Why is My Bke Presta Valve not Inflating?

It has been a long week, and you were hoping to enjoy the weekend by going for a morning ride through the lakes and hilly roads. You start off your day very early, but after riding for a brief period, you suddenly notice a lot of resistance riding.

You pull up for a little check-up and then end up seeing that your tires are inflating. So, you ask your buddy if he has a pump with a Presta valve adapter. He gives you the Presta valve adapter, but your tires are not simply inflating even after using the pump.

This is somewhat of a technical issue because your Presta valve is not inflating. The reasons can be complex or very straightforward. Either way, since you are facing difficulties, I am here to assist you. 

How many types of Valves are there

Presta valve not inflating

There are mainly two types of valves: the Schrader Valve and The Presta Valve. Let us talk about them so that you a few things about these things. 

Schrader Valve

The most easy-to-use valve out of the two, the Schrader valve’s pumping is as uncomplicated as it gets. The process is simple just attach your pump to the valve with a tight lock with the lever then just start pumping.

You just have to put out the pump once you’re done pumping and the front tube of the valve will automatically be placed as it was.

Schrader Valve usually releases a bit of air when you’re pulling out the pump and it generally deflates faster than tires with a Presta Valve.

The Schrader valves are usually wider than Presta valves in terms of size. It is most likely seen that Schrader valves are in most of the cheaper bikes and also on car tires. 

Presta Valve

The more complicated of the two is to inflate a Presta valve, first, open up the top nut places placed above the stalk. This top nut screw holds the air pressure. Then press the stalk with a little nudge then you are good to go for attaching the pump.

Typically place your pump locking with the lever. Presta Valve is more airtight than Schrader valves because the air pressure itself is blocking the path of air coming out.

Presta Valves are used in bikes that are in the premium segment like the racing bikes. 

Benefits of the Presta valve

Presta Valves are simply better than Schrader valves because of how accurate the air pumping can be.

Usually, mountain bikers aren’t necessarily bothered about the air pressure as the rough terrain doesn’t add much value to exact air pressure, and also you won’t really feel your tires are deflating unless a large margin does it.

Whereas, on the modern bikes that have thinner tires, you will more often than not ride your bike on flat surfaces and roads so you’ll notice your tires deflation when you sudden decline in speed or resistance while accelerating. 

Moreover, Presta Valves hold more air on the tires than Schrader valves. The air pressure itself in the top nut seals the air pressure. It is also lighter and gives proper wheel rotation than the heavier Schrader valves.

The drawback I see is the complicated process of pumping through Presta valves. Schrader valve pumping is more suitable for beginners. 

How to inflate tires with a Presta valve

Reasons why your tires are not inflating with a Presta valve

Before telling the reasons, I must clarify to you how to inflate the Presta valve because if you don’t know the proper way, then evidently, it won’t inflate.

With Adapter 

It’s a simple process. You will need an adapter that is incredibly tiny in size. 

  1. Firstly unscrew the top tip of the valve, then press to see if the air is coming out. 
  2. Then attach the pump and start pumping.
  3. Once the optimum amount of pumping is done, screw the top part of the valve, then press it again to see if the air is coming. This time air should not come out. 

Without Adapter 

This one is a tad bit complex and will require your proficiency. You will need scissors or a pocket knife for this part. 

  1. Firstly unscrew the valve cap, then remove it a
  2. Look for the tiniest section to cut off the part where you will require a knife or scissors. 
  3. Then attach the modified cap on the valve while the tire is upside down and screw just about when you could press the top cap to check the air pressure,
  4. Attach the pump and then start inflating to the optimum amount. 

5 Reasons Bike tires are not Inflating with a Presta Valve

1. Proper fit on the Pump

This is one of the most common issues of all. You must be careful to attach your pump to the valve perfectly. If you see that noise of air coming out when trying to pump then that is the cue.

Your pump is not fitted and it releases more air than it actually trying to intake.

