How to fix a bike puncture and mend an inner tube
Become your own mechanic and banish the fear of getting a flat out on a ride.
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Getting a flat tyre anywhere or anytime is annoying, but if you don't know how to fix it, it can be a scary predicament.
Not knowing how to get your wheel re-inflated and back on the road can make riding solo an un-nerving and ride limiting.
Even with a pair of the best road bike tyres, ideal gravel bike tyres or even best puncture-proof tyres, you can never guarantee against a flat wheel.
It's not just tyres either, take some time to get to know your rubber and Schrader vs presta valves in our guide on bike inner tubes (opens in new tab)which explains all about them.
However, with our guide for how to fix a puncture and mend an innertube, you'll soon be super confident in your own abilities to keep safe and get home from any bike ride.
We've explained the easy steps in the video above, and there's a picture guide that takes you through the steps underneath. However, as with everything in life, practice makes perfect. Once you've watched or read, make sure you spend some time having a go yourself.
Always make sure you try out your new skills at home in the warm and dry before setting off on your next adventure where the added elements of weather, light and time may be against you.
Step by step guide to fixing a puncture
Step 1: remove the wheel from the frame
Front wheel removal
Once you realise you have a flat, the first job for fixing a bike puncture is to remove the wheel.
It's a simple job of pulling down and unscrewing your quick release until you have enough slack to remove the wheel. If you are using Thru Axles, you'll need to either just unwind the leaver and remove the bolt entirely.
Some bike's don't have a tool free quick wheel release, so it's really important to check what system your bike is using. You might discover that it requires you to carry the correct size allen key for some Thru Axels
Some commuter bikes uses wheel nuts - if this is the case, you'll need a spanner - often 15mm - to loosen these off before you can remove the wheel.
If you have disc brakes you can simply pop the front wheel out and gently lower the bike down on it's forks.
If you are using rim brakes, you'll need to let off the brakes.
On caliper brakes, like the one above you can just lift the little leaver from down to up, which will slacken the cable to open the brakes enough to allow the wheel and tyre to come out.
If you have cantilever or V-brakes, as in the image above, you will just need to squeeze the brakes together and pop the cable out of it's housing, again to allow the brakes to open wide enough to allow the wheel and tyre to pass through.
Rear wheel removal
If it is a rear wheel puncture, you need to take all the above steps, but ensure you have adjusted the bike gears (opens in new tab) so that the chain is on the smallest chainring on the crankset and the smallest sprocket on the rear cassette. This makes rear wheel removal easier as the chain is at it's slackest.
Step 2: remove the valve cap and retaining nut
Take off the valve cap (the little piece of black plastic over the valve) and unscrew the valve retaining nut (the round ring siting against the rim) if there is one. Push the end of the valve to fully deflate the tube if it's not already empty of air.
Step 3: use tyre levers to loosen the tyre
Check the outside of the tyre for any clear causes of the puncture. If you see any debris stuck in the outside of the rubber, remove it and make a mental note of where it is in relation to the valve.
Bear in mind you might not find anything, but DON'T check by rubbing the palm of your hand on the tyre as it could be glass or metal, and the last thing you need when trying to repair a puncture is a cut on your hand!
Gently insert two tyre levers between the tyre and the wheel rim - directly opposite the valve (you can start anywhere but the further you are from the valve the easier it'll be).
Pull the tyre away from the rim using the tyre levers, one at a time. If you have three levers, hook the first two under the spokes and remove some more of the tyre with the third lever.
By now the tyre should be loose enough to simply run a tyre lever around the wheel rim to remove the rest of the tyre. With experience, you may only need one tyre lever.
It's worth noting here that this can be easier said than done, and that some tyres and wheel combinations are notoriously tight.
The ease to which a tyre pops of a wheel rim can also depend on the rubber compound. In general, the more robust a tyre, the harder it will be to remove.
The key here is to find the sweet spot of a tyre that you can remove, while limiting the chances of puncturing in the first place.
Ask around as most local riders will have their go to brands of tyres, as the kinds of roads and terrain will play a part in what works for your style of riding.
If in doubt, opt for a all/ four season tyre. This should be mailable enough to pop off the rim with a bit of encouragement, but will limit the risk of puncturing as much as possible.
