No matter how careful we are, a puncture is bound to happen.
At first, a flat tire is a bit of a nightmare when you’re out cycling. But once you’ve learned how to repair them quickly, you’ll soon be able to put that fear behind you.
Did you know that your inner tube can be repaired up to 3 times before needing to be replaced? This has a double effect: economic and eco-friendly.
Whether you’re out on the road or at home, I give you below my method and the tips I use on every flat repair, as well as the right moves to limit the risk of puncturing your tires.
Let’s get started.
The tools you need
You’ll need a repair kit to take with you on your rides. Small but essential, it includes the following items:
- 1, 2, or 3 tire levers
- Patch, glue, and sandpaper kit
- A bike pump
A good plus if you’re at home (or really brave while riding), then use :
- A basin of water
- Marker pen
In the case of a tubeless puncture where the sealant has not worked, there are 3 possible solutions:
- Repair with plugs strips
- Repair using patches
- Install an inner tube
If you’re not sure which method to use for tubeless tires, read our article on how to fix a tubeless tire.
How to fix a flat bike tire – Step-by-step
Please understand that we’re talking here about repairing a punctured inner tube, not a tire in the strict sense of the term. That said, it is possible to repair a tire, often with tubeless tires.
Remove the wheel from your bike
To work correctly, removing the wheel from your bike is essential.
To do this:
- Place the drivetrain on the small sprocket and the small chainring in the case of a rear wheel;
- Loosen the quick-release fastener or nuts;
- Remove the wheel.
Many people deflate the tire so that it can pass between the brake pads. In principle, this isn’t necessary since you’ve got a puncture. But be aware that most calipers have a pin to release the cable or a way of freeing it from its stop.
Remove your bike tire
With the inner tube trapped between the tire and the rim, it’s time to take them apart.
I recommend removing both the tire and tube from the rim.
Although it’s possible to slide the tube between the rim and the tire, it’s easier to check their condition when both are free.
I usually place the first tire lever a few inches from the valve. To the left or to the right, depending on which hand is stronger. Being right-handed, I place it on the right to open the tire clockwise.
Insert it between the tire and the edge of the rim and lever. The tire may release directly. If it doesn’t, use a second or third tire lever, then successively pry away from the valve.
If the tire still doesn’t release, repeat the process, gradually moving away from the valve.
Only use bicycle tire levers, as their design allows them to be positioned correctly and to bend in the case of excessive stress.
Once one side of the tire is fully open, remove the inner tube, ending with the valve. Then free the second sidewall by hand, without tools.
Check the components
Once you’ve released the rim, tire, and inner tube, check them.
Make sure that the rim base is not damaged, exposing the spokes, which can cause a flat tire. Also check that no sharp objects have been left in the tire, such as thorns/glass/metal fragments.
Find the air leak
The easiest way to spot a puncture is to inflate the inner tube slightly, dip it in water and look for bubbles.
Alternatively, hold it up to your mouth or ear to feel or hear the air escaping.
Note that in the case of a pinch puncture, there are always 2 holes next to each other.
Above all, never pressurize a bare inner tube. We often think it’s easier to find the hole, but the rubber expands and you won’t be able to push the tube into the tire afterward. It happened to me once, not twice.
Once you’ve found the leak, mark it so you don’t lose it. I use a Typex, the white shows up well on the black… But a marker works just as well.
Fix the leak
Once you’ve identified the leak or leaks, it’s not rocket science.
- Rub the inner tube lightly with sandpaper to ensure the glue sticks. This removes a little material and makes the pen marks disappear. Remember to redo them directly to avoid losing the hole.
- Apply a layer of glue and spread it well – the tube heel is very effective for this. Wait for the glue to dry, as this is essential for it to hold. An indicator: the glue is tarnishing.
- Place the patch with the hole in the middle and pinch firmly to ensure adhesion. You can then remove the plastic film and proceed with the reassembly.
Fitting the inner tube
You don’t need any tools to put your inner tube and tire back on, even if it’s difficult at first.
You’ll see, after some changes, you’ll get it right every time.
Start by placing the tire in the correct direction, with the “pros” placing the tire mark in line with the valve to make it easier to locate for future inflation.
- Install the first bead (end of the tire sidewall) on the rim;
- Inflate the inner tube slightly to help position it;
- Insert the valve into the appropriate hole in the rim;
- Place the inner tube inside the tire;
- Start fitting the second bead wire, starting at the point diametrically opposite the valve;
- Simultaneously approach each side of the valve;
The technique here is to place the part of the tire close to the valve on the ground and apply vertical pressure by sliding the tire bead into the rim.
- Finish by checking that the beads are evenly seated in the rim and that the valve is perpendicular to the rim;
Now, proceed to inflate your tire, respecting the pressure recommendations often indicated on the sidewall:
- For more details on the ideal pressure for a road bike tire, read our article;
- Read our article to learn everything about the right mountain bike tire pressure.
My tips for repairing a flat
As this is something I do on a regular basis, and as I’ve decided to repair tubes rather than replace them systematically, I’ve made this operation commonplace.
In other words, once you’ve got the theory down, a few extra hands will make all the difference.
Here are the three points that saved me time and tubes.
- When removing the tire, pinch the beads to place them in the center of the rim. This makes it easier to insert the tire levers.
- Use 3 high-quality tire levers
- When refitting, place the wheel vertically with the valve at the bottom and close the tire by simultaneously sliding the beads into the rim from top to bottom. Apply slight force to gain maximum slack for the last few inches.
FAQ
How much does it cost to repair a flat bicycle tire?
The average cost of repairing a flat bicycle tire is around $15 if you have it done by a professional. If you decide to do it yourself, expect to pay around $5 for the repair kit and $8 for a new inner tube.
Why can’t you ride a bike with a flat tire?
The risk of riding with a punctured tire is, firstly, to fall. Secondly, damage your tire and wheel until they become permanently unusable.
How do you know whether a bicycle tire is flat or just needs to be filled up?
To find out whether your tire is flat or just needs air, simply open the valve and check whether air is coming out. If not, it’s flat. Even in a “very” low-pressure tire, there’s always a little air left.
Why do you need to re-inflate your tire regularly?
An inner tube is made of rubber, which is a porous material, so over time it tends to lose a little air. We recommend adjusting the pressure every 2 weeks. But check regularly that you don’t have a slow puncture.
