How to repair a puncture

Beginners step-by-step guide to patching an inner tube

Knowing how to repair a puncture is an essential skill that every cyclist needs to master. It can be daunting for the inexperienced, but only takes a few minutes once you know what you're doing.

In the following guide and videos below, we'll talk you though how to repair a punctured inner tube on either a road or mountain bike in a simple, step-by-step walk-through guide.

We talk you through how to repair a puncture on a mountain bike
The process for fixing a puncture on a road bike can be slightly different

1. How to find the puncture

Using the valve as your starting point, closely inspect the tread of the tyre to find the cause of the puncture. Also pay attention to the sidewalls (the non treaded portion on the side of the tyre) to make sure there are no tears or holes. 

Remove any glass, grit or other debris that you spot. 

Even if you find one possible cause, continue checking the tyre until you get back to the valve as there may be more. 

2. How to remove an inner tube

Let the air out of the inner tube and push the valve up into the tyre, unscrewing and retaining the valve lockring if fitted. 

Use a second lever, roughly 5cm away from the first, to begin to pop the bead off the rim
Use a second lever, roughly 5cm away from the first, to begin to pop the bead off the rim

On the side of the wheel opposite the valve, slip a tyre lever under the tyre’s bead and a further tyre lever, about roughly 5cm away. 

Run the lever around the tyre to free one side
Run the lever around the tyre to free one side

Pull the nearer tyre lever towards you, lifting the tyre’s bead over the edge of the rim. Continue until one bead of the tyre is completely free of the rim then pull the tube out. 

Remove the tyre completely from the rim — with most tyres this can be done by hand unless exceptionally tight.

3. How to find the puncture on an inner tube

Inflate the punctured tube and rotate it around close to your face to find the hole
Inflate the punctured tube and rotate it around close to your face to find the hole

Inflate the tube and listen for air escaping. If you're struggling to find the hole by listening alone, try passing your lips over the top of the tube. 

If the hole still can't be found, re-inflate the tube and pass it through a bowl of water until you spot escaping bubbles. Be sure to dry the tube before proceeding to the next step.

4. How to prepare an inner tube for patching

Select an appropriately sized patch — if in doubt, err on the side of caution and use a bigger rather than smaller patch.

Sand down the area around the hole to aid adhesion
Sand down the area around the hole to aid adhesion

Roughen the surface of the tube around the hole with sandpaper (usually included with any good puncture repair kit).

Ensure that any moulding marks on the tube are completely flattened down as these can cause issues when glueing. Thoroughly brush off any rubber 'shavings'. 

If you're using glueless patches, you can apply them directly after cleaning the area around the hole
If you're using glueless patches, you can apply them directly after cleaning the area around the hole

If you're using pre-glued patches — such as Park's GP-2 patch kit — you can now patch the hole. Thoroughly press down on the patch to ensure it's fully in contact with the tube.

If you're using a 'traditional' glue-on patch kit, start by applying a generous drop of glue — or rubber cement by its proper name — to the tube and spread this across an area slightly larger than the patch you intend to use. Allow to dry. 

Apply a second, thinner layer similarly. Once again, allow to dry — when the glue is dry it will change from shiny to matt.

The key to ensuring a good repair is patience, so don't rush this step.

5. How to patch an inner tube

Once the glue has dried to a matt finish, apply the patch
Once the glue has dried to a matt finish, apply the patch

Firmly press the patch into place after removing the backing foil — cleanliness is also key to a good repair, so leave this to the very last moment. 

Make sure the whole of the patch is in contact with the tube
Make sure the whole of the patch is in contact with the tube

If there’s a thin cellophane backing on the patch, it can be left on. It's good practice to dust any stray glue with chalk, talcum powder or fine road dust to prevent it from sticking to the tyre casing.

6. Check the casing of the tyre and rim tape

Thoroughly check the casing of the tyre for any other debris that may cause another puncture
Thoroughly check the casing of the tyre for any other debris that may cause another puncture

Before refitting the tube, thoroughly double-triple-check the inside of the tyre casing — there's nothing more frustrating than going to the effort of patching a tube only to puncture it again with a stray thorn you may have missed.

