All bike tires slowly leak air every day. Even if you’re an occasional rider, and you only take your bike down from the bike rack once a week, the tire pressure will still decrease. Before you ride, you should always check your tires’ PSI and, if needed, inflate them with a floor bike pump or a handheld pump.
On the sidewalls of your tires, you’ll see the manufacturer’s recommended pressure range for PSI (pounds per square inch). Different bike tires have different ranges, and narrow tires need more pressure than wide tires. The recommended PSI for different tires are:
Experienced cyclists can often estimate whether their tires need to be pumped by pinching the tire between their thumb and forefinger. The more accurate way of knowing when your tire should be pumped is by measuring its pressure with a pressure gauge; if the air pressure is measured below the recommended PSI, it’s time to pump.
First pump your bike tire to the middle of the range for the recommended PSI. You also need to take your body weight into account. Tires that bear a heavier rider need more PSI. Weather conditions and terrain also affect how a bike rides, so you’ll need to experiment with different PSIs to feel what’s most comfortable to you.
A Schrader valve is the type of valve you’ll find on car tires, older bike tires and mountain bikes. It consists of a metal pin in the center of a threaded valve, and a rubber cap that’s screwed onto the valve. Most bike pumps like those we reviewed have a dual head to accommodate both Schrader and Presta valves or a single head with an adapter.
A Presta valve is found on road bikes and some mountain bikes. It’s a slender valve with a nut at the top that is loosened and tightened before and after inflation. Almost all new bike pumps have a head with openings for both Schrader and Presta valves, or they have an adapter for switching from Schrader to Presta, like one of our top picks, the Topeak – Road Morph G.
If you’re out riding and your tires need air, you could give them a quick inflate with a CO2 injector, like the one we reviewed. But if you don’t have a CO2 injector in your bag, and you forgot your mini pump, then you can pull into a gas station and inflate your tires there.
If you don’t have a pressure gauge, ask the station attendant for one. Inflate your tires to optimal pressure in short bursts; a gas-station air pump has very high pressure, and you run the risk of popping your tire.
A gas-station air pump will only fit a Schrader valve. But if your tires have Presta valves and you don’t have a Presta valve adapter, there’s still a way to inflate them.
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Gene Gerrard, Writer
Gene has written about a wide variety of topics for too many years to count. He's been a professional chef, cooking-appliance demonstrator, playwright, director, editor of accountancy and bank-rating books, Houdini expert and dog lover (still is). When he's not writing for Your Best Digs, he's performing as a magician at the Magic Castle in Hollywood.
I headed off from my house one Saturday early in my biking career, drooling with excitement for the mountain bike ride I’d been awaiting all week. Then, before I had reached the trailhead, I noticed my rear tire was significantly low. I felt like I was riding through mud – on the pavement! Remembering a gas station with an air pump on my way to the trailhead, I figured I could easily pump up my tire without a wasted trip back to my house.
But, when I tried to inflate my mountain bike tire… AAACK! Foiled! The gas station had a standard car pump and, new biker that I was, I forgot my bike tires have a presta valve. A week of hungering for a mountain bike ride… RUINED! All because of a puny little valve. Oh, the angst. Do NOT let this happen to YOU!
Unless you grew up biking, most of us are so familiar with car tire valves, we assume it’s the only type of valve. In truth, car tires use what’s called a Schrader valve. It’s about the diameter of a pencil and has a tiny “button” in the center that, when pressed, allows air in or out, but holds air pressure relatively steady when not compressed.
Presta valves, on the other hand, are significantly skinnier than Schrader valves. They don’t have a button in the center of the valve and instead have an attached screw mechanism at the tip. When screwed closed, it holds air pressure in the tire. When unscrewed, you can pump air in or release air out.
Presta ValveCurrently, presta valves are the most common type of valve on high-end mountain bikes. Racers and high performance cyclists prefer them. They’re becoming increasingly common – even on mountain bikes on the low-end of the price spectrum.
Why, you ask. (Perhaps with a significant number of swear words as you kick your flat mountain bike tire or throw your useless Schrader pump.) Why use an uncommon, obscure valve that doesn’t fit a standard pump? Is it just to make mountain bike newbies suffer? Why? Why?
No, it’s not just to frustrate you.
