This may be a basic thing, but being able to pump the tires of a bicycle is a basic skill for any cyclist.
Many of you already know how to do this, but for those who don’t know, the different valve types, pumps, and more importantly, the pressure to inflate the tires can be a little overwhelming. Let us guide you through the process.
Pumping up the tires is a quick job and can easily improve your riding pleasure. Running the wrong tire pressure can have a negative impact on the way your bike rides and may also make your bike more susceptible to punctures.
If you have never repaired a puncture before, you may not have considered how to keep the air inside the tire.
Most bicycles will use inner tubes. This is an airtight tube in the shape of a doughnut, located inside the tire, with a valve for pumping it in, which you can see from the outside.
When the tire is inflated by the tube, it will cling to the ground and provide puncture protection.
You may have heard of tubeless tires, which abandon inner tubes and use special rims and tires to seal the air without inner tubes. These usually require an internal tubeless sealant, this liquid will block any point where the air escapes.
Tubeless tires are more common in mountain bikes, but the technology is migrating to road bikes.
Tubeless sealant can also block perforations, and the absence of an inner tube means that the risk of flattening is much lower-that is, when your inner tube is squeezed by the rim, it will cause a perforation. Therefore, tubeless tires can run at lower pressures than tube tires to improve comfort, speed and traction.
At the very high end, you can also get tubular tires. This is essentially a tire with an inner tube, but they are rarely seen or used outside of professional competitions.
Running tires at too high or too low pressures can be potentially dangerous and negatively affect the handling of the bicycle.
We will discuss what is the right pressure later, but now let us look at the possible problems.
If you run the tires at too low a pressure, the tires may wear out prematurely. Excessive bending of the sidewall can cause the tire casing to crack and the tire to become brittle. This may eventually lead to a blowout.
Too low pressure will also increase your sensitivity to punctures, and may even cause your tires to roll off the rim when turning at high speeds (internal pressure is the reason for fixing the tire on the rim).
If the tire is deflected all the way down to the rim, it will also cause damage. This can cause dents or cracks, which can damage your wheels and cause expensive replacements.
Conversely, excessive pressure may cause your tires to blow out of the rim, which can have explosive consequences. This pressure will also squeeze the wheel, because if the pressure is too high, the pressure on the wheel may be too high.
In terms of handling, low pressure will cause tires to creep under load, thereby affecting handling. Your bike will feel uncontrollable, slow and sluggish.
On the other hand, too high pressure will result in reduced grip and unsatisfactory riding, resulting in fatigue, which in turn affects handling.
There are two possible causes for a flat tire. Either you have been punctured, or your tire has just deflated over time.
Glue-free patches are great for quick repairs, and when you have more time, a more traditional kit is a versatile option.
All tire systems will slowly leak air because the inner tube is not completely sealed. For example, compared with lightweight latex tubing, standard butyl rubber tubing can hold air well, and the latter leaks relatively quickly. Even the tubeless device will slowly leak air.
Old pipes will leak more air than new pipes, so if your pipes have not been replaced in a while, they may be worth a look. It is unlikely, but it is also possible (especially on old pipes) that the valve no longer seals properly.
The best way to check what’s going on is to try to pump up the tires. If it keeps the air, then you may not need to do more. If not, then you may have a puncture.
If it leaks slowly overnight, either your puncture speed is slow, or it’s just an old tube that needs to be replaced.
The valve is a key component to keep the air in the tire, and it also allows you to inflate (or deflate) the tire.
Schrader valves are more common on low-end bicycles and mountain bikes of the past. The same valve is also used on car tires.
The valve assembly is a hollow tube with a spring valve that can be automatically closed and screwed into the external valve body. The pin extends upward from the valve, usually flush with the end of the outer tube. This pin can be pressed to expel air.
The dust cover on the Schrader valve is an important part of the design. If the valve is not completely sealed, it can help to completely seal the valve. It essentially provides a secondary “backup” seal.
The spring design of the valve is somewhat susceptible to contamination by dust or grit, so it is also important to protect it.
They originated from road bikes, where narrower valves (6mm vs. 8mm for Schrader) mean that there are smaller valve holes on narrow road wheels (usually the weakest part of the rim).
Today, they can be seen on mountain bikes and road bikes. Instead of using a spring, the valve is fixed with a nut to keep the valve closed, although the valve itself will “automatically” seal when the pressure inside the tire closes it.
For Schrader valves, you only need to press the pin to release the air, but for Presta valves, you must first unscrew the small lock nut. Don’t worry about the nut falling off the end of the valve body, because the thread is knocked to prevent this from happening.
There seems to be a saying that Presta valves can handle high pressures better-considering that Schrader valves can withstand hundreds of psi (much more pressure than your tires need), this may not be true.
However, the Presta valve is definitely more refined than the Schrader valve. It is very easy to strike the threaded internal valve body and bend or break it, so you need to be careful. However, the spool is easily replaced with standard tools.
Presta valves may have a locking ring to secure the valve body to the rim. This can make them easier to inflate. The dust cap is not necessary to seal it, but it helps to keep the valve clean.
The only other type of valve you may encounter is the Dunlop (also known as Woods) valve. Its bottom diameter is similar to that of the Schrader valve, but it can be inflated with the same pump accessories as the Presta valve.
These are very popular in towns/stand-up bikes in Europe and other parts of the world, but you are unlikely to encounter this type of bike in the UK or the US.
The valve of the tubeless device is directly connected to the rim, rather than part of the tube.
If you have a Schrader type valve as shown in the picture above, then the first thing you need to do is to remove the dust cap (if any).
Inflate the tire to a value between the minimum and maximum specified on the tire sidewall, and then remove the pump. You are done!
If your bicycle has such a Presta valve, you must first remove the plastic valve cover (if installed).
Now connect the head of the pump of your choice to the open valve and inflate the tire to a pressure between the minimum and maximum specified on the tire sidewall.
If you are using a tubeless device, or a tube device with a sealant inside, it is worth taking some extra steps to avoid clogging of the pump.
Turn the wheel so that the valve is at the bottom and leave it for a few minutes so that any sealant can drain.
Turn the wheel so that the valve is at the top, and then inflate the tire. This is also true when deflating the tires to prevent mucus from being sprayed everywhere.
We would say that if you can only have one type of pump, buy a domestic crawler pump because it is efficient, fast and easy to use.
However, there is no doubt that using an extra mini pump when you are on the road is very useful-otherwise you might get stuck on the side of the road if you get punctured.
We already have a guide to help you choose the best bicycle pump for your needs, but here are some suggestions for you to consider.
There are no limits for crawler pumps. They basically all do the same job, and some feel more advanced than others.
From the affordable Park Tool PFP8 to the extremely expensive Silca Pista Plus, you can always find a product that suits your needs.
Post time: Sep-16-2021
