Flat Tire Who?

The city can throw a lot of hurdles at your bike, and it’s usually your tires that take the brunt of it. Here’s how to change a flat tire and still make it to your destination on time.

1. Carry — and We Cannot Stress This Enough — Tools.
It doesn’t take an entire toolbox to change a flat tire in urban cycling but there are a precious few you should always have with you:

  • Tire levers: These are slender, portable levers that help you pry stubborn tires from their rims. They have several cool features that aren’t immediately obvious — more on this later.
  • Allen wrenches: If your bike has a bolt-on axle, you’ll need two Allens of equal size to remove it. Check the bolts on your axle to confirm this. Otherwise, a portable Allen set is always good to have.
  • An extra tube: Make sure you’re buying the right tube size for your bike.
  • A patch kit: If you don’t actually need to replace your tube, as is often the case with pinch flats, you can quickly patch it up and carry on.
  • A pack to hold your tools: Perhaps the most important item on the list is the bicycle seat pack, which allows you to keep all of your gadgets on hand until you need them. Unnoticeable and easy to strap on, it’s also a great place to store your cards and cash when you go for a long haul through the hills or around town.
  • Mini-pump: This nifty tool is about 10 inches long and has the same circumference as a hot dog, yet it could inflate a tractor tire if needed. Conveniently, you can connect it to your downtube so that it’s perfectly in line with your bike’s aerodynamics. If you want rapid inflation, you could sub the pump out for CO2 canisters, but they’re a bit wasteful because they only work once.

Keep in mind that without your tool pack, if you get a flat, you’ll have to walk your bike to work. Get the tools, store them under your seat, and forget about them until you need them.

2. Loosen Your Axle.

Try biking to your workplace on a weekend. Measure how long it takes to ride at a moderate pace — there will undoubtedly be days when you need to make up for a bit of lost time. Try a different route on the way home and compare the two.

3. Take the Wheel Off.

If you have rim breaks, start by releasing the tension in your brake assembly. Do this by either squeezing the arms of the brake together and slipping the knob out of its notch, or by flipping the quick-release lever.

If you’ve got a flat on your rear wheel — and that’s where most flats happen — you should shift your chain to the smallest gear. This puts minimal tension on the chain. Then pull back on the derailleur arm to move the chain away from the cassette and pull the wheel out.

4. Release the Pressure in Your Tire.

Loosen or unscrew the air valve on your wheel and release pressure. For Schrader valves (the older type), you’ll need to depress the tiny rod within the valve. For presto valves, unscrew the top and then press down to release air.

5. Remove the Tire from the Rim.

Volumes could be written on unseating tires from rims, but it basically comes down to these steps:

  • Try it by hand first. Starting on the top of the wheel, with the air valve closest to the ground, press the bead edge toward the center of the rim.
  • Start with your first tire lever. At the same location, dig one of the levers under the bead and flip the handle downward. This will bring the bead over the rim’s edge. Use the hook on the opposite end of the lever to latch onto the nearest spoke, which will keep you from losing progress.
  • Use the second lever to work your way around the rim. With the first lever in place, slide the second lever under the exposed bead and work your way in one direction down the rim.

Go until the tension is released. Once you’ve removed enough of the bed around the wheel, you’ll feel the tension release. Now you can pull the bead entirely off the rim and remove the tire.

6. Inspect Your Tube for the Cause of the Flat.

Your tube could have gone flat due to a long-vanished, sharp object or a piece of glass that’s still lodged in it. If you see twin holes across the width of the tube, you likely experienced a pinch flat — that is, a flat caused by hitting a sharp protrusion in the road, which pinches your tube between the tire and the rim. This is often called a “snakebite” due to the two side-by-side holes.

If the holes are too small, they may be hard to find. Inflate the tube and wet your lips. Rotate the tube in front of your lips until you feel the air blowing on them.

If the exterior or interior of your tire is damaged, go to a repair shop to determine if it needs replacement.

7a. Patch Your Tube.

Get a patch kit and follow the instructions. It’s quick, easy, and fun.

7b. Replace Your Tube.

If the hole is significant or if multiple holes make it hard to patch, use a new tube. Ensure your rim strip is in place and partially inflate the tube to give it shape.

Ensure your tire is oriented in the right rolling direction. Place the tube inside the tire and insert the air valve through its hole in the rim.

Start at the valve, and push the tire bead into the rim. Using both hands, work your way down either side of the wheel to seat the bead. More tension will build as you go, and you may have to use a good deal of force to complete the final stretch. Do the same for the other side.

Note: Be especially careful not to pinch the tube between the bead and the rim during this process.

8. Inflate the Tire.

As you inflate your tire back to the proper pressure, check both sides to make sure it’s properly seated. The valve should be straight and not at an angle.

9. Put Your Wheel Back On.

Perform step 3 in reverse, pulling back on the derailleur and then lowering the wheel into place if it’s a rear wheel. Make sure it’s securely in its notches before tightening its axle. Reattach the brakes.

10. Flip the Bike Over.

Your bike should be good to go!

Works Cited: “How to Fix a Flat Bike Tire.” REI. Retrieved July 30, 2019, from https://www.rei.com/learn/expert-advice/flat-tire.html