Asked
Modified 4 years, 4 months ago
Viewed 52k times
I haven't used my bike for almost a year and I need to start riding it again, but it appears I have a flat tire. I don't think there's something wrong with the tube cause I haven't used it for a pretty long time. It just won't inflate. The tire has a Schrader Valve. I use a pretty old pump so maybe that's the case? I'm not really sure.. So is there any way I could inflate it again without getting a new tube or tire?
1
You can easily inflate a completely flat tire (provided the tube is still good). Usually, when a tire is completely flat, you have to press the back of the tire so that the valve doesn't recess into the tire so your pump can be attached properly to it.
With a presta valve, you can use your mouth for this (well, on a clean tube, since the valve stem isn't spring loaded), but with a schrader valve you have to use a pump.
If it still won't inflate, check the tire and tube for damage and replace accordingly.
3
Make sure the valve isn't stuck. If it's been sitting that long it probably is. Look at the valve and you'll see a pin in the middle. This pin needs to be depressed for the valve to open and allow air into the tube. Press down on it with a ball point pen, screwdriver tip or similar object to unstick it. Then follow the advice above about holding the tube in place while you attach the pump.
I had a similar problem and what worked for me was soaking the valve in white vinegar as you would a shower head for half an hr and then gently pushing the middle bit with an old ikea small allen key. worked perfectly.
ps i used a tissue soaked the tissue (cotton balls are better) in white vinegar, place them on the valve wrap in foil around tire and I let it sit for about an hr or 2)
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Required, but never shown
Required, but never shown
By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy
Asked
Modified 3 years, 4 months ago
Viewed 15k times
I got a new road bike with tubeless tires.
I can't get the back tire to hold air. I got the front tire inflated but for some reason, as I am pumping the air all I hear is it coming out somewhere from the tire. I don't see a hole. It was shipped from another state and it came completely flat.
3
There could be many causes for a flat tubeless tyre, especially on first installation.
If any of these conditions are not met, rectify the problem before trying again.
If they are all met, then you have a hole in the tyre - not at all unheard of in tubeless ready tyres which are designed for use with sealant.
To find the hole, get a helper to operate the pump for you, whilst you carefully inspect/listen to where the air is escaping.
Whilst still pumping (to generate some air pressure), rotate the wheel so the hole is at the bottom. This will cause the sealant to pool in that area and plug the hole.
1
Tubeless tyres hold air only after being seated properly. That means the bead is at the shoulder of the rim's flange.
Many tyres have to be inflated and under pressure to seal the bead. One has to inflate them with more air per second going in through the valve then getting lost along the yet unseated bead.
For many MTB tyre-rim combinations a workshop compressor or tubeless charger (pump with air tank) is necessary.
Since you were able to seat the front tyre with your pump the following might be enough: Push each bead as far on the shoulder as possible. Then pump very vigorously until you hear the beads pop into their place. This can be very loud. Also, a little sealant spread on the shoulders might help to increase the initial seal just enough.
4
Larger volume tubeless tyres need a good blast of air to get them seated, a track pump often won't get it done, especially if you've had a few tries and have got tired.
A compressor will do the trick but they're not always available, consider a tubeless inflator like an Airshot or the Bontrager FlashCharger.
When my tubeless tyres won't mount it can often be down to the tubeless rim tape. Once it gets wrinkled or dirty with sealant the tyre can't slide up to the rim quick enough. Try cleaning the rim tape and inner rim walls. If this fails I generally replace the rim tape with new and it works first time.
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Required, but never shown
Required, but never shown
By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy
Everything you need to know about pumps, valves, pressures and more
It may be elementary, but being able to inflate bike tires is an essential skill for any cyclist.
Many of you already know how to do this, but for those who don't, the different types of valves, pumps, and more importantly, how much pressure to inflate your tire can be a little overwhelming. Let us help you through this process.
Contents
Pneumatic tires were invented to overcome the harsh "ride quality" of massive wheels.
The air inside acts like a spring, giving you suspension and allowing the tire to adapt to the terrain for better traction.
Tire inflation is a quick job that can easily improve your driving pleasure. Incorrect tire pressure will adversely affect cycling and make it more prone to punctures.
If you've never repaired a puncture before, you may not have thought about how your tires hold air in.
The vast majority of bikes will use a tube. It's a donut-shaped airtight tube that sits inside the tire with the inflation valve you see on the outside.
