Why does my bike tire keep going flat? The Causes and Solutions

Biking comes with a lot of different problems from time to time. But one of the most distressing ones is when your bike tire keeps going flat, especially if it happens while you are out on the bike with no way to fix it!

I know exactly how it feels as I’ve had my fair share of flats on my bike even when there weren’t any punctures.

So let’s face it…

Bike tire flats are a common problem point for bike riders of all levels. Experienced bikers know how to fix this issue and what could be possible causes. But the same can’t be said for beginners and less experienced riders.

In this post, I’ll go over all the reasons why it happens and possible solutions to solve it since you most likely experienced this issue yourself or are currently dealing with a flat right now. 

Let’s jump straight into the causes:

Why does my bike tire keep going flat? 

The reason your bike tire keeps going flat is as a result of one of the following:

  • Punctures
  • Damaged Valve Stem
  • Overinflation of the tire
  • Low Tire Pressure
  • Rim Damage
  • Inner Tube Pinch
  • Impacts from Road/Trail Hazards
  • Tire Burping
  • Tire Failure/Wear

Any of the above reasons can cause your bike tire to keep going flat.

Punctures

Punctures are one of the most common reasons why your bike tire goes flat and keeps going flat.

How can you tell if your bike tire is punctured?

Whenever you have a punctured tire, you first have to remove the source of the puncture. The culprit in most cases will be a screw, nail, pin, glass, or some other sharp object. The easiest way to identify if your tire is punctured is by overinflating your tire and then spraying it with a mixture of dish soap and water.

Once you’ve sprayed the tire, look for any area where you see bubbles rising consistently.

What can you do to fix a punctured bike tire?

To fix a punctured tire, you first have to remove the object that has caused it.

If there is nothing inside your tire, you can identify the leak in your tube and then patch the puncture with an adhesive rubber repair kit or replace the tube altogether.

Damaged Valve Stem

Having a damaged valve stem means that the tire will keep going flat. This is because whenever you inflate the tire, air escapes out of the damaged section in your valve stem. This will prevent your tire from keeping the air inside it.

How can you tell if your valve stem is damaged?

To verify whether your valve stem is damaged, you can:

  • Inflate the tire and listen or feel if air escapes out of the valve stem.
  • Check for flaws in your valve stem by looking at it or using a flashlight, or in a brightly lit area. You will be able to tell that there is an issue after noticing obvious defects on the valve stem. You can also cross-reference the look of the quality of the stem with the valve stem on the other wheel.
  • Use the soap and water method to check for leaks.

What can you do to fix a damaged valve stem?

Your options for repairing a damaged valve stem are highly dependent on the type of bicycle valve stem you have on your bike. The two most common types are the Schrader Valve or Presta valve which we compared here. Both stem types require different solutions, so knowing which type you have is important.

If you have a Schrader valve stem, the most likely culprit for a leak will be the valve core since Schrader valves are well protected. In that case, you will only need to replace the valve cores.

If you have a Presta valve stem that is damaged, it’s a lot easier to replace your tube. However, if it’s the core that is the issue, you can simply have the core replaced and solve your problem of the tire constantly going flat. 

Overinflation of the tire

If you’ve ever had your tire deflated instantly after putting air in it, then it’s likely that you overinflated the tire and experienced a blowout.

How can you tell if your bike tire is overinflated?

The most straightforward way you can tell that your tire is overinflated or went flat due to a blowout is if it happens suddenly. You’ll also be able to feel that the bike tire is completely rigid.

If you’re not sure if your bike tire is overinflated, you can check the pressure by squeezing it with your thumb and index finger. If you can’t squeeze it at all due to how hard it is, you most likely inflated it too much.

This overinflation will put you at risk for a tube blowout, so you will want to deflate the tire a little, so there is a little give when you squeeze it.

What can you do to fix an overinflated tire?

The fix for an overinflated tire is simple if the tube hasn’t been damaged. All you need to do is reduce the air pressure in the tire.

Bike Rim Damage

A damaged rim is one of the more serious reasons why your bike tire is constantly going flat.

How can you tell if your bike rim is damaged?

Knowing if your rim is damaged is also very straightforward. It can be done by inspecting the rim, spokes, and nipples for damages. You can also do a soap and water test to see if you have a leaky bike rim.

Why would your bike rim be damaged?

Your bike rim most likely got damaged due to some impact while you were riding. It might also be damaged if you didn’t have enough air pressure in the tire to cushion the rim under impacts.

What can you do to fix a damaged rim?

The best way to fix a damaged bike rim is to have it replaced. However, fixing the damaged area of the rim is actually far more costly than just buying matching wheels. So I highly recommend just swapping them out.

Bike Inner Tube Pinch

A Bike inner tube pinch occurs when a bike tire becomes flat, and the tube shifts under the rim and gets pinched. Or it may happen when you hit a sharp edge or pothole hard enough that the tube gets pinched.

How can you tell if your inner tube is pinched?

To check if your inner tube is pinched, you must first remove the tube from the wheel. You will then be able to quickly identify the pinch on the tube because the pinch will be in the form of a snakebite pattern. In other words, you will see two holes side by side on your tube.

What can you do to fix a pinched inner tube?

Fixing a pinched inner tube first starts with prevention. You want to ensure that your tires are always properly inflated so when you hit potholes or other sharp road surfaces, your tire doesn’t get pinched again.

After prevention, the solution to resolving an already pinched tube is by using thin tube patches. Or you can simply opt to replace the tube.

Impacts from Road/Trail Hazards

How can you tell if impacts from road hazards damage your bicycle tire?

Impacts from environmental hazards will most likely cause damage to your tire, tube(pinch flat), or tire valve. In any of these cases, you will almost instantly notice that you have suffered damage to your tire.

What can you do to fix a tired that is damaged by a road hazard?

The solution to fix a damaged tire that keeps going soft because of damage from trail hazards depends on the cause. So refer to the solutions given in the previous sections if you can identify which area of your tire is leaking after taking the damage.

Bicycle Tire Burping

A tire burp is a small release of air that happens when a tire is distorted momentarily.

How can you tell if you are suffering from tire burping?

Tire burping normally releases a good deal of the air in a tubeless tire. You will be able to tell that it happens by the type of stunt you performed, latex marks on the tire, or how fast the air is released. You will also hear the sound of air being released or a pop sound.

What can you do to fix a tire burping?

To fix tire burping, the best solutions are to put more air in the tires. You can also try using thicker pure latex on the bead before inflating the tire. Or you can go back to using tubes.

Tire Failure/Wear

Overworn tires and tire failures are among the most obvious reasons why your tire keeps losing air pressure.

How can you tell if you have a tire failure?

You will be able to tell that your tires are bad by looking for cracks and excessive wear. Moreover, you will notice that the tire isn’t holding air or losing air pressure faster than usual.

What can you do to fix a tire failure?

The best solution to fix a failing bicycle tire is to replace it.

The Bottom Line: Reduce the Frequency or Stop your Tires from going Flat

There’s no one way to prevent your tires from going flat occasionally, as it’s a part of cycling that will always happen. However, you can keep an extra tube with you when you are doing long rides. You can also keep a few valve cores and tube patches just in case you end up needing them.

There isn’t much you do for tubeless tires or damaged rims except having a good bike pump available to reinflate your tires.

For punctured tires, you’ll need to find and remove the object that is causing your bike tire to go flat.

Lastly, if you’re not sure what’s wrong with your bike tire, it may be best to take it into a shop before continuing with any longer rides.