Presta Valves and Schrader valves are the 2 main air inflation valves used at present especially on bicycles. This article is a good place to start with for those who have recently started riding bicycles as we will give you a overview of each type of valve, there advantages and key differences.
What is a Presta Valve
Presta valves are also known as the French valves are widely used in road side or mountain bicycles where tyres are highly pressurised. It is also called the Sclaverand valve after the name of the person who invented it.
These valves are widely popular and are often compared to the Schrader valves. However, the Presta valves are generally easier to pump than the Schrader valves as these do not have any spring to overcome. The Presta valves are also known to allow high air pressure and require a much smaller rim hole as compared to the other valves.
You will usually find these valves on the high-performance bikes out there because of the fact that they are capable of holding very high air pressures as compared to most of the other similar devices on the market. You will also find these valves on the mid as well as high-end mountain bicycles particularly if these bikes are manufactured in a tubeless condition by the manufacturer.
History of Presta Valve
Sclaverand invented the Presta valve back in the time while he was working for a France based company named Morin. This company later merged with another company called Pourait in 1935; to eventually turn into the widely famous company we are all familiar with, namely Zefal. The precise information regarding the year of the invention of Presta valve is still missing. However, based on the other incidents around that time, it is speculated that the first ever Presta valve supposedly came into existence in a year somewhere in between 1880 and 1890.
Key Features of a Presta Valve
The Presta Valves consists of a valve stem on the outer side and a valve body on the inside. There exists a lock nut that is meant to secure the valve stem at the rim of the wheel. There might also be a valve cap in addition.
The valve rim consists of a hole specifically included for the valve stem. Presta valves usually have very small holes that make them capable to accommodate very narrow wheels alongside providing and maintaining adequate strength in the wheels.
The valve body remains shut due to the air pressure in the inflated tires. Additional support is provided by the captive nut and a small screw present on the crown of the valve body. They also serve the purpose of keeping the valve tightly shut. When unscrewed, air is permitted to flow in either direction. It is to be kept in mind that the unscrewing has to be done before the pump is attached.
The valve cap is another important element that ensures that the valve body is protected and is bereft of any dirt or mud as these impurities can hinder the mechanism of the valve. It also keeps the tube damage free when rolled for storage purpose.
Average Size of a Presta Valve
The Presta valves are available in wide range of sizes. However, the average size of the external threads of a Presta valve is usually around 5mm2 which approximately the same size as that of a Dunlop valve. The valve stem is found in a variety of lengths so as to cater to the different applications. For example, the valve stem usually has a diameter narrower than Dunlop valves and Schrader valves.
Adaptors in Presta Valves
An average Presta valve consists of a thread on the exterior. An adaptor fitted to this external thread to connect the Presta valve to a Schrader chuck. This adaptor may also come into use while converting a Schrader pump to something that is flexible enough to be connected to adaptors of other types.
Advantages of Presta Valves
Below, we have mentioned some notable advantages provided by the Presta valves at present.
Easy to Use
Presta valves do not come with any valve spring that needs to overcome. For this reason, the process of inflation using a hand pump becomes extremely simple.
Easy to maintain
There are detachable valve cores in virtually every Presta valve which has been set up tubeless. This implies that once the core becomes bad, it will be feasible for you to replace it with a fresh one. Apart from this, in case the whole valve becomes useless, the nut on the valve shaft can simply be unscrewed and the entire thing can be swapped within a few minutes.
More powerful wheels
It is a fact that the Presta valve comes with a small diameter, and because of this, the hole which is drilled into the wheel happens to quite small as well. In this way, the narrow wheels are able to maintain adequate strength in the long run.
Reduce chance of sticky valves
The design of the Presta valve does not include any valve spring, and because of this, your sealant does not need much for gumming up.
Several stem lengths
In case you would like to go for a lengthier valve stem, you will not be disappointed given that Presta valves are available in lengths that vary from 30 mm to 60 mm.
What is a Schrader Valve
The Schrader Valve is also called American Valve. It was invented in 1891 by August Schrader. The original design of this valve was patented in 1893 in United States. There are many reasons for which this amazing value is used.
Uses of Schrader Value
It is used in many motorcycle tyres and vehicle tyres. Apart from being used in many tubeless and tube tyres it is also used in many air conditioning systems as well as refrigeration system. Due the mechanism it works on it is also used in various fire extinguishers. It is also used in aircraft to maintain the high-pressure hydraulic systems.