Inflated tire rests on the ground and provides puncture protection.
You may have heard of tubeless tires which do not have a tube but use a special rim and tire to seal air without using a tube. This usually requires a tubeless sealant, which is a liquid that plugs any air outlets.
Tubeless tires are more commonly used on mountain bikes, but the technology is moving to road bikes.
Tubeless sealant also seals punctures, and no tube means much less risk of pinching flat surfaces - that's when your inner tube gets pinched by the rim, causing a puncture. Thus, tubeless tires can run at lower pressures than inner tube tires to improve comfort, speed, and traction.
At the highest level, you also get tubular tires. They are essentially a tire with a tube built into it, but they are rarely seen or used outside of professional racing.
Inflating tires to the correct pressure is an important part of bike maintenance.
Running tires at too high or too low pressure can be potentially dangerous and can also affect your bike's handling.
Later we will discuss the correct pressure, but for now let's look at possible problems.
An under-inflated tire will reduce your efficiency and leave you vulnerable to annoying punctures.
If you drive with tires at too low pressure, the tire may wear out prematurely. Excessive sidewall deflection can lead to carcass cracking and tire brittleness. This can eventually lead to tire blowout.
Excessively low pressure also increases your susceptibility to punctures and can even cause your tires to literally jump off the rim if you turn at speed (the pressure inside is what keeps your tire on the rim).
Damage can also be caused by tire deflection up to the rim. This can lead to dents or cracks, which can compromise your wheel and require a costly replacement.
Conversely, too high pressure can cause the tire to come off the rim with explosive consequences. This pressure can also compress the wheel because if it is too high, the compressive force on the wheel can be too great.
From a drivability point of view, low pressure can lead to poor drivability due to the tire squirming under load. Your bike will be difficult to control and will be slow and sluggish.
On the other hand, too much pressure can lead to poor traction and a rough ride, leading to fatigue and in turn poor handling.
There are two possible reasons for your flat tire. Either you have a puncture or your tire has deflated over time.
The adhesiveless patches are great for a quick fix, while the more traditional kit is a versatile option when you have a bit more time.
All tire systems will bleed slowly because the tubes are not completely sealed. For example, standard butyl tubing retains air fairly well compared to lightweight latex tubing, which bleeds relatively faster.
Even tubeless setups will slowly leak air.
Old tubes will pass more air than new ones, so if they haven't been replaced in a while, it's worth taking a look at them. It is less likely, but also possible (especially on older tubes), that the valve is no longer sealing properly.
The best way to check what's going on is to try pumping up the tire. If it's holding air, you probably have nothing else to do. If this does not happen, most likely you have a puncture.
If air leaks slowly overnight, you have a slow puncture or just an old tube that needs to be replaced.
The first thing you need to know before inflating a tire is the valve type.
The valve is the key part that keeps the air in the tire but also allows the tire to be inflated (or deflated).
The Schrader valve is also used for car tires.
Schrader valves are more common on lower end bikes and in the past mountain bikes.
The same valves are used on car tires.
The valve assembly is a hollow tube with a spring loaded valve that automatically closes and screws into the outer housing. The pin comes out of the valve and is usually flush with the end of the outer tube. This pin can be pressed to release air.
The dust cap on Schrader valves is an important part of the design that can help close the valve completely if it is not fully sealed. Essentially, it provides a secondary "backup" seal.
The spring-loaded design of the valve is slightly susceptible to contamination from dirt or sand, so it is important to protect it as well.
These Presta valves are longer and narrower than the Schrader type valve.
Presta valves are only found on bicycles.
They originated on road bikes, where a narrower valve (6mm versus 8mm for the Schrader) meant a smaller valve hole (usually the weakest part of the rim).
These days you can find them on both mountain bikes and road bikes.
Instead of using a spring, the valve is held in place by a nut that holds it closed, although the valve itself seals "automatically" when the pressure inside the tire forces it to close.
With a schrader valve you can simply press the pin to release the air, but with a Presta valve you first need to unscrew the small lock nut. Don't worry about the nut coming off the end of the valve body because the threads are rounded to prevent this from happening.
There seems to be a myth that Presta valves handle high pressures better - this is probably not true given that there are Schrader valves that can handle many hundreds of psi (much more than you'll ever need). in your tire).
