How to Fix a Flat Bicycle Tire
Tires don’t get enough credit when talking about bicycles. If you think about it, it’s the tires that take you to your destination.
The concept of the wheel is older than history itself. Wheels allow for efficient riding, and without them, you won’t be going anywhere. But like any bike part, tires get worn out over time.
For one, they take the most wear from the road. And this gives any biker one potential caveat: flat tires.
Although it’s an inevitable part of cycling, fixing deflated wheels shouldn’t concern you. This is especially true if you have the tools, good practice, and a little knowledge.
This post will walk you through how to fix a flat bicycle tire and what causes it.
But first, what are bike tires?
The tire is the firm rubber casing mounted on the rim of a bicycle. It’s open in the centre and has two rigid and fairly sharp edges for mounting onto the rim.
By itself, it’s incapable of holding air, and this is where the tubes come in. Made of rubber, a tube is just the right size and shape to fit inside the tire, and it has a valve in it for inflation.
When inflating tires, you’re actually pumping air into the tube, filling in the tire. Also referred to as carcass, the tire is what meets the road.
Tires provide traction, handling and control. Moreover, they resist punctures, offer good wear, and withstand sunshine, ozone and rain.
Despite the offered endurance against the road consequences, wear and tear are imminent. And when it comes to replacing or repairing tires, there are common reasons:
- You’re not pleased with how your bike rides, and thus a new rubber will help.
- The ones you have now have worn out.
- The worst-case scenario: flat tires.
If you find yourself in situation #3, you’ll want to know what has caused it and then fix the problem.
What causes flat tires?
(Image Credit: Wikimedia Commons)
Let's get our terms straight. It’s actually a flat tube and not a flat tire. Unless, of course, you’re riding a rare tubeless road bike or a fat-tired mountain bike.
Either way, you’re going to be changing the tube on the inside of the tire and not the tire itself. And these tubes go flat with a protective layer of thick rubber tires around them.
The main culprit is whatever sharp items are on the road. Sometimes it’s a staple or wire, or it can be a glass, a rock, or just a big dump.
But generally, you must fix the tire when it’s getting old, e.g. after the first 1,000 or 2,000 miles. It also gets thinner in time, providing a less protective barrier for the tube.
And occasionally, you can get a bad tire or tube, and if that’s the case, you’ll know it right away, mostly on the first ride. For this reason, it’s best to give yourself a 10-day lead time to try out new tires before the big ride.
How to Fix a Flat Bicycle Tire
Thinking ahead and taking some time to learn how to change a flat helps. The hassle of fixing it may be annoying but not the end of your ride.
Here’s a step-by-step guide to save you the trouble:
Prepare the tools
Put together the basic materials required to fix your flat effectively. The things you need depend on whether you’re riding tubeless or tubed.
For tubed tires, you’ll need the following:
- Mini pump, even better with a hose;
- At least two CO2 cartridges and inner tubes;
- Valve extension, particularly if you’re riding aero rims;
- Tire levers;
- Tube patch kit.
For tubeless, prepare the following:
- A mini pump with a hose;
- At least two CO2 cartridges and inner tubes;
- Tire levers;
- Tubeless tire repair kit.
Step 1: Remove the wheel from the bike
If you have tubeless tires and the needed repair kit, you may skip this step. Otherwise, remove the wheel.
Check the damage and see if it’s a simple puncture or not. If it’s the latter, where plugging it won’t suffice, flip the bike upside down to detach the wheels from the frame.
Removing the rear wheel is a bit more challenging than the back, so take your time. To begin, release the brakes. Squeeze the brake arms together to ease the tension on the cable.
If you have a quick-release level on the brake, open the lever. Next is to release the wheel from the frame.
Using a quick-release axle, open and hold the level while you unscrew the nut on the opposite side. Use a wrench to loosen the bolt.
Then, remove the rear. Shift your chain onto the smallest cog of the rear cassette. If you have rim brakes, open them, so the tire doesn’t get stuck when removing the wheel. (For disc ones, you won’t need to release the brakes.)
Pull open the lever and spin it to loosen it. You may also need to unscrew the nut on the opposite side.
Push the rear derailleur back, so the chain lifts away from the cog. Lastly, remove the wheel from the dropouts on the bike frame with your other hand.
Top tip: Practise taking the wheel on and off as often as possible. The more you do it, the easier it will be in the actual situation.
Step 2: Remove the tubes
You have to deflate your bike tire completely, and you can do this one of two ways, depending on the valve:
- For a wider Schrader valve, press down on the small in the centre of the tire valve.