Make sure your rim tape is secure and covering all spoke holes
Make sure your rim tape is secure and covering all spoke holes

It's also good practice to check the rim tape. If a hard plastic rim strip — often found on cheaper bikes — is torn, it leaves a sharp edge that can easily slice a tube. Likewise, if your rim tape has slipped, it can leave eyelets or spoke holes exposed, which can also puncture a tube. 

If you have persistent problems with your rim tape puncturing your tube, try swapping it out for a roll of good ol' Velox cloth tape or similar. This stuff lasts forever, costs very little and can be reused if you're so inclined.

7. How to refit the tyre

After repairing the tube and thoroughly checking the tyre, re-fit one bead to the rim. 

Push the tyre bead back onto the rim with your thumbs, taking care not to pinch the tube
Push the tyre bead back onto the rim with your thumbs, taking care not to pinch the tube

Slightly inflate the tube and re-fit it to the wheel, putting the valve through its hole first. 

Starting at the opposite side of the rim to the valve, use your thumbs to lift the tyre’s bead over the rim. Work your way around the rim until there’s just one small section of tyre left. 

Push the valve up into the tyre and then, using your thumbs, ease the remaining section of the tyre’s bead over the edge of the rim.

If the tyre is particularly tight, avoid the temptation to use a tyre lever to push the last section of the tyre onto the rim — you'll almost certainly pinch your inner tube doing so. 

If you're struggling to pop the tyre onto the wheel, try putting the tyre on the ground, holding it in place with your feet and rolling the the bead back towards you — heavy gloves really help here. This takes a little practice, but should work with even the most stubborn tyres. 

8. Make final checks

'Massage' the tyre into the well of the rim, ensuring the tube isn't being pinched by the bead of the tyre
'Massage' the tyre into the well of the rim, ensuring the tube isn't being pinched by the bead of the tyre

Check that the tube isn't trapped between the rim and the tyre bead by working your way around the tyre, pushing the bead into the well of the rim.

If the tube is trapped, try 'massaging' the tyre to encourage it to seat properly. Pumping it up a small amount may also help to seat the tube properly. 

Inflate the tyre, ensuring that it is seated evenly around the wheel
Inflate the tyre, ensuring that it is seated evenly around the wheel

Inflate the tyre to a point where it feels soft but has maintained its shape then check that the moulding mark around the tyre follows the rim evenly all the way around.

If not, deflate a little and ease any high spots down and pull low spots up until the bead is fitted evenly.

Inflate to the recommended pressure and check once again that the tyre’s bead is still seated evenly and that the tyre isn't lifting off the rim at any point, then adjust your pressures to suit. 

Fixing a puncture: useful tips

  • When taking the tube out of the tyre, note which way the tube was around in the wheel. This will help identify the position of the hole in the tube once the position of the object in the tyre causing the puncture has been found
  • Once you've located the hole in your puncture, mark it with a piece of chalk (usually included with a repair kit) so you can pinpoint it accurately later
  • If you don't have any sandpaper, you can try to gently roughen the tube by rubbing it against a stone or the road surface

How to identify a puncture

'Regular' puncture

Regular or 'point' flats are caused by debris piercing the tread of the tyre
Regular or 'point' flats are caused by debris piercing the tread of the tyre

A 'regular' puncture is usually caused by debris — glass, thorns, wire, nails etc. — entering the tread of the tyre and piercing the inner tube. 

There's little you can do to avoid these types of puncture beyond opting for puncture resistant tyres — while effective, these are best saved for town or commuting bikes as they tend to weigh a lot more than regular tyres and really dampen the ride quality of a bike.

Those unfortunate enough to get punctures regularly may have noted that they tend to get more flats during wet weather. This is because surface water essentially acts as a lubricant, allowing anything sharp to enter the tyre more easily. 