Presta valves are generally more reliable and allow pumping your tires to a more precise pressure. By virtue of design, all Schrader valves release tiny amounts of air over time, requiring occasional “topping off”. Having a cap on the valve can significantly decrease the air loss, but it still means, at any given moment, your tire may not have the pressure you pumped it to.
A casual mountain bike rider may not know what pressure they should be riding or even notice when the pressure is off. But for high-speed riders, tire pressure can have a significant impact on speed, race performance and riding safety.
The screw on the tip of the presta valve allows a rider to close off the tube at the desired pressure and not require a cap. Barring an unnoticed leak or a puncture during a ride, the tire will now reliably hold the pressure you want.
You can inflate a presta valve with a common air pump, such as at a gas station or portable air compressor. However, you need an adaptor that’s ridiculously small in size but huge in importance: a presta valve adaptor.
Presta valve adaptorHere are the steps to inflate a presta valve with a standard pump:
Since more and more mountain bike tires use presta valves, most bike pumps are either universal (meaning one hole works on both presta and Schrader valves) or they have two separate holes, one for each valve type. However, you should always carry a valve adaptor when you ride for situations when a standard pump is the only option. Some cyclists do this by keeping a valve adaptor screwed on their tire valve all the time. Just make sure the valve is screwed closed before putting the adapter on!
Presta valve adapters are extremely tiny and portable. This also means they’re easy to lose. The good news is they’re fairly cheap. I usually buy a handful at a time and keep one in my garage bike tools and one in my portable tool kit for rides. Having one in your glove box isn’t a bad idea, either!
All bike shops sell valve adapters and some general sporting goods shops and hardware stores carry them as well. You can also buy valve adapters online easily and cheaply.
This simple question actually does not have a straightforward answer. The simple rule is to refer to the tire manufacturer’s specs on tire pressure that are printed on the sidewall of your tires. Consensus of riders is that mountain bike pressure should be 30 psi on the front tire and 33 psi for the rear tire. This information should serve you well if you have only a casual interest in mountain biking and are doing entry-level to intermediate trails two or three times a month.
However, if you spend a significant amount of time on your bike (and an equally significant amount of time dealing with pinch flats, blowouts or skidding out on corners), you’ll want to dive deeper into the science of bike tire pressure. DIY Mountain Bike has a fabulous, in-depth article and survey results examining appropriate bike tire pressure.
The fastest and easiest (and cheapest) way to check your tire is with your hand. When you squeeze it, it should be hard in the center with only a tiny bit of give farther out on the tire near the treads. A hand test, however, is – not surprisingly – not very accurate!
If you want to be precise, a tire pressure gauge will be necessary. But be warned: tire pressure gauges are notoriously unreliable and the sensitive sensors are easily broken. For my recommendation, read my tire pressure gauge product review.
If you’re in a pinch (perhaps literally!), and you don’t have a universal pump or a valve adapter, you can modify a tube cap to create a functional adapter using a presta valve CAP.
Remember to screw the tire valve shut after inflating! I know you’re tired of hearing that, but it’s important.
Now that you know everything you need to about how to inflate a presta mountain bike tire, you’ll never find yourself hungering for a ride and find yourself deterred by a standard tire pump!
And don’t forget to screw the presta valve closed…
Professional writer Kat Jahnigen was 2 miles from the nearest village – and roughly 2,310 miles – from the nearest English-speaking town – when her bike tire burst. At that time, she was a college student on a bike trip across the desolate, rocky island of Crete. It suddenly occurred to her that it would’ve been good to learn some basic bike repairs before setting off on a solo bike trip.
Check out Kat’s website WriteHire at writehire.net.
Tubeless tires can hardly be called the know-how of the bicycle industry, however, they still raise questions for many. The topic itself, as a rule, is surrounded by a lot of skepticism and distrust, which are more often explained by a lack of understanding of basic things and a lack of experience in riding such wheels. To dispel all these doubts, we answer the main questions related to tubeless technologies.
These are bicycle tires that do not have a tube. At the same time, tubeless technology is not only about tires. We are talking about a whole wheel system, which also includes a special rim and a sealant that gives the wheel anti-puncture properties. The tubeless concept makes the bike more comfortable to use and improves its riding performance, which will be discussed in order.
How long ago did this technology appear and can it be trusted?
Those who hear about bicycle tubeless for the first time usually tend to be suspicious of them. You can dislike this technology for subjective reasons, but you definitely shouldn’t distrust it. Tubeless tubes have been massively used for cars and motorcycles for several decades, and during this time they have not given reason to doubt their reliability.
