Knowing how to pump bike tyres is an excellent skill to have when it comes to cycle maintenance, but this begs the question ‘why do we need to pump our tyres’? Cycling on under inflated tyres makes the tyre rubber “stick” to the road and slows you down. This could be an advantage on muddy terrain as the larger surface area provides a bigger footprint to keep you stable, however, on smooth roads and trials it slows you down and can cause you to topple over. Also, it ensures a comfortable ride. If there isn’t enough air in your tyres then you won’t be well-supported and your cycling will be uncomfortable. Finally, it helps to prolong the life of your tyres. When an underinflated tyre squashes down, it can cause the sidewalls to squash and wear prematurely.
How to pump bike tyres with a presta valve
Before you can pump your tyres you will need to check if your pump is set up for presta valves. Some pumps only have one hole that will take either valve, but only after moving the fittings inside. Learn how to pump up a presta valve in detail in one of our other articles.
To set up your pump to the presta valve you first need to unscrew the knurled nut surrounding the hole.
This should be hand tight and has a “normal” thread, that is, it unscrews anticlockwise, the same way as most things in everyday life, e.g. taps, jars. Once that is undone, you will be able to see a circular piece of rubber with a hole.
To remove it, first open the lever, and the rubber pad will lift up.
Grasp the rubber and slowly slide it out.
Now you can see that both ends have a hole, the one for Schrader is bigger and the one for Presta is smaller.
Inside the pump head there is one more piece, usually made out of plastic. Tip this out of the head.
One end has a pointy end (the valve-stem-depresser) and the other end is open.
Now take the plastic piece and put it into the pump head with the valve-stem-depresser going in first so that the open end is uppermost.
Put the rubber part in place with the smallest hole facing upwards and the larger hole against the open end of the plastic piece.
You can now refit the external knurled nut. Close the lever and push the rubber seal down.
Now screw on the external knurled nut. Don’t over tighten it, it just needs to be finger tight.
So your pump is ready, let’s move on to the presta valve itself.
First unscrew the brass washer and depress it a bit as it sometimes seizes especially if it hasn’t been used for a while.
Push the connector on as far as you can. This is important as if the pump isn’t connected properly then the air isn’t getting into the tube. At this point air might start escaping, but don’t worry about this.
If there is a lever on your pump, move it now so that the pump adapter grips the valve.
Now start pumping.
Many people find presta valves a source of frustration. This is because the brass screw at the end of the valve is very thin and relatively delicate. Removing the pump at an angle can cause the brass screw to bend or even break. If it does break or bend too much then the tube is useless.
Practise removing the pump adapter with a sharp downward movement and if it is a constant source of irritation then buy a pump that works better for you.
How to pump bike tyres with a schrader valve
Before you can pump your tyres you will need to check if your pump is set up for schrader valves. Some pumps only have one hole that will take either valve, but only after moving the fittings inside.
To set up your pump to the schrader valve you first need to unscrew the knurled nut surrounding the hole. This should be hand tight and has a “normal” thread, that is, it unscrews anticlockwise, the same way as most things in everyday life, e.g. taps, jars. Once that is undone, you will be able to see a circular piece of rubber with a hole. To remove it, first open the lever, and the rubber pad will lift up. Grasp the rubber and slowly slide it out. Now you can see that both ends have a hole, the one for Schrader is bigger and the one for Presta is smaller. Inside the pump head there is one more piece, usually made out of plastic. Tip this out of the head. One end has a pointy end (the valve-stem-depresser) and the other end is open.
Now take the plastic piece and put it into the pump head with the open end going in first so that the valve-stem-depresser is uppermost.
Put the rubber part in place with the larger hole facing upwards and the smaller hole against the open end of the plastic piece.
You can now refit the external knurled nut. Close the lever and push the rubber seal down. Now screw on the external knurled nut. Don’t over tighten it, it just needs to be finger tight.
Your pump is now ready, let’s move on to the schrader valve itself.
Push the connector on as far as you can. This is important as if the pump isn’t connected properly then the air isn’t getting into the tube. At this point air might start escaping, but don’t worry about this. If there is a lever on your pump, move it now so that the pump adapter grips the valve. This should stop any air escaping. Now start pumping. If the air isn’t going in, you will find it really difficult to pump and the needle on the pressure gauge will be shooting up. Remove the connector and try again until the air goes in.
Now you can start inflating your tyre. Keep checking the pressure, either with the assistance of a gauge or by pressing on the tyre and feeling that it is “hard like an apple not soft like an orange”.
Once you have reached the desired pressure, release the pump and refit the dust cap.
How to pump bike tyres FAQs
If you need to pump up your tyres it is either because you haven’t inflated them for a long time or because you have a puncture. If you do have a puncture then tyre inflation alone won’t solve the problem.
There’s no hard and fast rule about this. If you use your bike daily, say to commute, then you should check them once a week. If you use your bike less frequently, then get into the habit of checking them before a ride. Air is being lost constantly, but at a very slow rate, so it is easy to not realise that the tyres are deflating.