Make sure you have adequately unscrewed the top tube. Cross-check by pressing on it because you will notice air pressure.

Place the pump firmly, and if you see no air noise, then it is likely you are now inflating your tires

2. Sealants causing a barrier 

Sealants can be a necessary tool for the tires that become vulnerable easily as it prevents the tire from puncturing. But, it also can be a problem because the liquid layer often creates a barrier for the air to get in on the tire through the valve.

The sealant becomes a barrier for the air to enter, and it’ll leave you to wonder about why you’re unable to inflate your tires. If you see that your valve is filled with sealant, then open up the value and thoroughly clean it.

No amount of sealant should be there. Be careful in handling the valve and its parts since those are minuscule and can get lost easily. 

3. Using the wrong pump

Not using the right pump is also one of the fundamental issues. You may be trying to push air with a not suitable pump for Presta Valves.

There are various valves in the market. Some are for Presta valves, some are for Schrader valves, and while some pumps are universal.

So, be sure to know which pump exactly you are using. You could be complaining about your tires and the valves but when in reality the issue is in your pump. 

4. Tire puncture

A punctured tire can also be followed as one of the fundamental issues. You could have a long day of riding through bumpy terrain, and your tires have been pinched by something pointy.

Clearly, you may be unaware of it, which is why you are confused over why your Presta valve is not inflating the tires. So, be sure to check if your tires are punctured or not.

Find the parts where the tires are punctured, then apply sealants. Sealants will block the path from where the air is getting out.  

5. Broken Valve Stem

This comes down as a last resort, I feel. If you see that your air pull-out noise is coming even after perfectly placing the pump, then you have to realize that your valve stem is probably broken.

The key should be replaced with the tube with a new one. The tube will come with a new valve stem and make sure you match the same valve in accordance with the sizing of your tire.

FAQs (Frequently Asked Questions) 

Should you keep Presta Valve adapters with you

Presta Valve adapters are tiny in size and can easily be lost. So, it is wiser to purchase a bunch of them as it is pretty cheap. All types of maintenance and bike shops have Presta valve adapters available. 

How can you check the tire pressure of your mountain bike?

There are two ways. One is the traditional method which is through your hands, and another is through a tire pressure gauge. Through your hands, hold the center of your tire, and you should notice that it is supposed to stay hard, but it can be somewhat confusing because it can depend on the force you are applying.

However, a tire pressure gauge is known to show accurate information. 

Does Mountain bike tires have Presta valves?

Only the high-end premium ones have Presta valves installed in them. Mountain bikes are thicker and broader tires, so it is more suitable for Schrader valves. Presta Valves are common among sporty bikes or on-road bikes because they have thinner tires.

The high-end mountain bikes now have Presta valves because of their resistance and build quality.

A Presta valve in general provides more service as its air pressure resistance is more than Schrader valves. It also gives proper rotation than Schrader valves.

Can my tires be completely deflated without getting punctured?

Yes, it can, but only if the bike has been unused for an extended period of time. Often unused cycles deflate on their own. The air escapes on its own once you want to start riding it again. 

Why isn’t the Presta valve adapter not working? 

It can maybe because you have pressed the top screw enough or the screw hasn’t been unscrewed enough. You also need to be careful in screwing the adapter fully then, it should entirely suck in the air.

Another reason can be if the diameter of the adapter isn’t compatible with the valve or the top screw is a bit long for the adapter to fit in. 

Wrap Up! 

Thus, I believe now you are well informed about what to do when Presta Valves are not inflating your tires. I have explained to you many reasons. Some reasons can be quite complex to pull off, while most of them are pretty effortless to partake.

Also, before telling you the reasons, I have told you how you should inflate the tires through your Presta valve with and without the adapter so that you have complete clarity over the concepts.

I think you are good to go whenever this issue arises since I know you are an avid cycle enthusiast, and you enjoy learning about bikes.

You can even share your insights with your cycle enthusiast friends and colleagues since it is a niche and an interesting subject. 

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