- As for a thinner Presta one, remove the plastic dust cap first. Then turn the small valve at the top counterclockwise and press down to release air.
Next, unseat the tire bead, found at the edge of the tire under the rim. Do this by pushing the bead edge toward the rim centre and working your way around the rim.
Or, use a tire lever; start on the section opposite the valve to avoid damage. Use the longer end of one tire lever to pry the bead up and over the rim edge.
Once a part of the tire bead is free, remove the rest with your fingers. Then begin detaching the inflatable tube from beneath the tire.
Pull the valve stem out through the rim first, and the rest should slide out easily when pulled.
Step 3: Determine the cause of flat
Inspect the tires and tube for punctures, cuts or tears. For the tire, start on the outside and work your way in.
Using your thumb and index finger, thoroughly check the outside treat and the inside of it. If you find something, check the tube at the same approximate location to see if there’s damage.
For the tube, spotting the damage can be a bit tricky, but inflating it does the magic. Feel for air or listen for a hiss to check for escaping air. Or submerge it in a bucket of water and look for bubbles.
But if the valve system or base is cut, cracked or severely worn, it may leak. If that’s the case, the entire tube will need to be replaced.
As for the rim, look for protruding spoke ends inside or areas where the tube may have been pinched.
Top tip: Add a pair of tweezers to your bike repair kit to remove small items for your tire or tube.
Step 4: Patch the problem (if necessary)
If you prefer pinching a few pennies or wish to be resourceful, patch the tubes. Invest in a patch kit, as it comes with everything you need.
Start by cleaning the damaged area, then rough the surface using emery cloth or sandpaper. Next is to stick the patch; it can be either glueless or glue-required.
Apply it as if you’re putting on a plaster. Peel off the backing, place it over the hole and press with firm pressure.
If it requires glue, add a thin layer of the paste to both tube and the patch. Once the sticky substance has reached a tacky consistency, place the patch firmly.
Note: Some flats are simply too severe to patch. In such cases, you’ll need to skip this step and install a new tube.
Step 5: Install new/patched tube
To reinstall the tube, use a pump to inflate it just enough to keep its form. This allows for easier installation and reduces the risk of pinch flats.
Begin with the valve system. Put the tube on the rim and insert the stem straight through the valve hole.
Carefully work the tire back onto the rim by rolling the bead away using your hands. Upon reaching the valve stem, wrap the sides of the tire bead low into the rim.
Then push up on the stem to get the tube into the tire. Take extra care to ensure the tire bead isn’t pinching the tube.
Step 6: Inflate the tire
You can use either a CO2 cartridge, a minipump, or both. CO2 cartridges are best for inflating to higher pressures.
It’s also a good idea to practise tire inflation at home using one to avoid blowing out your tube. The key here is to ensure the inflator is well connected to the valve system.
A mini pump, in contrast, makes a smart backup method and an easy alternative. A pump with a hose is recommended, as it allows for better leverage and higher pressures.
Once you inflated your desired PSI, double and triple check the bead and see if it sits in the rim right. If everything is in its proper place, you may reattach your wheel.
Step 7: Reinstall the wheel
To attach the front wheel, line up the fork dropouts with the wheel’s axle. Gently lower the fork onto the axle. Push down on the handlebar to check for the proper axle placement.
Hold the quick-release level in place as you tighten the bolt. If the lever closes too easily, open it and tighten the bolt a bit more but don’t overdo it.
If your flat occurred on the rear wheel, lay the chain top around the smallest cog on the cassette. Make sure the frame dropouts line up with the axle.
Push the wheel back into the frame and then pull the derailleur down and back, so it doesn’t get in the way. Once the wheel has been properly replaced, close the quick release (and rim brakes if applied). Or insert the thru-axle into the frame and hub and thread it shut.
The final test is by lifting the rear wheel and spinning the cranks. If it runs smoothly, then you know you’re good to go!
Note: Always find a safe place, away from traffic and possible dangers, before working on your bike.
It’s easy to take bicycle tires for granted. Until you’re in a situation where balance, climbing and descending are crucial. And that’s when you begin to understand their importance.
Getting a flat tire in the middle of your expedition is the last thing you want to happen. For you to get going, you must ensure the wheels are always in good shape.
But this shouldn’t be a concern now that you already know how to handle it. Sharing is caring, so share this guide on ‘How to Fix a Flat Bicycle Bike’ with your fellow cycling enthusiasts!