1. To allow the air to enter the inner tube. The valve is where the air gets into the inner tube. It has a mechanism that allows air in and then can close to stop air escaping.
2. To allow the air to leave the inner tube. Sometimes we need to release the air from the inner tube. We might need to fit a new tyre, reseat the current tyre or allow the tyre past the brake blocks’.
A valve is used to control the amount of air in an inner tube. When the cylinder in a bicycle pump is compressed, air is pushed down the tube of the pump and then into the inner tube via the valve, which is forced open by the pressure of the air. When the handle of the pump is pulled up again, the valve shuts off automatically so that the air cannot escape from the tire, and new air is sucked into the cylinder so the process can be repeated. On top of the valve there should be a dust cap. This is designed to keep debris out of the valve. Standard issue are plastic, generally black, but different coloured plastic or aluminium ones are available. BMX riders will sometimes pimp their ride with funky shaped dust caps, such as skulls or dice.
Throughout the history of the bicycle, different valves have been developed and subsequently fallen out of use. Now there are two main types of valve, Schrader and Presta.
Schrader valve– The Schrader valve consists of a 8mm diameter stem into which a valve core is threaded. The valve core is assisted by a spring, this is called a check valve that is meant to allow airflow in only one direction; the Schrader-valve tube requires pressure on the inner pin to let air in. If the valve core is faulty, it can be extracted and replaced using a Schrader valve core tool.
Presta valve– The Presta valve is stem is 6mm in diameter. There are different lengths to allow for rims with a deeper section. 40mm is a standard length. Just the action of the air pressure holds the inner valve body shut, but there is also a small screw and captive nut on top of the valve body that ensures that the valve stays closed. To permit airflow in either direction, the valve nut must be unscrewed and depressed.
Advantages of a schrader valve:
The valve is more robust because the valve core pin is inside the valve, so can’t bend.
Because the valve has a larger diameter than a presta valve you can use a replacement tube with either valve.
Advantages of a Presta valve:
They require a smaller hole in the rim, which improves rim strength.
They seal tightly on air pressure alone, so there’s no need for a mechanical check valve like on Schrader systems (which can clog with debris).
There are a number of different pumps around, some suitable for bicycle tyres, some not.
Pumps suitable for bicycle tyres
Portable pump- The portable pumps need to be small and light enough to carry while you are on a ride, but designed so that they still work efficiently.
Track pump- Track pumps put air into the tube with less effort than a hand pump. As a rule they are too big to carry on a ride.
CO2 cartridges- These are very small canisters filled with pressurised carbon dioxide gas. Because they are so little they are easy to store. You can only use them once then the can has to be thrown away so not very eco-friendly.
Compressor designed for bicycles- This is very useful, especially for inflating tubeless tyres for the first time. It is quite an expensive piece of kit and normally found in bike shops.
Pumps not suitable for bicycle tyres
Shock pump- You may have a pump that is used to increase the pressure in your shock unit. It is light and small, but designed to put air in a very small chamber with very high pressure. It would be very difficult to reach the desired volume in a bike tyre.
Car garage pump– It is not a good idea to use a car garage pump as they are not very accurate and they are designed to put a large volume of air into a car tyre quickly. The trigger is hard to control and it is very easy to blow the tyre off the rim or for the inner tube to explode
When you are inflating a tyre, the amount of air that you put in is measured by how much pressure is pushing against the tyre and is rated by the following units:
-P.S.I. or pounds per square inch.
-kPa or kilopascal
You will find this information etched in small writing on the edge or sidewall of the tyre. The most common unit in the UK is PSI (pounds per square inch.) It will be expressed as a range, for example 50-80 PSI. The range allows for different situations, the most important being rider weight and terrain.
Start by being roughly in the middle of the range and adapt it from there to suit you. For example if you are carrying heavy loads, then run higher pressure
If the tyre pressure is too low:
- You can get pinch punctures. This is when the deflated tyre squashes against the rim and nips the tube.
- The ride can feel sluggish. This is because more tyre surface is touching the road causing rolling resistance
If the tyre pressure is too high:
- Cycling will feel very harsh. There will be very little give in the tyre and the ride can be very uncomfortable.
- It can cause a tyre blowout. A massive over inflation will likely result in the inner tube bursting and the tyre being forced off the rim.
Now let’s pump the tyre to the correct pressure. The easiest way is to buy a pump that has a gauge built in so that you can not only check the pressure but also pump the tyre to achieve the correct pressure.
If you don’t have a pump with a gauge, pinch the side walls of your tyre to get the best indication of how much air is needed. If it’s ‘Soft like an orange’ then the pressure is most likely too low and you need more air in the tyre. Pump in air and keep checking until it’s hard ‘like an apple’.
Overview of how to pump bike tyres
It is a good idea to check the air pressure in your tyres once a week because air is continuously being lost through the rubber of the inner tube, pumping your tyres should be much easier now you know how to pump bike tyres properly. If you are losing air more quickly than it could be a slow puncture and you may need to seek further help.