Why Do I Keep Getting Flats?

Flats have a cause, and most of them can be fixed

If you keep flatting, start with the setup. Our default recommendation today is tubeless with fresh sealant, a plug kit in your pocket for the holes sealant cannot close, and a tube along as the backup. If you still flat on that setup, the cause is usually the tire, your pressure, the road, where you are looking, a worn tread, or a bit of the last flat still stuck in the casing.

We first wrote this post in 2016, and it was written entirely around tubes. We rewrote it in October 2026 to match how we set bikes up at the lab now. The stories and habits from the original are still here, because they still hold.

Nobody likes the group ride flat

Flatting alone is bad, and flatting on a group ride is worse. If it is the kind of group that waits, everyone stands around while you work, and there is an unspoken "please hurry" hanging over the whole thing. If it is the kind that does not wait, you fix it alone and chase. The worst version is when you fix it, roll off, and flat again two miles later. Everything below is about not being the rider it keeps happening to.

Start with the setup

The biggest change since we first wrote this is tubeless. On a tubed tire, a thorn goes through the tire and then the tube, and the air leaves through the tube. On a tubeless tire there is no tube. The tire seals against the rim, and liquid sealant inside closes small holes as they happen, often before you notice. Zipp also points out that with no tube there are no pinch flats, which lets you run lower pressure.

Tubeless is not for everyone, and we wrote a whole post on who road tubeless suits and who it does not. For a rider who flats a lot on rough or dirty roads, it is where we start. This is how we think about the layers:

1. Sealant handles the small stuff. Keep it fresh, because sealant dries out inside the tire over time and a dry tire seals nothing. We stock sealant from Stan's, Orange Seal, Silca and Muc-Off in our tubeless sealant lineup.
2. A plug handles the hole that keeps hissing. You push it into the puncture with the wheel still on the bike, then spin the wheel to spread sealant over it.
3. A tube is the backup for a cut that is too big to plug. Carry one on every ride, tubeless or not.
4. A tire boot goes inside the casing when the cut is big enough that the tube would bulge through it.

Thru-axles and disc brakes change how the wheel comes out and goes back in, which we cover step by step in our roadside flat routine.

The tire still makes a difference

Some tires are built to be light and fast, and others are built to keep things out. If you are flatting a lot, you are probably on the first kind and riding roads that call for the second. Our rule of thumb has not changed since 2016: if you flat more than about once every ten rides, that is not bad luck, and it is time to look at your tires.

Puncture protection comes from what is under the tread. Continental, for example, puts breaker layers such as PolyX and Vectran under the tread, and other tire makers have their own versions. When you shop, look for that layer on the tire you are considering and match it to your roads. We carry tubeless ready road, gravel and mountain tires from Continental, Pirelli, Schwalbe, Maxxis, Panaracer, Challenge and Vittoria, and you can browse them in our tubeless tires collection.

Spend the money on a good tire.It costs less than a season of flats.

A correction from the old post

The 2016 version said Continental's "Black Chile Pepper" technology was what made its tires flat resistant. The name is BlackChili, and Continental describes it as a tread compound for grip, rolling resistance and mileage. The puncture protection comes from the breaker layers under it, not from the rubber.

Liners and inserts are a real option

The old post told you to skip tire liners. We do not say that anymore, because we install liners and inserts at the lab, and for the right rider they make a lot of sense. There are two kinds, and they go with different setups.

Liners for tube setups

A liner sits between the tire and the tube. Tannus says its Armour insert is designed to be used only with an inner tube, and that it protects the tube against punctures. It is a good fit for a rider who wants to stay on tubes, like a commuter, a kid's bike or an e-bike, and is tired of fixing them.

Inserts for tubeless

A tubeless insert sits inside the tire against the rim. CushCore says its inserts only work with tubeless setups, and that its profile reduces pinch flats by putting a soft barrier between the rim and the tire, while also supporting the sidewalls. CushCore makes versions for gravel and several kinds of mountain biking. We stock both Tannus and CushCore in our tire inserts collection, and fitting either one at the lab is billed bench work.

Your weight and pressure make a difference

A heavier rider puts more load on the tire. On a tubed setup, too little pressure lets the tire bottom out on the rim and squeeze the tube, which leaves the two little snake bite slits of a pinch flat. If you are a bigger rider on tubes, check your pressure before every ride and pick a tougher tire. On tubeless there is no tube to pinch, which takes that kind of flat off the table.

A real one

The road to the scrap yard

One of us flatted on a nice looking road right after mounting brand new tires, on a tire model that had not flatted in a very long time. The next week, on the same road with a different bike and different wheels, it happened again.

The rider alongside said he had flatted on that road a few times too, and he knew why. The road ran straight to the local metal recycling yard, trucks hauling scrap used it constantly, and bits of metal kept ending up on the shoulder. That road came off our route list for good.

If one road keeps biting you, the tires may not be the problem at all. Ask around, because somebody in your group may already know why.

Paying attention makes a difference

Watch the road in front of you. You will not see every flat coming, but you will see a lot of them. Do not be the rider who rolls through glass instead of checking traffic and moving around it, because that costs you and everyone behind you. If you are on the front of a paceline, it is your job to spot rocks, glass, trash and roadkill and point them out. Lead the group into a mess and you will lose more than air, because the group will stop trusting your wheel. We have all done it once, and the trick is not doing it twice.

Tire wear makes a difference

When you can see the threads of the casing through the rubber, the tire is done. The rubber is part of your flat protection and all of your grip, so once it is worn through anywhere, replace the tire. We really do have to say this one, because some riders are still trying to squeeze one more season out of a tire that gave up last summer.

You just got a flat. Find what caused it.

The most common cause of a second flat is the first one, because whatever got you is often still in the tire. On tubeless, the hiss and the spray of sealant usually show you the spot. On a tube, it takes a little detective work before the new tube goes in:

1. Note where the tube satAs you pull it out, keep track of how it lined up with the tire, valve to valve.
2. Find the hole in the tubePump a little air in if you need to, then listen or feel for it.
3. Match it to the tireLay the tube next to the tire in the same position, and you have the spot where the puncture happened.
4. Check the tire, inside and outLook for glass, wire or a small slit on the outside. Then sweep your fingers gently and slowly around the inside, because whatever went through the tire can go through your finger.
5. Dig it outUse the pick on your multi tool or anything small and pointed, which is one more reason to carry a multi tool.

If you skip that last step, the same tiny piece of wire will flat your new tube a mile down the road, and that one is very disheartening.

Set it up right. Fresh sealant, a plug kit and a backup tube cover most of what the road throws at you.

Then look at the rest. Check the tire, the pressure, the route, your eyes and the tread, and add a liner or an insert if your riding calls for one.

Fix the cause, not just the hole.

Tired of flatting?

And check that tire before you put the new tube in.