OBERSON GUIDE
How to Fix a Flat Bike Tire
Inner tubes, punctures, tire pressure, and tubeless setups: learn how to fix a flat bike tire step by step.
AT A GLANCE
How to Fix a Flat Bike Tire
To fix a flat bike tire, remove the wheel, take out the damaged inner tube, and inspect the tire and rim for debris that may have caused the puncture. You can then replace or patch the tube before reinstalling the tire and inflating it to the recommended pressure. Before continuing your ride, make sure the tire is properly seated on the rim and that the wheel is securely reinstalled. For tubeless setups, small punctures may seal automatically, while larger ones may require a plug or an emergency tube.
What tools do you need to fix a flat bike tire?
To fix a flat bike tire, you’ll need tire levers, a pump or CO2 inflator, and either a spare inner tube or a patch kit. Carrying these essentials can help you handle most punctures on the road, trail, or gravel path without needing assistance.
| Tool | Purpose | |
|---|---|---|
| Tire levers | Help remove the tire from the rim | |
| Pump or CO2 cartridge with inflator | Reinflate the tire after the repair | |
| Spare inner tube | Fastest way to repair most flats | |
| Patch kit | Repair small punctures | |
| Multi-tool | Remove certain wheels or adjust components |
How do you remove the wheel?
Start by removing the wheel from the bike so you can access the tire and inner tube. The exact process varies depending on your bike and axle system, but most wheels are secured with either a quick-release lever or thru-axle. Quick-release wheels use a lever that opens and loosens the wheel. Thru-axles must be unthreaded and pulled out before the wheel can be removed.
Rim Brakes versus Disc Brakes
If your bike has rim brakes, you may need to release the brake before removing the wheel. Disc brake systems don’t require this step.
Front Wheel
Release the axle mechanism and lift the wheel out of the fork.
Rear Wheel
Shift the chain onto the smallest cog before removing the wheel. This creates more space around the derailleur and makes the wheel easier to remove. Pull the derailleur slightly backward as you guide the wheel out of the frame.
How do you remove the tire and inner tube?
Fully deflate the tire before removing one side of the tire bead from the rim and pulling out the inner tube. This gives you access to the puncture and helps prevent damage to the tube or tire during removal.
Deflate the tire.
Release all the air from the inner tube before removing it. Schrader valves can be deflated by pressing the small pin in the centre of the valve. For Presta valves, loosen the small threaded tip before releasing the air.
Remove the tire bead.
Push one side of the tire bead toward the centre of the rim to create slack. Some tires can be loosened by hand, but tighter tire and rim combinations may require tire levers. Start on the section of the tire opposite the valve and carefully work one section of the tire bead over the edge of the rim. Once a section is free, the rest of the tire can usually be worked off by hand.
Remove the inner tube.
Once one side of the tire is off the rim, pull the inner tube out carefully, starting at the valve. You may have to unscrew the valve ring to remove the inner tube. If the tire was completely removed from the rim, keep track of its direction before reinstalling it. Be careful when pulling out the valve to avoid damaging it.
How do you find what caused the flat?
Before installing a new tube or patching the old one, inspect the tire, tube, and rim carefully to identify what caused the flat. Leaving debris inside the tire can quickly lead to another puncture.
Check the tire.
Inspect both the outside and inside of the tire for sharp objects, such as glass, thorns, small rocks, or metal fragments. Run your fingers carefully along the inside of the tire to feel for anything embedded in the rubber. Tweezers can help remove small pieces of glass or debris.
Check the inner tube.
Inflate the tube slightly and listen or feel for escaping air. Small punctures can sometimes be difficult to spot, so placing the tube near your cheek or submerging it in water can help reveal slow leaks.
Check the rim and rim tape.
Inspect the rim for sharp edges, exposed spoke holes, or damaged rim tape that could puncture the tube from the inside. If the rim tape has shifted or torn, it may need to be replaced before reinstalling the tire.
Should you replace or patch the inner tube?
Replacing the inner tube is usually the fastest, easiest way to fix a flat bike tire when out on the roads and trails. Many cyclists carry a spare tube and patch the damaged one later at home so it can be reused as a backup.
Replace the Tube
Best for
- Fast roadside repairs
- Larger punctures
- Damaged valves
- Getting back on the road or trail quickly
Patch the Tube
Best for
- Repairing small punctures at home
- Reusing damaged tubes
- Emergency situations without a spare tube
Replacing the Tube
Install a new tube if the old one has a large tear, a damaged valve, or multiple punctures. Before installing the new tube, make sure the tire and rim are free of debris that could cause another flat.
