The reason you keep puncturing your MTB tires

Tire punctures always happen at the worst of times in mountain biking, and can even get quite dangerous leaving you hanging with no traction.

Even worse is when there is no way to repair or swap the tire. Then the ride is over and the walk home is long.

double flat tire dh bike
As rare as double rainbows, but not as enjoyable: double flat tires.
One was a snakebite, the other a puncture by a pointy rock.

There are ways to minimize the risk of flatting your tire. Let’s quickly cover what leads to punctures so we can eliminate them:

  1. Pinch flat (or snakebites): When the tire and tube are pinched between the ground and the rim.
  2. Puncture: When sharp or pointy objects puncture through the tire tread or sidewall and the tube.
  3. Small leaks: When vavle is leaking, the rubber of the tire or tube gets brittle and starts tearing or the rim is damaged.
  4. Tire burping: On tubeless tires only, burping happens when the tire bead is pulled off from the rim momentarily, releasing air.

The pinch flat and puncture flat are by far the most common ones in mountain biking. And they are easily avoided with the correct preparation.

Correct tire pressures

Check tire pressures before every ride

Bike tires lose air over time – some quicker, some slower. But it pays to check your pressures before every ride. Don’t leave handling and flat protection up to chance.

Don’t run tire pressures too low

Low tire pressures are by far the most common reason for flat tires in MTB. It’s the cause of pinch flats, punctures and burped tires.

In MTB you want lower pressures to allow the tire to conform to the ground and really dig in to generate traction where the terrain offers little. But running it too low has two issues:

  • The sidewalls get pushed out, making them prone to sidewall slashes.
  • The rim can pinch the tire or tube resulting in pinch flats.
  • And the tire bead sits looser on the rim so it can be pulled off by aggressive cornering (burping).
low tire pressure, sidewalls puched out
Low tire pressure pushes the sidewalls out and brings the rim closer to the ground.
maxxis tire pinch flat
With enough force and low enough pressure, the tire and tube are pinched between rim and ground.
burped tire leaking tubeless sealant
Burped tire leaking tubeless sealant.

Don’t run tire pressures too high either

The reason is that a tire needs to conform to the ground in order to generate traction and absorb bumps.

High tire pressures take away the ability of the tire to conform over sharp edges. Instead, it’s easy to get penetrated.

if you put 50 psi in your tire you're gonna have a bad time

Use strong tire casings

Protective rubber matters.

If you ride aggressively with heavy hits, save yourself time, money, and your patience by going for a heavy-duty tire casing – at least in the rear of your bike.

Due to the higher weight and harsher impacts the rear tire has to endure, punctures are more frequent there.

Maxxis EXO Protection
Maxxis “EXO Protection” label.
Maxxis Exo Protection Explained
EXO+ double protection: bead-to-bead layer and sidewall insert

There are basics of puncture protection in MTB casings are as follows:

  • None (only found in XC tires)
  • Thicker nylon threads for the casing (60TPI)
  • Double layered casings (like Maxxis Double Down)
  • Sidewall protection only for snake bites (pinch flats)
  • or a bead-to-bead layer under the tire tread against punctures.

More sidewall inserts means heavier tire weights. So pick accoding to your riding style.

For any more info, I explain MTB tire casings in detail here.

Use correct tire widths for the rim width

Similar to low pressure‚ a rim too narrow can also lead to bulging tires – that are vulnerable to side slashes.

stans notubes correct tire width
Stans NoTubes Wideright correct tire width. // Credit: Stans NoTubes

Line choice on the trail

Here’s an innovative tip to not get your tires slashed by sharp edges: Don’t ride over them.

But on a serious note, better line choice out on the trail is a legit way to avoid punctures. You can pick a line, that you know your bike and tires can handle if you encounter an exceptionally rough bit of trail.

Pumping and jumping can help in making the bike lighter over pointy objects and dig into the ground when it’s softer.

This is of course a matter of skill and experience. The better you know a trail, the easier it is to look ahead and recognize trail features in advance.

A hardtail is obviously more puncture-prone than a full-suspension bike due to the lacking ability to absorb impacts through suspension travel. Hardtails need to be ridden at different speeds or on different lines than a fully.

Replace old, brittle tires

It’s no secret that rubber in any form will get brittle over time. Even if the tire tread is still good, your old tire might be showing signs of giving up.

On my trail bike, I ran a tire for close to 4 years. The tire wear was still okay, but it was so brittle that it did not keep air for long and sealant leaked out all the time.

old brittle tubeless tire leaking sealant
Notice the dark, wet spots in the middle of the tread where tire sealant is coming through the tiny holes of this old tire.

Old tires are one reason for the slowly leaking flat tires or overnight flats. The same can happen with rubber tubes and valve cores.

Replace brittle tubes and old valves

If you feel like your tires are losing air too fast (overnight) it could be down to another issue: The valve stem and tube connection for tube tires or the valve stem and rim interface on tubeless tires.

Tube tire:

A very common area where tubes get damaged over time is the seal between the tube and valve stem.

It’s the frailest part of the entire tube. Like any seam, the seam between the tube and the valve stem is fragile and inclined to start leaking air from the tiniest hole.

Again, the older it gets the more prone it is to getting tears and holes by itself.


Just give it a shake and put your ear close to the valve. If anything is loose, you could actually hear more air come out.

In the case of air exiting from the valve area, check by tightening that lock nut from where you’re losing your air from.

This may include checking on the valve core too. I had a very sudden change in how well my front wheel could hold air. It wasn’t the nut at the interface of the valve to the rim, it was that the valve core itself was loose.

Switch to tubeless tires with tire sealant

One top hack to eliminate all pinch flats forever is to actually not use tubes anymore and swap to tubeless. And it’s actually easy to do, especially if you already know how to change a tire yourself.

Tire sealant is one of the main benefits of tubeless tires as it manages to keep air in your tires with minimal pressure loss. The other benefits are of course lower tire pressures and lower weight.

tubeless ready tire sign
This or a similar label is required for tubeless tires.
stans notube sealant and valve core
A Tubeless-specific valve is also required.
Tubeless tire sealant is optional but highly recommended to automatically seal small punctures.

Use tire inserts with tubeless tires

MTB tire inserts are similar to tire mousse used in motocross: hard foam is installed in tubeless tires. They allow for lower pressures and more traction by reducing air volume and protecting the rim and tire.

If you manage to still puncture the tire, the tire insert will help keep the tire not completely folding. That allows you to safely ride down the rest of the trail without needing an immediate repair stop.

For long enduro rides with technical descents, where mechanical problems can’t so easily be fixed and spares are scarce, one insert in the rear tire may be an option.

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Julian Mat is a former bike shop owner and editor of Suspension Traveler. He has been riding Downhill MTB and Enduro for over two decades.
Julian has poured all his accumulated knowledge, best-kept secrets, and proven guides into Suspension Traveler, to make it the go-to resource for gravity mountain bikers.

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