Wet weather allows debris that would otherwise stay on the ground to stick to your tyre more easily, with the rotation of the wheel slowly driving it into your tyre. 

Snakebite punctures

Pinch flats are most often caused by running too low a pressure in your tyres
Pinch flats are most often caused by running too low a pressure in your tyres

Two small holes in a tube placed fairly close together indicates a pinch — or snakebite by its other name — puncture. This is caused by the tube getting trapped between the tyre and the rim when riding over a hard-edged object. 

Tyres that are not inflated enough are the most frequent cause of this. If you consistently get pinch flats, particularly on a mountain bike, it may be time to convert to tubeless.

If you have a pinch flat, be sure to check that the tyre’s sidewall isn't cut as well.

Rim tape or spoke puncture

A hole on the inner side of the tube indicates that the puncture was caused by something around the well of the rim, usually a rough edge on a spoke hole or torn rim tape if it is made of a hard material. 

Check around the inside of the rim to ensure that the rim tape properly covers the spoke holes and that all spoke holes are free of swarf — if you find any sharp edges, these can usually be filed down.

A less common cause of a puncture is a rough edge around the valve hole. A puncture here will occur at the base of the valve and will not be repairable.

What puncture repair kit should I buy?

The puncture-fixing brigade is divided into two distinct camps — those that insist on using an old-school, glue-on patch kit and those that prefer pre-glued patches. 

In our experience, glue-on patches are more reliable in the long run, but pre-glued patches are far, far more convenient. 

What you prefer to use will largely be down to personal preference and likely dictated by your temperament — is stopping for five minutes to fix a tube properly and enjoy the view an opportunity to be relished or an unwanted distraction?

Park's GP-2 patches are our favourite option
Park's GP-2 patches are our favourite option

For those that want pre glued patches, Park's GP-2 patches are our favourite.

It's hard to find fault with Nutrak's super simple repair kit
It's hard to find fault with Nutrak's super simple repair kit

For an old-school style patch kit, it's hard to beat the exceptionally cheap Nutrak P3 kit.

Yes, it's possible for a patch kit to be sexy
Yes, it's possible for a patch kit to be sexy

For those after a more Gucci patch kit — yes, such a thing exists — you can bring a bit of French charm to your saddle bag in the form of this handsome patch kit from Rustines.

Whichever patch kit you buy, if it comes with one of those nasty little multi-tools that feel as though they're made from cheese rather than metal, please put it into your nearest recycling point. Trust us when we say that they'll do more harm than good to your bike.

It's also a good idea to pack a pair of gloves with any repair kit. Braking surfaces, particularly rim brake tracks, will make an absolute mess of your hands and nobody wants to inadvertently grab a stray patch of dog poop with bare hands. 

What are the best tyre levers?

Pedro's tyre levers came out on top in our grouptest
Pedro's tyre levers came out on top in our grouptest

Believe it or not, not all tyre levers are made equal.

Thankfully, we've done the hard work for you, whittling down a selection of the most options out there, with Pedro's levers coming out on top.

What is the best pump?

You should never leave home without a mini pump!
You should never leave home without a mini pump!

While a mini pump is a great option if you're out on the road, do yourself a favour and get a decent track style pump for use at home — these take far less effort to use than a mini pump and will allow you to get your tyres up to much higher pressures.

Save yourself some serious hassle and invest in a decent track pump for use at home
Save yourself some serious hassle and invest in a decent track pump for use at home

We're working on a long overdue update to our best pumps guides, so check back soon!

Some riders prefer to use CO2 canisters over pumps
Some riders prefer to use CO2 canisters over pumps

If you prefer to take a CO2 inflator with you, check out our top 6 recommend options here;

Weekly check-up for tyres

Check your tyres for cuts in the tread, swelling in the sidewall, or serious wear. 

Tyres with severe cuts, swelling or casing visible through the tread must be replaced. Remove any grit or glass embedded in the tread with a fine pick. 

Regularly check your tyre pressures with a proper gauge. Tyres inflated to the correct tyre pressure will have fewer punctures and a longer life.

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