The first tubeless systems for bicycles appeared in 1999, when the French rim brand MAVIC, in collaboration with tire manufacturer Hutchinson, presented their concept of a simple and effective tubeless wheel. In the 2000s, this technology remained the prerogative of mainly professional athletes, who quickly appreciated its main advantages: lighter weight, more air in the wheel, good "traction" and durability.
In recent years, tubeless has finally ceased to be perceived as something exotic. For example, today a significant part of the MTB and almost all touring cars come with such wheels as standard. A wide variety of sealants are also available on the market, and the number of those who are discovering the benefits of tubeless technology is steadily increasing.
The tubeless system provides a special rim and tires that are labeled tubeless ready or TR. However, the rims themselves are easy to distinguish visually - they have a low side and characteristic walls with recesses, forming a kind of lock in which the tire cord is wedged when air is injected. Due to this, in the inflated state, the rubber reliably and hermetically “sits” on the rim, without breaking off the wheel even at low pressure. The rim itself is additionally glued with a sealing tape, after which the nipples are installed separately.
The benefits of tubeless wheels are revealed no matter how often and what kind of bike you ride: whether it's weekend trips, extreme downhill or long-distance touring. Nevertheless, for certain categories of cyclists tubeless still open up more opportunities: first of all, we are talking about those who are seriously passionate about off-road.
When actively driving off-road with tubeless tubes, you can ride on lowered wheels and at the same time not be afraid of such an unpleasant type of puncture as a snake bite. Low tire pressure, in turn, gives better handling, dampens vibrations more effectively and generally provides more comfort on difficult tracks. If we are talking about cyclists, then they appreciate tubeless for their anti-puncture qualities.
Road bikes also use tubeless wheels. Moreover, they are the pioneers of this technology. But road tubeless tubes are a different story: they are designed for different operating pressures and have tangible design differences. Therefore, further we will talk mainly about those tires that are put on mountain, touring and city bikes.
These are the two rim formats that define the features of a tubeless wheel assembly. BST is a standard that involves the installation of a special sealing tape that prevents air from leaking through the holes in the spokes. This is the most common version of tubeless systems.
UST is a blind rim in which an additional bridge isolates the spoke holes. Thus, there is no need for laying a sealing tape. In practice, this greatly simplifies life, because when installing a tire (especially without proper experience), the tape tends to crush, which is why you have to reassemble the wheel. It is easy to guess that such rims also have a drawback - their price.
The tubeless system in the form in which we wrote it above is already a full-fledged wheel, it can be installed on a bicycle and hit the road. But there is an important nuance. First of all, tubeless tubes are valued for their anti-puncture qualities: for this, a small amount of a special liquid, a sealant, is poured inside the tire.
Yes, you can. But you should not do this. Firstly, this is illogical: for no reason you are depriving yourself of the main advantage of tubeless - the anti-puncture effect. But more importantly, it is very difficult (or even impossible) to inflate such a tire in a completely flat state with a portable pump: to do this, you need either a strong floor pump or a booster. Naturally, no one will take such bulky things with them on the road. Filled with sealant 95% of punctures "seal" without a critical loss of pressure, and in most cases there is no need for even light pumping. Thus, the probability of being with a flat tire is very low.
So, if you put tubeless, sealant is still needed. Such fluids are easy to find in any bike shop, they are inexpensive and require replacement on average once every three to four months, so there is no need to talk about any inconvenience. Yes, in order to cope with the fill, you need to acquire a certain skill, but this is much easier than constantly changing broken cameras. In addition, sealant can be replaced once a season in a specialized service.
Bicycle sealants are based on fine particles (rubber or polymer fibers) suspended in a liquid carrier. Inside the wheel, the sealant does not polymerize: it is in a liquid state and is distributed along the inside of the tire during movement. When a puncture occurs, the air flow begins to push the solution out. A fine suspension clogs the hole, and the sealant dries quickly. Thus, there is a reliable "sealing" of the puncture.
If we talk about typical punctures - collisions with thorns, wires, small glasses - such damage is self-healing without a noticeable loss of pressure. Usually, a puncture can only be guessed from a small spot on the surface of the tire. Naturally, the sealant works with more complex damage. You can count on it even if you pierce the wheel with a thick nail, 4-5 mm in diameter. If you don't understand how a liquid can seal such holes, you can watch numerous crash tests on YouTube that demonstrate the miraculous properties of sealants.