Patching the Tube
Patch kits can repair many small punctures successfully. Before applying a patch, locate the leak, dry the area completely, and roughen the surface slightly with sandpaper so the adhesive bonds properly. Allow the glue to become tacky before applying the patch.
How do you reinstall the tire and inner tube?
Partially inflate the tube.
Adding a small amount of air helps the tube keep its shape and reduces the risk of twisting or pinching it during installation.
Reinstall one side of the tire.
If the tire was completely removed from the rim, push one side of the tire bead back into the rim before inserting the tube.
Install the inner tube.
Insert the valve through the valve hole in the rim, and place the rest of the tube evenly inside the tire without twisting it.
Reinstall the tire.
Starting opposite the valve, work the second tire bead back onto the rim. Pinching both sides of the tire toward the centre of the rim can make the installation easier.
Check the tire before inflating.
Make sure the tire bead is seated evenly on the rim and that the tube is not trapped between the tire and rim. Gently massaging or rolling the tire can help centre the tube and seat the tire properly.
How do you inflate the tire properly?
Inflate the tire gradually and check that the tire bead remains seated evenly on the rim as the pressure increases. Inflating too quickly or to the wrong pressure can increase the risk of another flat or damage the tube.
Most tires include a recommended pressure range printed on the sidewall. Use that range as a starting point and stop inflating immediately if the tire appears uneven or the tube seems trapped between the tire and rim.
Once the tire is fully inflated, check that the valve remains straight and that the wheel spins normally.
How do you reinstall the wheel?
Place the wheel back into the frame or fork, and make sure the axle is seated properly before tightening the quick-release lever or thru-axle.
Front Wheel
Guide the wheel into the fork, and tighten the axle securely.
Rear Wheel
Place the chain onto the smallest cog, and guide the wheel back into the dropouts on the frame while pulling the derailleur slightly backward.
Final Safety Checks
If your bike has rim brakes, reconnect or close the brake before riding. Spin the wheel to make sure it rotates freely and check that the brakes work properly before getting back on the road or trail.
What if your bike has tubeless tires?
Tubeless tires use liquid sealant inside the tire instead of a traditional inner tube. They’re especially common on gravel bikes and mountain bikes because they can reduce the risk of small punctures and allow riders to use lower tire pressure for added comfort and grip.
Small punctures in tubeless tires often seal automatically while riding. Larger punctures may require a tire plug or an emergency inner tube, depending on the size of the damage and the repair tools available.
FAQ — How to Fix a Flat Bike Tire
Can you put an inner tube in a tubeless tire?
Yes. If a tubeless tire cannot be repaired with sealant or a tire plug, installing an inner tube is often the quickest way to get back on the road or trail. Before inserting the tube, check the inside of the tire carefully for debris or sharp objects, and remove any tire plugs that could interfere with the tube or cause another flat.
Why does my bike tire keep going flat?
Repeated flat tires are often caused by debris left inside the tire, low tire pressure, damaged rim tape, or improper installation of the inner tube. Small pieces of glass, metal, or thorns can remain embedded in the tire and puncture a new tube immediately after installation.
Pinched tubes can also cause repeated flats if the tube becomes trapped between the tire and rim during installation. Checking the tire, rim, and tube carefully before reinstalling everything can help prevent recurring punctures.
How often should you check bike tire pressure?
Bike tire pressure should be checked regularly, since tires naturally lose air over time. Road bike tires should be checked before every ride or at least every few days. Gravel, hybrid, and mountain bike tires can usually go a bit longer between checks depending on the setup and riding conditions.
Temperature changes can also affect tire pressure, especially after cold nights in a garage or shed. Riding with tire pressure that’s too low increases the risk of pinch flats and can result in poor handling and tire damage. Use the recommended pressure range printed on the tire sidewall as a starting point.
Do you always need tire levers?
No. Some bike tires can be removed and reinstalled by hand, especially if the tire and rim fit loosely together. However, tighter tire and rim combinations often require tire levers to remove the tire.
Should you replace your tire after a flat?
Not necessarily. Most flat tires are caused by small punctures that can be repaired without replacing the tire itself. However, tires with large cuts, damaged sidewalls, excessive wear, or visible threads may need to be replaced for safety and reliability.
Inspect the tire carefully after every flat, especially if the puncture was caused by sharp debris or impact damage.
Can you ride on a flat bike tire?
Riding on a flat bike tire isn’t recommended. Doing so can damage the tire, rim, or inner tube. A flat tire will make the bike harder to handle and increase the risk of a crash.
If you get a flat during a ride, stop as soon as you can do so safely, and repair the tire before continuing.
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