Dimension of these values
With Schrader valves being used in so many applications you will come across various sized valves. To help organise the sizes a Classification system has been produced. Classification is based on diameter, material, shape and length of the valve. Below is a extract from the classification chart:
TR- 4 — 8 mm diameter Straight metal stem
TR- 6 — 8 mm diameter Straight metal stem
TR – 87 —10 mm diameter Short 90 degree metal stem
Advantages of Schrader Valves
Here, we’ll be listing the advantages of Schrader valves;
Ease of use
Compared to the Presta valve or other kinds of valves, the Schrader valve is the easiest to use. Almost all of the automobiles apart from specific bicycles have the Schrader valve attached to their tires. All you have to do is un-screw the cap to deflate or inflate your tire. The spring inside the Valve ensures that the air supply is consistent and doesn’t change.
Schrader valves are far more durable than other valves that are being sold in the market today. Since the Schrader valves have a special system in place that makes it the perfect valve since the system has a spring that enables easier and consistent air inflation. Since these can take rough handling, you’ll see that all kinds of automobiles; from high end cars to an uber cab. The Valve is very durable.
Spares always available
The Schrader valves have a spring system that makes it easier for one to fill and remove air from the vehicle. Since it can handle a lot of rough use, there is hardly any chance of the tire or tube going bad. On occasions when the valve goes bad, it’s very easy to find spares for the Schrader valves.
Easy to Use
The Schrader valves have a simple mechanism in place to inflate your tire. While the hand pumps need a depressor to fill in air quickly, you can easily get the air filled at a gas station or fill it in with an old electrical pump.
The Schrader valves come in varying diameters and can be used for varied purposes apart from being the best and most used valve for vehicles. The Schrader valve is used in many refrigerators and air conditioning units. The Schrader valves are used in these appliances for servicing purposes. This includes recharging refrigerant and coolants. Due to its sturdy build and intricate engineering, the Schrader valve becomes the top choice for heavy vehicles as well.
Differences Between Schrader And Presta Valves?
It is quite tough to pump Presta valves thanks to its compact diameter which needs a more compact-sized hole in the rim. These valves are typically used on the thinner road bike tires since they are more slender and entail a thinner hole in the rim. In fact, the weakest component of the rim happens to be the valve hole and therefore, the smaller the hole the better.
Virtually all the Presta valves come with a detachable core which can be recognized by a couple of wrench flats on the uneven valve cap threads. The main advantage of this is that there is no need to replace the tube once the Presta nut comes off and makes way for injecting sealant into the Presta tubes.
It is quite simple to use Schrader valves thanks to the presence of the spring closure since the inflation chuck only needs to be pressed onto them at any auto service station. The valve depressor is provided by a screwed chuck when it comes to hand pumps.
Apart from making the inflation process simpler, the depressor is also required for reading backpressure within the tyre. This valve happens to be bombproof and is going to deliver the goods on most occasions.
Presta valves have the ability to adjust to a higher pressure as compared to the Schrader. Even though the majority of the road bike tires are going to exceed 125 lbs. The Schrader tubes will top out at approximately half that. In case your tube comes with Presta valves, you will require a specially manufactured pressure gauge intended only for Presta valves.
A Schrader valves diameter is 8 mm which is more than that of a Presta valve at just 6 mm. It is easier to work with this type of valve, unlike a Presta valve. You simply need to take out the cap from the Schrader and apply the pump head thus ensuring that it is positioned far enough so that there is no air leakage whatsoever.
Thus it is clear from the above discussion that both Presta valves, as well as Schrader valves, come with their own pros and cons. You simply need to go for the one that matches your requirements.
Over the years, the Presta valves have become immensely popular and useful especially for mountain rides.
The Schrader valve has recently experienced competition with the Presta valve when it comes to mountain bikes and high-end riding bikes. There has been constant debate about which valve is better than the other for bicycles. It all depends on the types of tyre the bicycle has.
The higher-end mountain bikes tend to have a thinner tyre. This means that the tube of the tyre is going to be thin too and the rim of the tyre will not be wide enough to accommodate a hole for the Schrader valve. The presta works wonders in this case. But for heavy-duty vehicles and bicycles, there is nothing better than the Schrader valve.