Remember, if you can't remove it at home without assistance, you won't be able to remove it on your own out on the bike in all weather, times of the day and temperatures. So if you need to swop tyres, swop them!
Step 4: remove the tyre if you need too
Pull out the inner tube, and, if you need too, take the tyre off the wheel completely.
If the cause of the puncture was obvious, a thorn for example, you can probably leave one side of the tyre seated on the rim of the wheel, remove the object and then continue to the decision on new tube or or repair the tube below.
If it's not quite as clear why you have a bike puncture, then it's worth removing the tyre completely, as per step 5 below.
Step 5: check the tyre for debris
If the perpetrator is unclear, turn the tyre inside out and having a good inspection before attempting to insert another tube.
If there is a puddle close to hand, you could always re-inflate the old tube and submerge each section looking for the bubbles of escaping air to help locate the site of the puncture. You can then cross reference this to the tyre and focus on finding the cause.
Check that there are no further holes in your inner tube. Then carefully run your fingers around the inside of the tyre to check there is nothing else penetrating the tyre - if you find anything (small pieces of glass, thorns, gravel), remove it. Not doing so can result in the dreaded double puncture. It’s usually possible to make a visual check of the tread while doing this.
Step 6: decide on replace or repair
At this point you've got two choices - to mend the inner tube and replace it, or simply use a brand new one/ a pre-mended tube.
It's usually easier to use a new or pre-mended tube out on the road. This cuts the time of the roadside down and gets you back rolling as swiftly as possible.
We cover how to mend the punctured inner tube below for when you get home and can do an unrushed job.
Always ensure that the spare tubes you carry have a valve long enough for the depth of the wheels you are rolling on and a valve type that is compatible with one of the best bike pumps or best Co2 inflators (opens in new tab) that you should be carrying.
Step 7: put a little air in the tube
Inflate the (patched or replacement) inner tube slightly so it just becomes round in shape. This helps stop it pinching against the rim when you put it back in.
Step 7: refit the tyre on one side and insert the tube
If you did remove the tyre completely, it's now time to refit on one side. Make sure the tread is pointing the right way.
Some tyres have arrows on the sidewall indicating the ‘direction of travel’, other's are unidirectional and can be fitted in any direction.
Put the valve in the valve hole, and tuck the inner tube into the space between the tyre and the wheel rim.
Step 8: refit the tyre completely
When the inner tube is all in, ease the tyre back into place.
Starting at the valve, grip the rim of the wheel and push the tyre on to the rim, lifting at the same time to prevent the semi inflated tube getting pinched.
Try to finish directly across from the valve as the tyre will be looser there. If it gets difficult, let a little air out of the inner tube. Check there are no inner tube bulges from under the tyre, or that the tube isn't pinching under the tyre bead.
You can use tyre levers to help with the last section, where the tyre is tightest - but if possible avoid this as they can pinch the tube and cause you to have to start all over again.
The tougher and newer the tyre, the harder this will be - by contrast well used, supple summer tyres are usually much easier to get back on the rim.
Step 9: fully re-inflate the tube
Pump up the tyre to as close to the you ideal pressure, it's worth checking our guide to what's the correct road bike tyre pressure (opens in new tab) if you are unsure.
Ideally this would be done before you reinsert and refit the wheel into the bike securely, this just allows you to double check it's seated properly before full inflation.
If you are using a mini pump, you are unlikely to be able to inflate to full pressure, and even with CO2, you'll have to make a rough guestimate at the pressure. So be comfortable with getting the squish feel of your tyres at different pressures, so you can adjust your riding accordingly.
Once the wheel is back on the bike, close the brake quick release lever or reattach the brake cable if needed. If you have mended a rear wheel puncture, get someone to hold the bike up, and go through the gears. Check that the wheel spins freely and the brakes work correctly.
How to mend a punctured inner tube
Inner tubes can be quite expensive, and they're easy to fix so it's a good idea to mend them instead of simply replacing one and chucking the old rubber.
If the puncture is not obvious, pump up the inner tube. Once inflated, it is usually easy to hear the air escaping. If not, run the inner tube past your lips to sense the escaping air.