The consumption per tire is from 50 to 100 ml. If we are talking about standard MTV tires, the golden mean is about 60 ml per wheel. The exact dosage will always be written on the bottle. It is difficult to get confused even for those who do not like to read instructions: most sealants have measuring containers or a dosage scale on the bottle itself.
Here, too, everything is conditional and depends on the characteristics of the specific composition and intensity of punctures. In the absence of serious damage that entails the leakage of a large volume of sealant, you can easily skate a whole season on one fill. Some cyclists prefer to do an incomplete start-up gas station and gradually add 20-30 ml of fluid every two to three months. You can also navigate by how effectively the sealant works: if you see that small punctures are sealed with a strong deflation of the wheel, it may be that the composition is no longer enough and it needs to be added. Be that as it may, sealant is a very economical thing that lasts for a long time.
The sealant inside the tubeless tends to dry out, forming a characteristic film. Whether or not to clean the tire cavity is up to you. This is a purely aesthetic moment, which does not affect the operation of the anti-puncture fluid. The sealant can simply be added as it dries and not bother with unnecessary worries. It is more likely that the tire will completely wear out than it will have time to completely clog with dried filler.
Serious damage - large diameter punctures, small cuts, run over nails with subsequent tire rupture - are repaired using special repair worms. These are rubber or fibrous bands that are inserted into the hole to reduce its area and allow the sealant to seal the puncture.
With long longitudinal cuts it is more difficult. Here you need to either sew up the dissection with nylon threads, or stick a patch on the inside of the tire. You don’t have to worry about the tightness of the repair site - the sealant will do this work, of course, if it does not have time to leak out. But being able to inflate a completely flat tire with only a portable pump will require skill.
In fairness, we note that such complex injuries are rare for most cyclists. But for those who are seriously passionate about off-road, it is better to play it safe with a spare camera. In this case, having caught a cut, you can always drain the sealant, unscrew the nipple from the rim and install a regular camera. And in order not to drive with a “hernia” protruding outward, we recommend placing, for example, a bill folded in half under the cut on the tire.
Tubeless allows you to forget about such an unpleasant form of damage as a "snake bite" forever. It usually happens when at full speed you catch a pothole in the pavement, unsuccessfully jump onto a curb or run into a stone on a downhill. Hitting the edge of a hard object, the tire is crushed, and the rim walls work like incisors, damaging the chamber in two places. In tubeless wheels, this scenario is excluded, because. there is nothing to break through here. Of course, it can be assumed that the rim will cut the tire itself, but this should be a blow of enormous force, which is almost never encountered in practice.
Rejection of the chamber increases the volume of air in the wheel. This changes the contact patch (it becomes flatter) and allows the wheels to better absorb off-road bumps. Add here the ability to ride at low pressure, without being afraid of a snake bite, and it becomes completely clear why tubeless lovers of hard off-road riding so idolize. Soft tires with a large contact patch "fit" all the bumps in the road, giving excellent traction on rocks, forest primers and other off-road.
In addition to traction, tubeless tires improve shock absorption, dampen vibrations better, and generally provide more off-road comfort. At the same time, to get the most out of this rubber, you need to experiment a lot with tire pressure, trying to find the indicators that will best suit your individual riding style.
Finally, the camera is extra grams. By refusing them, you can save an average of 70-100 g of weight on each wheel. For some, this may seem like a formality, but it is worth considering the fact that extra grams on the periphery of the wheel have a stronger effect on driving performance. This difference is especially felt on road bikes: road bikes, gravel, touring.
They also exist. Moreover, it is far from formal. First, it's the price. The difference becomes especially noticeable when you buy tubeless systems separately: rims, tires + small things (tape, removable nipples, sealant). For tubeless you will have to pay an average of one and a half times more than for ordinary wheels, plus or minus the same class. And if we are talking about more advanced UST rims, then this means another + 30-40% to the cost.
With tubeless by default, everything is more difficult in terms of installation (here we are talking about conventional BST systems). You need to learn how to properly glue the tape, accurately insert the nipples, carefully install tight rubber, making sure not to displace the tape and not fill everything with sealant. On the other hand, all this comes with experience, but what you will always have to put up with is the difficulty with pumping a completely flat tire.