However, Presta valves are definitely a bit more fragile than Schrader valves. It is very easy to strike the threaded inner body of the valve, bend it or break it, so care must be taken. However, valve cores are easily replaced with standard tools.
Compared to Schrader valves, this requires a special tool.
Presta valves can be supplied with a retaining ring that secures the valve body to the rim. This can make them easier to inflate. The dust cap is not essential to sealing it, but helps keep the valve clean.
The only other type of valve you may encounter is the Dunlop (also known as Woods) valve. The base diameter is the same as the Schrader valve but can be inflated with the same pump as the Presta valve.
They are very popular on city streets in Europe and elsewhere in the world, but you are unlikely to find one in the UK or the US.
The tubeless valve is difficult to distinguish from a regular Presta valve.
Valves for tubeless tires are attached directly to the rim, not part of the inner tube.
Most often they are of the Presta type, but there is also a Schrader.
If you have a Schrader type valve like the one shown above, the first thing you need to do is remove the dust cap (if there is one).
Simply unscrew the cap counterclockwise to open the valve.
Now attach the pump head.
Inflate the tire to between the minimum and maximum indicated on the tire sidewall and remove the pump. Ready!
If your bike has a Presta type valve like this one, you will first need to remove the plastic valve cover (if any).
The plastic cover will open another threaded valve cover.
Loosen the threads, but be careful not to damage them in the process.
Now attach the pump head of your choice to the open valve and inflate the tire to between the minimum and maximum pressure indicated on the sidewall of the tire.
Inflate the tire to the desired pressure and remove the pump.
Finally, close the valve by turning it clockwise and install the plastic valve cover.
If you have a tubeless tire or a tube with sealant inside, there are a few extra steps you should take to avoid contaminating your pump.
Turn the wheels so that the valves are at the bottom and leave for a few minutes to allow the sealant to drain.
Turn the wheels so that the valves are up and inflate the tires. The same thing happens when the tires are deflated to prevent the sealant from splattering all over the place.
We would say that if you can only own one type of pump, get a foot pump for home use because it is efficient, fast and easy to use.
However, there is no doubt that having an extra mini-pump for the duration of the trip is very useful - otherwise you risk getting stuck on the side of the road in case of a puncture.
There is no limit to pump selection. Basically, they all do the same job, some of them look better than others.
From budget to outrageously expensive, you'll find something to suit your needs.
Mini pumps work but are much more difficult to use.
Again, there are many options that will fit in your pocket. We prefer hose mini pumps because it reduces stress (and potential damage) on the valve.
Another option for your inflation needs is the CO2 pump. They use compressed carbon dioxide in a small cartridge to inflate or fill a tire very quickly. Not something you would like to use on a regular basis, but perfect for emergency repairs.
The first thing to do is attach the pump to the valve.
Remove the valve cap, and regardless of valve type, we find it useful to let some air out to make sure the valve doesn't stick and opens and closes cleanly. Screw on the chuck, or push it in and lock it.
If your tire is completely flat, it may be difficult to install the cartridge at first because the valve tends to move back into the rim. Simply hold the valve at the back while pressing down on the outside of the tire so you can lock the cartridge in correctly.
The locking ring on Presta valves (if equipped) can also help by preventing the valve from dropping, holding it in place for you.
The connection to the valve must be tight. It is normal for a small amount of air to escape when installing the pump, but this should not last long. If so, remove and reinstall cartridge. If the problem persists, it might be worth checking the rubber seal in the chuck to make sure it's not worn out and needs to be replaced.
Remember to be careful with the valves - they are fragile. This is especially true if you are using a mini pump without a hose.
Be sure to secure the pump by hand to avoid applying too much force to the valve, which could cause damage.
When you start pumping, make sure you use the full stroke of the pump. You will find that most of the stroke is compressing the air to the point where it will be forced into the tire.
If you don't use the pump all the way, the air won't be forced out of the bottom - you need to pressurize to move the air from the pump to the tire.
Instead, you'll just end up wasting your energy to no avail.
With a floor pump, don't just use your hands, use your body weight to push down and pumping becomes much easier.
Sometimes you may find that the pump does not hold pressure, especially when inflating a tire from a fully deflated position. This may especially apply to older pumps where the seals may be slightly worn.
We find that vigorous inflation first helps to create enough back pressure (i.e. tire side rebound) in the system to ensure that the valves actuate properly and seal the tire. Keep going until you get the right pressure.
