tire if it’s under a bead. Then finish inflating the tire. Reinstall the wheel making sure it’s aligned in the frame or fork, tighten the wheel quick-release, close the brake quick-release and you’re ready to ride. Good job!

Patching tubes

Don’t toss your popped tubes! Patch them. They’ll keep working even after they’ve been patched a dozen times or more. But, use regular patches, not the new glueless patches. Glueless patches are best for mountain bike tubes, which don’t hold high pressure. And they’re only temporary patches. They can work for getting home. But, if you intend to rely on the patched tube in the future, do a proper patch job.

To find the hole in the tube, try inflating the tube and listening (if the hole is at the valve’s base, or if there’s a giant tear in the tube, the tube probably can't be repaired). If you can’t find the hole, place the tube in water and look for bubbles. When you’ve found the leak, mark it, or better, tear it slightly larger. That way, you’ll be able to find it (glue can make pen marks disappear).

Scuff the spot with the sandpaper in the patch kit and brush off the dust with your hand. Apply a thin layer of glue slightly larger than the diameter of the patch you’ll use. Let the glue dry for at least five minutes. Then, peel the foil off the patch and apply the patch being careful to cover the hole. Leave the cellophane in place on the patch. Knead the repair into the tube by rolling the end of your pump over it a few times. There! Now the tube is better than new; just reinforced in one spot and a tad heavier!

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