A tubeless tube cannot be inflated until its landing board snaps into place on the rim. To do this, you need to sharply introduce air into the tire. The tire should straighten up and fall into the grooves with a characteristic click - then it can be safely pumped further. This all sounds simple if there is a compressor in the garage. Putting a tubeless tube into the grooves by pumping air with an ordinary floor pump is quite difficult, and almost impossible with a portable bicycle pump.
All this makes life much more difficult. But there are solutions. In the field, a compact can of compressed air can help out. At home, installing tubeless tubes greatly simplifies the booster. This is a cylinder into which a high pressure is pumped with a pump, then it is connected to a nipple, the valve is lowered - and the air from the reservoir pumps up the wheel sharply.
As you can see, tubeless cameras also have enough disadvantages, but it is wrong to consider them in isolation from the advantages. For example, the probability of being with a completely flat tire away from home is very low, due to the anti-puncture qualities. Complicated installation is offset by the lack of punctures and roadside repairs. And by overpaying in price, you save on interchangeable cameras, and, of course, win as a roll on off-road.
June 9, 2017
A puncture of a wheel (more precisely, its chamber) always happens suddenly. If trouble has overtaken you near the house or any other housing, it is not so difficult to find tools and seal the puncture site. If there is a bike service or shop nearby, they will always tell you how to change the camera on the rear or front wheel of the bike, and for a fee, they will do everything themselves. But if the puncture occurred in nature, far from any benefits of civilization, you will have to rely only on your own strength and the available repair kit.
When traveling far from civilization, your own repair kit is the only thing that will help with a puncture. You need to select it carefully.
And then an unpleasant moment came - the bicycle wheel was punctured. You should start with a visual inspection of the tire. In some cases, if the hole is very large, it helps to immediately determine the puncture site. For convenience, this place can be immediately marked with a pen, marker, piece of charcoal, chalk, or in any other suitable way. Even if the intended location of the hole is found, it is still recommended to fully check the entire wheel, clearing it of debris. It may well be that there are several punctures.
After inspection, remove the wheel (using the appropriate wrench from the repair kit). Now you need to remove the tire from the rim and get the camera out of it. It will be difficult to do this without the side rails included in the repair kit described above. It is necessary to insert the beads between the tire and the rim and pull them, gradually removing the tire. Removing the inner tube is usually easy, but if the tire is too stiff, it may be necessary to re-use the beads in the same way, only now they will need to be inserted not between the rim and the tire, but between the tire and the inner tube. If at the previous step the alleged puncture site has already been found and marked, it is recommended to additionally mark the same area on the camera. More clearly, how to remove or change a tire with a camera on a bicycle, is shown in this video:
When the camera is removed, the puncture site must be found on it. If it is already checked, it will be easier to search, but you still need to check the camera completely. To do this, you need to pump it up and by ear determine where the air comes from. If the hole is large enough, then this is not difficult to do, but if it is very small, you will have to act differently. You will need a container of water. It is most convenient to use a basin, but it is difficult to find it in the field. In this case, any body of water is suitable: a river, a lake, a reservoir, etc. You need to place an inflated chamber in the water and check where the air bubbles come from. This is the puncture site. It is important to remember that for repairs, you must first allow the camera to dry. But that's not all. While the chamber dries, it is recommended to carefully check the inner surface of the tire. There may be glass particles, thorns, and other similar elements that made a hole in the chamber and can make a new one. They need to be removed.
Once the hole is found, there is no other option but to patch or change the bike tube. With the replacement, everything is simple: we take out the broken camera, change it to a new one and install it back. But with a patch, the situation is more complicated. First of all, it is necessary to carefully process the puncture site and everything around it with sandpaper. A rough surface will allow you to better fix the patch. Now dripping glue. One drop is enough, which should be rubbed with a thin layer around the hole in a radius of about 2 cm. Then the glue should be allowed to dry a little and repeat the same procedure several times until the glossy glue layer becomes matte. Only now you can glue the patch. If they are available in different sizes and it is not clear what the actual size of the puncture is, it is better to take a larger patch. After the glue has dried, it is recommended to pump up the chamber to check if there are any other holes and if the patch is not letting air through. If everything is fine, you can install the camera in the tire and put the latter on the wheel rim.
There are a few tricks to make repairing a bicycle tube puncture more comfortable.
Tire repair not possible.