If you are still struggling to find the culprit, you can always submerge a re-inflated tube in a bucket or sink of water, and (like the puddle approach mentioned above) you should see the tell tale signs of bubbles where air is escaping.
Once located, roughen the area around the hole thoroughly with the emery paper in your puncture outfit.
Remove any excess emery or tyre dust and apply enough glue to cover an area a little bigger than the repair patch that you’ll use.
Do this a couple of times, allowing the glue to dry between applications. After the last application of glue, take a patch, remove the backing, and stick it on the inner tube. Press it home, working from the centre outwards. When you are confident that the glue is dry, carefully remove any further film attached to the patch.
There are patches that are self adhesive, which negates the glue faff so if you're time poor, these do speed things up a little, and are also a good option for a road side repair emergency.
How do I know what inner tube I need?
What are the different tubes and valve types?
In general there are two types of valve, Presta and Shrader Valve.
A Shrader valve is the same as you’ll find on a car tyre and to inflate it you simply have to use a pump with a compatible adapter. To deflate it you have to push a little pin found inside the valve.
Presta valves are thinner with a small captive nut found near the top. To inflate you need to unscrew the captive nut fully before using a pump with a suitable adapter. To deflate you unscrew the captive nut, then push it ‘in’ towards the base of the valve.
There are several different types of tubes on the market, which vary in material, rubber or latex for example, or in puncture protection level.
Check your spare tubes have the correct valves and that they're long enough for your rims. People often upgrade wheels to deep section rims, but forget to get new spare tubes with longer valves.
Finally, also check you have a compatible pump or inflator. Most will cater for both presta valves and shrader valves, but it's better to be safe than sorry.
We mentioned it above, but do check out our guide on bike inner tubes (opens in new tab) to help you navigate to the correct choice for you.
Why do I keep getting punctures?
How can I stop getting flat tyres on the bike?
If you find you're getting regular punctures, it's a good idea to check your tyres are still in good condition and appropriate for the type of riding you're doing.
Choice of tyres is almost as important as the wheels or frame. First of all your tyres need to be the correct size to fit your wheels. They need to be pumped up the appropriate pressure, as mentioned above.
Too much pressure could blow the tyre off the rim and too low a pressure will allow pinch punctures and tyre wall, or rim damage.
It’s also best if they are the right tread for the surface that you are riding on, the time of year and what riding you'll be doing.
Tyres that are smooth because they are worn out are useless and dangerous. Tyres that have a series of tiny cracks in the sidewalls or between the tread blocks need replacing too.
From time to time, a tyre may have some internal damage which results in a bulge somewhere around its circumference; this is another occasion when the only remedy is a new tyre.
Finally, the inner tube: make sure any replacement inner tube is the right size for the tyre, and you have the right type of valve to fit through the hole in the wheel rim. See below for valve types.
Can you fix a ripped tyre?
Can I ride a bike tyre with a hole in it?
If the hole in the tyre is large, this may cause the inner tube to bulge through the gap, like a hernia. If this is the case, replacing the tube will just result in another puncture.
The solution is to reinforce the hole, with an old piece of tyre from the inside. In desperate situations we have even seen energy gel wrappers used for this purpose. This solution is an emergency fix however, and should only be used to get you home or to your nearest bike shop.
Don't ride on determined to hit your mileage target only to get more stranded when the tyre completely fails.
Things to carry on any ride
- Tyre levers
- Two (or more!) spare inner tubes
- Patches/repair kit
- Some bits of old tyre to reinforce big holes
- A pump
- A mobile phone: if all else fails, get a lift home before hypothermia sets in
Hannah is Cycling Weekly’s longest-serving tech writer, having started with the magazine back in 2011. She has covered all things technical for both print and digital over multiple seasons representing CW at spring Classics, and Grand Tours and all races in between.
Hannah was a successful road and track racer herself, competing in UCI races all over Europe as well as in China, Pakistan and New Zealand.
For fun, she's ridden LEJOG unaided, a lap of Majorca in a day, won a 24-hour mountain bike race and tackled famous mountain passes in the French Alps, Pyrenees, Dolomites and Himalayas.
She lives just outside the Peak District National Park near Manchester UK with her partner, daughter and a small but beautifully formed bike collection.
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