When the cartridge is removed from the valve, a hiss of air loss can usually be heard. This usually happens on the pump side, not the valve side. The pressurized air from the hose and cartridge just comes out.
The pump pumps air into your tire. The principle of operation is simple; you increase the pressure inside the pump until it exceeds the pressure inside the tire.
This "overpressure" forces air into the tire, which also increases tire pressure.
The pump is simply a manually operated piston. As the pump moves down, a check valve (allowing air flow in one direction) seals the piston chamber, causing the air pressure to rise as the pump is compressed. This pressure increases until it exceeds the pressure inside the tire.
At this point, the second one-way valve will allow air to flow from the pressure pump chamber into the tire. You extend the pump again, the check valve opens to fill the chamber with air, and you repeat the process.
To prevent leakage of tire pressure, the second check valve at the base of the pump closes. If it wasn't there, the pump would just open up again.
Presta valves close automatically, but spring-loaded Schrader valves are usually held open by a pin in the valve mount (meaning you don't need any additional inflation force to overcome the pressure exerted by the spring).
The pump head is also known as the cartridge.
The cartridge is the part that attaches the pump to the valve and forms an airtight seal over the valve. There is one of two designs: threaded or push-on with a locking lever. Most pumps nowadays can also be adapted to Schrader or Presta valves.
They will either have two different mounting points or a cartridge that can be changed for both types.
For large pumps (and many mini pumps too) the cartridge is often on the hose, preventing your force from damaging the valve.
Pumps are often equipped with a tire pressure gauge.
Proper tire pressure is perhaps one of the most controversial topics, but there are a few guidelines you can use.
As a rule of thumb, your tire should be strong enough to prevent it from flexing all the way to the rim, yet malleable enough to provide some suspension - after all, the beauty of a pneumatic tire is that you don't have an incredibly hard ride.
Most tires have a minimum and maximum pressure marked on the side. It is advisable not to go below or exceed these limits, because manufacturers have indicated them for a reason. Of course, this means there is still plenty of room to play around with the pressure and what works for you.
For mountain bikes, the problem is relatively easier to solve, as the goal is usually to improve traction, cornering, and damping.
As a rule of thumb, riders try to run as low pressure as possible without making it so soft that the tire squirms under load in a corner or flexes enough to damage the rim.
Things get a little more complicated for road bikes because along with grip and comfort, rolling resistance (how efficiently the tire rolls) is an important factor.
On all but the smoothest surfaces, a stiff tire will have no advantage, and instead of the tire being able to lean and conform to the bumps, causing the bike to move forward, you will bounce.
On all but the flattest surfaces, lower tire pressure can provide greater comfort and efficiency.
Testing showed that 20 percent tire compression (the amount of tire compression when a load is applied, measured by the height from the ground to the rim) was the optimal balance.
Incidentally, some manufacturers recommend the same level of tire compression, although this figure is somewhat controversial.
This value is indeed a good starting point for experimenting with tire pressures.
You don't always have to remove the pump/gauge to check tire pressure.
We recommend that you check your tires before every ride. Usually, you just need to squeeze them with your hand to check the pressure.
No, this is not very accurate, but you will quickly feel the pressure in your tires and be able to determine whether they need to be inflated or not.
If you get serious about this, you can end up with a pressure gauge that can read your tire pressure very accurately.
This is especially useful on mountain bikes where a few psi can make a big difference in handling and grip, but applies equally to a road bike to find the exact pressure that works for you.
You might be interested:
Author: hkc5twrt Sport
The route that will determine who wins the pink jersey in 2023 has been revealed. Here's what you need to know. The 2023 Giro d'Italia will be as old school as ever, with big stages, big mountains… Read more
Author: hkc5twrt Repair
Everything you need to know about one of the easiest chain connections. Quick release links can be used to secure the chain, making life much easier for you when servicing, cleaning or returning… Read More
Author: hkc5twrt Adventure
Solo bike tour in Russia Moscow Magadan.
Survival alone with a tent on a bike. By bike across Russia. Last 16 episodes not included in the playlist. Magadan is an absolutely extraordinary city…. Read more
Author: hkc5twrt Fitness
Essential tips for preventing sudden, catastrophic power loss. Bonk is a funny name for a terrible feeling when suddenly there is nothing left in the tank, the legs turn into jelly, and to get to the finish line ... Read more
Articles
