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 because there may be more.
2. Remove the 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 rimBikeRadar
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 sideBikeRadar
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. Locate the puncture on the inner tube
Inflate the punctured tube and rotate it around close to your face to find the holeBikeRadar
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.
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 adhesionBikeRadar
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 gluing. Thoroughly brush off any rubber ‘shavings’.
If you’re using glueless patches, you can apply them directly after cleaning the area around the holeBikeRadar
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.
Once the glue has dried to a matt finish, apply the patchAmanda Thomas
The key to ensuring a good repair is patience, so don’t rush this step.
5. Patching an inner tube
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 tubeAmanda Thomas
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. Inspect the tyre casing and rim tape
Thoroughly check the casing of the tyre for any other debris that may cause another punctureAmanda Thomas
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 holesBikeRadar
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. Refit the tyre
After repairing the tube and thoroughly checking the tyre, reﬁt one bead to the rim.
Slightly inﬂate the tube and reﬁt it to the wheel, putting the valve through its hole first.
Push the tyre bead back onto the rim with your thumbs, taking care not to pinch the tubeBikeRadar
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. Check the repair
‘Massage’ the tyre into the well of the rim, ensuring the tube isn’t being pinched by the bead of the tyreAmanda Thomas
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 wheelBikeRadar
Inﬂate the tyre to a point where it feels soft but has maintained its shape then check that the molding 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.
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 gently to roughen the tube by rubbing it against a stone or the road surface
How to identify a puncture
Regular or ‘point’ flats are caused by debris piercing the tread of the tyreBikeRadar
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 too, with the rotation of the wheel slowly driving it into your tyre.
Pinch flats are most often caused by running too low a pressure in your tyresBikeRadar
Two small holes in a tube placed fairly close together indicate 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.
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 enjoying the view an opportunity to be relished or an unwanted distraction?
Park’s GP-2 patches are our favourite optionBikeRadar
For those that want pre glued patches, Park’s GP-2 patches are our favorite.
It’s hard to find fault with Nutrak’s super-simple repair kitBikeRadar
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 sexyVelo Vitality
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 grouptestBikeRadar
Believe it or not, not all tyre levers are made equal.
You should never leave home without a mini pump!BikeRadar
While a mini pump is a great option if you’re out on the road, do yourself a favor 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.
Jack has been riding and fettling bikes for his whole life. Always in search of the hippest new niche in cycling, Jack is a self-confessed gravel dork, fixie-botherer, tandem-evangelist, hill-climbing try hard, and thinks nothing of taking on a daft challenge for the BikeRadar YouTube channel. With a near encyclopaedic knowledge of cycling tech — from the most esoteric niche nonsense to the most cutting edge modern kit — Jack takes pride in his ability to seek out tech and stories that would otherwise go unreported. Jack has been at BikeRadar for three years now and is currently testing an All-City Mr Pink as his long term test bike.