Presta valve cores follow the same universal structure. Some models are more sophisticated than others, but in most cases, the cores are interchangeable as they’re the same size and use identical threading.
Are All Presta Valve Cores Removable?
No, they’re not.
To determine if you have a Presta valve with a removable core, look at the valve stem.
If the core is removable, the valve will consist of two parts – upper and lower.
The upper part will be significantly shorter and will insert into the lower.
Sometimes, the stem and the valve core are of different colors. (E.g., the stem is gold, the upper portion is silver).
If the Presta valve has a unified body, then the core isn’t removable. In case of malfunction, you will have to replace the entire inner tube.
If you have a removable valve core, there are three main ways to replace it:
- By using a dedicated tool (best method)
- Via a spoke wrench #11.
- Via a set of needle-nose pliers
The image below shows a dedicated tool that grabs the core and allows you to unscrew it.
Alternatively, you could use a set of pliers or a spoke wrench #11.
The spoke wrench works just fine whereas the pliers increase the chance of damaging the valve.
If you plan to use Presta valves in the long term, it’s worth getting a specialized tool as it saves time, reduces risk, and facilitates the installation of a new valve core.
Why Should I Remove The Valve Core?
There are two main reasons to remove the valve core of a Presta valve – to replace it with a new one or to put sealant into a tubeless tire.
If you don’t remove the core when adding sealant, the process won’t be comfortable and efficient.
You will have to be continuously pressing the plug to keep the valve open. The plug will instantly become sticky, and the liquid reaching the tire will be insufficient. It’s just bad practice.
If you have a non-removable valve core, you will have to add sealant the old-fashioned way – by breaking the tire bead.
This may be fine if you’re trying tubeless to see how it feels, but if you intend to use the set-up for a long time, investing in a tube with a removable valve core will be very helpful.
What Are The Benefits Of Having a Removable Valve Core?
A removable valve core makes the valve serviceable. If the valve is malfunctioning, you can replace the core and continue using the tire.
Another benefit is the ease of adding sealant to tubeless tires.
Having said that, you are more likely to bin a tube due to numerous flats over time rather than a failed valve core.
In some cases, the core may be just as expensive as a new tube. Thus, a removable valve core is of lower benefit to people who aren’t running a tubeless set-up.
Can I Use a Cheap, Generic Valve Core For My Tubeless Set-up?
Yes. You don’t need a fancy valve core to go tubeless. It can be done with generic ones sold in a package.
Of course, a dedicated tubeless valve will look nicer as they come in different colors that can match your bike, but from a functionality standpoint, they don’t offer a must-have feature.
How Can I Insert Sealant Through a Presta Valve Without Making a Mess?
To avoid contamination when filling a tubeless tire with sealant, use an injector.
The injector is made of two main pieces – a hose and a syringe.
The hose attaches to the valve after removing the core and allows you to add sealant without having to break the tire’s bead.
Does The Size of a Presta Valve Matter?
Most Presta valves have the same diameter. However, the length could vary depending on the wheel on which they’re installed.
A deep-section wheel, for example, would need a longer Presta valve. Otherwise, the valve won’t “show on the surface”, and you won’t be able to pump the tire.
You don’t need a lot of the valve showing, though. If you can comfortably screw a pump on the valve, it’s long enough.
It’s advisable to stay away from super-long valves because their lengthy stems are easier to damage.
If the valves are too short for your particular rim, you can consider buying Presta valve extenders. As the name suggests, the purpose of those adaptors is to extend the valve.
There are two types of valve extenders – for removable and non-removable valve cores.
Extenders for removable valve cores are meant to be used as follows:
- Remove the original valve core.
- Attach the extender to the valve.
- Screw the core onto the extender.
Extenders for non-removable cores operate a bit differently:
- Unscrew the top part and leave the valve open.
- Screw the extender onto the valve.
Note: Some valve extenders come with o-rings creating an airtight space, but most do not. Thus, people wrap Teflon/plumber’s tape around the valve to make the connection airtight.
How Tight Should a Presta Valve Core Be?
There isn’t a specific “valve torque”. Just screw the valve core until it’s snug and secure. You don’t have to use a lot of strength. If the valve is still leaking, it’s time to replace it.
Can Presta Valves Be Used On a Schrader Rim?
A Presta tube can be used on a Schrader rim but only with a special adaptor known as Schrader – Presta grommet. I have a dedicated post on the topic. You can read it here.
Why Does My Presta Valve Core Keep Coming Out?
If the valve core is coming out, it’s probably not tight enough, or the threading is worn out.
If the core continues to bounce after screwing it with a tool, consider replacing it.
How Can I Remove Sealant From the Valve Cores?
If you get a sticky valve core due to sealant build-up, you can use a cleaner containing ammonia to remove the leftovers. (Ammonia is a solvent found in latex-based sealants.)
If you don’t have ammonia, you can use hot water and soap.
Unfortunately, in some cases, the valve core may be too contaminated and in need of replacement.
To avoid such problems, some riders put silicone or synthetic grease on the valve cores. A layer of grease around the threads acts as a shield preventing the sealant from sticking to the core.
The grease has another benefit too – it reduces the effort needed to get an airtight valve.
My Presta Valve Core Is Bent. Why? What Should I Do?
The valve core is fairly soft and delicate because it’s made of brass. If you don’t remove the pump vertically after usage, you can easily bend the core.
A slightly bent valve core is not necessarily an issue. If you can still close it, the valve should continue to operate normally.
If the core is notably bent, you can try to re-shape it gently. However, you shouldn’t perform this procedure continuously as you could easily break the core.
Should I Carry a Spare Valve Core with Me?
It’s not a bad idea, especially if you’re covering long distances.
If you decide to carry one in your saddlebag, put it in a hard plastic box. Otherwise, the other items in the bag may damage it.
That said, it’s not mandatory to have a back-up valve core when riding in urban settings, especially if you already have a spare inner tube with you.
In the case of valve core failure, you can replace the tube.
