There are few things more frustrating than a tire that won’t inflate. Oftentimes, new riders will see there’s no damage but the tire continually leaks air instead. While it’s a common problem, it’s also easy to fix.
So, why won’t your bike tires inflate?
The most common reason for a bicycle tires to not inflate when pumped, is an improper connection between the pump and the tire valve. Make sure you are using the correct type of pump (i.e. Presta or Schrader), and ensure a straight and firm connection. If this doesn’t work, then you should inspect the tire valve.
With that said, let’s dive right in. We’ll cover:
5 Reasons Your Bike Tire Won’t Inflate
You’ll need to know what’s going on before you can fix the problem. The following are five common reasons that a bike tire won’t inflate.
1. Pump Not Attached Properly
If you’re new to using a bike pump (or just haven’t used one in a while), then you may have it in the wrong position.
Bike pumps and valves can be a little bit finnicky, and you’ll need to make sure you have a clean connection in order for the airflow to work like it’s supposed to.
When the pump isn’t in line properly, it just results in backpressure in the pump and the release of air around the stem. You’ll notice that it’s very hard to pump and the tire probably won’t be receiving any airflow.
Solution: If this seems to be your problem, jump to this section below for more information about connecting your pump properly.
2. Presta Valve Not Open
If you have a Presta valve, then you’ll need to make sure it’s open before you can fill the tire. Opening a Presta valve is very simple, but if you’re new to them, it’s an easy step to forget. I use Presta valves, here’s what they look like (in the open position) on my bike:
Solution: You can tell if you have a Presta valve by looking at the air inlet for the tire. Presta valves will have a metallic stem with another round screw in the top, twist it left to open the valve. Once closed the tire won’t accept air.
3. Valve Stem is Pushed In
Schrader valves release air when the central pin is pushed down against the spring. Sometimes the spring can get pinned, causing the tire to continuously release air.
Remove the cap and check the valve. I’ve seen things as simple as a small piece of debris clamp a valve down and cause it to release air.
Solution: Just clear any obstructions and make sure the central part of the valve returns to the top of the motion. This is the reason you should make sure you have caps on your valves when you’re not inflating them.
4. Broken Schrader Valve
Valves sometimes break over time. It’s rare on a bicycle to see a tube last that long, but you never know what might happen. There are a few critical components that can cause failure.
Solution: For a bicycle, the best answer is usually just to replace the inner tube.
Alternatively, if you have an extra valve around, you can replace the core. You’ll just need a valve tool. Oftentimes they’re even built into the caps, look for a slotted top instead of the normal round cap. You can just screw in the functioning valve with the same tool once you’ve removed the broken one.
5. Torn Inner Tube
Inner tubes can be fragile, and any serious damage to one will result in a tire that doesn’t inflate. Small tears can lead to slow leaks as well, keeping your tire from staying inflated no matter how much you try to up the pressure.
If all else fails, check the tube for holes. The easiest way is just to inflate it outside of the tire and listen. Even a pinhole leak will often hiss. If you don’t find anything, another helpful trick, is to put it in water (e.g. a sink or bucket) and look for bubbles.
A leak that prevents the tire form inflating at all is rare, but it will be immediately noticeable.
Solution: for small tears, simply use a patch kit to repair the tube. For bigger tears (too big for a patch) you’ll need to replace the inner tube.
Double Check Your Pump (Most Common Issue)
The most common reason for a bike tire not to inflate, is a bad connection between the pump and the tire valve.
So, let’s quickly cover how you can fix this problem (and avoid it in the future). If you already know you have a different problem, then you can skip down to the next section.
Your pump should indicate whether or not it’s open. You need to have it firmly on the tire and then force the lever into position.
You’ll also need to make sure you’re using the correct pump for your bike (i.e. a Presta pump for a Presta valve or a Schrader pump for a Schrader valve).
Most good bike pumps have an adapter for both Schrader and Presta valves, but some will only allow you to fill one type of tire. If you have a pump with two openings, then the bigger hole is for Schrader tires and the smaller one is for Presta tires.
Press the pump down firmly over the stem with the correct hole. The lever then has to be flipped to allow air to pass into the tire. Most will flip upwards to lock the valve open and allow air to pass.
You’ll also need to make sure the pump is working. Just pump it while holding a finger over the air outlet, if you feel it building pressure then the problem is elsewhere.
If at first you don’t get a good connection, reposition the pump and try again. If, after a couple of tries, it’s still not working, then you probably have a broken pump or a broken tire valve.
Try to test this theory by borrowing a different pump (to see if your pump is the problem) or pumping a different tire (to see if your tire valve is the problem). Then, replace the faulty equipment.
How to Properly Inflate Bike Tires (with Videos)
A brief refresher on how to inflate both types of tire will likely be helpful in resolving your issue.
Inflating your tires can be a little more complicated than just pressing on the pump. It’s a simple process but some things are easy to overlook. Let’s get into it:
Schrader Valve Bike Tires
Schrader valves are very simple to fill, and they’re exceptionally common. They’re the same valve used in car tires for instance.
Just do the following:
- Remove the cap on the valve
- Press the end of the hose over the valve. If you have two outlets for different valves, the Schrader valve compatible side is the bigger one.
- Move the lever on the end of the hose. In most cases, it will end up in a parallel position to the stem.
- Pump the tire to the desired pressure, use either the gauge on the pump or a tire gauge.
- Move the lever back to it’s original position and remove the hose.
- Put the cap back on to avoid debris getting into the valve on your next ride.
Presta Valve Bike Tires
Presta valves are often found on high-end tires and they’re a little bit more complex to fill.
- Remove the cap from the stem, revealing the valve.
- Open the Presta valve by spinning it to the left. Press on the top to see if it’s releasing air, if so then you’re good to go for filling the tire.
- Place the pump’s nozzle over the valve, then lock the lever into position.
- Fill the tire until you’re at the right pressure for your riding.
- Press the lever down and remove the nozzle from the tire stem.
- Close the Presta valve by twisting it clockwise, press on the top to make sure no air is released.
- Replace the cover on the bike stem.
Why Won’t My Tubeless Tires Inflate?
When a tubeless tire doesn’t fill, the problem is basically always an air leak. Finding it is simple, as long as you go about searching in a systematic way.
Tubeless tires cause a different variety of problems than the standard fare. They seal into the rim after inflation using a compatible rim. They’re mostly used by MTB riders who want to lower tire pressure for better traction while avoiding the potential of a pinch flat.
The most common cause for tubeless setups not filling is that the tire isn’t fitted properly. If the bead isn’t set against the rim correctly, there’s no seal. Remember that tubeless tires require the whole system to be air-tight, so there are different places to check than when you use a standard bicycle tire with an inner tube.
- If you didn’t apply enough sealant to the tire then it may not have completely sealed to the internal portion of the rim.
- Check the nut on the valve. It should be completely hand-tight. A loose valve nut is often a point of failure for inflating your tires.
- If you hand-filled the tire when applying the sealant we have some bad news for you… rapid inflation of the tire is a requirement to get them sealed. Use an air compressor and try again with the sealant.
- Dents on the rim can create pinholes that allow air out. Check the rim for any damage if the above doesn’t work out.
If all else fails, spray the tire down with soapy water and then try filling it. The bubbles formed will be a dead giveaway to the source of your problem.