You are riding along peacefully, everything is going well… and suddenly, your tire starts to deflate. A flat tire!
If you are new to cycling, your first instinct might be to look for the nearest workshop. However, changing an inner tube is a fairly simple repair, even if you have never touched bicycle mechanics before.
With a few tools and a little method, you can learn to do it yourself. And most importantly, prevent a small puncture from ending your ride.
Here is how to proceed, step by step.
WHAT DO YOU NEED TO CHANGE AN INNER TUBE?
Good news: there is no need to own a complete toolbox.
To replace an inner tube, you will need:
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A new inner tube, suited to the size of your tire.
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Two or three tire levers, preferably made of plastic so as not to damage the rim.
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A bike pump compatible with your valve.
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Possibly a wrench to remove the wheel if your bike does not have a tool-free quick-release axle.
A quick tip: always check the dimensions indicated on the sidewall of your tire before buying an inner tube. Also, pay attention to the valve type: Presta or Schrader.
STEP 1: REMOVE THE BIKE WHEEL
Start by placing your bike in a stable position.
If the puncture is on the rear wheel, shift to the smallest cog on the cassette before removing the wheel. This will make disassembly and reassembly easier.
Then, open the thru-axle, quick-release, or nuts, depending on your bike.
On a bike equipped with hydraulic disc brakes, avoid pulling the brake lever while the wheel is removed: the pads could move closer together and complicate reassembly.
STEP 2: FULLY DEFLATE THE TIRE
Even if your wheel already seems flat, there may still be a little air left in the tube.
Open the valve and let the remaining air out.
Then, press the sidewalls of the tire toward the center of the rim. This helps unseat the tire beads and makes removal easier.
This little trick can save you from having to force unnecessarily with the tire levers.
STEP 3: REMOVE ONE SIDE OF THE TIRE
Gently slide a tire lever under the edge of the tire, then lift the bead over the rim.
If necessary, use a second tire lever a few centimeters further along.
Once part of the tire is off, work your way gradually around the wheel.
Caution: there is no need to remove the tire completely. To change an inner tube, it is generally enough to release only one side.
Also, avoid using screwdrivers or other improvised metal tools, which risk damaging the rim or the tube.
STEP 4: REMOVE THE OLD INNER TUBE
Start by pulling the inner tube out of the tire, then gently remove the valve from its hole in the rim.
But before installing the new tube, take a few moments to understand what caused the puncture.
This is arguably the most important step of the entire repair.
A small piece of glass or a thorn may still be stuck in the tire. If you don't remove it, your new tube could puncture within the first few meters.
Carefully inspect the inside and outside of the tire, as well as the rim tape. Run your fingers cautiously along the inside: a glass splinter can be very sharp.
If you find the hole on the old tube, its position can help you locate the culprit in the tire.
STEP 5: INSTALL THE NEW INNER TUBE
Before inserting it, inflate the new inner tube very slightly to give it a round shape.
This prevents it from twisting or folding inside the tire.
Insert the valve into the rim hole first, then gradually place the tube into the tire.
Take your time: it should be evenly distributed all the way around the wheel, without being caught under the bead.
STEP 6: REINSTALL THE TIRE WITHOUT PINCHING THE TUBE
Place the tire bead back into the rim, starting opposite the valve.
Work your way around with your hands, little by little.
The last few centimeters can be a bit difficult, especially with new tires or tight beads.
The trick is to push the already mounted part of the tire into the central channel of the rim to create some slack.
Try to finish by hand rather than with a tire lever: this will reduce the risk of pinching the new tube.
Before inflating, check on both sides that the tube is not visible between the tire and the rim.
STEP 7: INFLATE AND CHECK THE WHEEL
Inflate the tire gradually.
Stop at a moderate pressure first to check that the tire is correctly positioned around the entire circumference of the rim.
You can then reach the pressure suited to your tire, your weight, and your usage, without exceeding the limits indicated by the tire and rim manufacturers.
Reinstall the wheel on the bike, tighten its axle correctly, and check that the wheel spins freely.
Finally, test the brakes before heading off.
And there you go: you are ready to get back on the road!
THE 4 MISTAKES TO AVOID WHEN CHANGING AN INNER TUBE
Some small mistakes can turn a ten-minute repair into a second flat tire.
1. Not checking the inside of the tire. If the thorn or piece of glass is still there, the new tube will not last long.
2. Mounting a completely deflated tube. It can fold or get pinched between the tire and the rim.
3. Forcing with a tire lever during reassembly. This is a frequent cause of pinching the tube.
4. Forgetting to check tire positioning. An improperly installed bead can cause poor inflation and make the wheel dangerous.
SHOULD YOU REPAIR OR REPLACE AN INNER TUBE?
Both solutions are possible.
A small puncture can often be repaired with a patch, provided the tube is in good condition.
However, if the valve is torn off, if the tube has a large tear, or if it is very worn, it is better to replace it.
For bike rides, the most practical approach is generally to carry a spare inner tube. You can always repair the old one at your leisure back home.
THE SMALL PUNCTURE KIT YOU SHOULD ALWAYS HAVE WITH YOU
No need to carry your entire workshop.
A suitable inner tube, two tire levers, and a small pump are enough to solve many common punctures.
You can store it all in a compact saddlebag, along with a multitool for small adjustments.
This kit takes up little space and can save you from a long walk home.
NEED A HELPING HAND? STOP BY ROUTES&ROADS
Changing an inner tube quickly becomes a simple task with a little practice. But if your tire is particularly difficult to remove, if you get flat tires regularly, or if you are not sure which tube to choose, it is better to ask for advice.
At Routes&Roads, our workshop can help you identify the cause of a puncture, check the condition of your tires, and choose the right accessories for your rides.
📍 Routes&Roads — 14 Place de Rungis, 75013 Paris
A flat tire should never be the end of your adventure. With the right techniques and a small repair kit, you can get back on your way with full confidence.
