If you’re looking for a smooth ride, having the right tire pressure is key. Since air will slowly leak out of your bike’s tires over time, it’s a good idea to periodically check your tires to make sure that they’re pumped up properly.
You should check your bike’s tires with your thumb before every long ride. Bike tires can lose air after as few as four or five days, and you won’t always notice a small leak when it happens.
It only takes a few seconds to squeeze each tire before you depart on your ride. In addition to thumb checks, serious cyclists usually check their pressure with a gauge at least once a week.
Why Tire Pressure is Important for Cyclists
According to cycling experts, having properly inflated tires is important for smooth, easy rides. Failing to maintain a proper level of air will increase friction, reduce comfort, and can lead to more flats and tire replacements.
On most wheeled vehicles, inflatable tires serve a specific purpose. Unlike hard wheels, the flexible surface of a tire can conform to an uneven road or trail.
Internal air pressure is responsible for pushing the tire against the surface and supporting the rim inside of the tire. Imagine pushing an inflated balloon against a gravel road.
If the balloon is overinflated, it won’t make a lot of contact with the gravel and will pop if you push too hard. If it’s underinflated, it’ll flatten out like a pancake and allow your hand to get very close to the gravel.
Somewhere in between, however, the balloon will conform to the gravel surface underneath while maintaining its shape under pressure.
The pressure in your bike’s tires changes how much contact your tires make with the road surface. If you’re on a bumpy or wet surface, less air pressure will increase your traction and help make your ride smoother.
If you’re on a smooth, flat surface, however, you’ll probably prefer the reduced friction from having more air in your tires. Because of this, many cyclists adjust their tire pressure frequently for different types of riding.
How Does Tire Pressure Change Over Time?
Your bike’s tires aren’t completely airtight. Even a brand new inner tube or tubeless tire will slowly leak air over time. The higher the pressure in your tires, the faster this leakage will happen.
This is an especially big concern among road cyclists, as road tires are often inflated to pressures of 70 – 130 psi. The exact makeup of the air inside of your tires can have an impact on how quickly the pressure seeps out.
Carbon dioxide canisters have become a popular way to quickly top off a tire mid-ride for some cyclists. Unfortunately, this doesn’t provide a long-term fix.
Carbon dioxide is remarkably effective at passing through normal tire and inner tube materials, meaning most riders will have to top off their tires again when they return from their journey.
The air pressure in your bike’s tires can also go up over time.
This happens as a result of changes in air temperature. Charles’ law dictates that a rise in a gas’s temperature without a corresponding increase in volume causes a rise in pressure.
In most cases, this isn’t a big deal, but extreme temperature swings with highly inflated tires can lead to your tires popping. If you inflate your tires on a cold night, use a gauge to check the pressure if it’s hot the next day.
You might find that you need to let some air out in order to keep your tires from bursting.
Similarly, decreases in temperature will also lead to decreases in air pressure in your tires. Again, check your tires with a gauge if you think that the current air temperature has dropped significantly since you put air in your tires.
Checking Tire Pressure Is Important
As a result of these factors, the pressure in your bike’s tires isn’t constant over time.
Luckily, it’s not difficult to check your air pressure. When you pump up your tires, apply a bit of pressure with your thumb and pay attention to how much the tire resists.
From then on, you can check your tires with your thumb and compare the current feeling to how they felt right after you pumped them up.
You won’t be perfectly accurate, but you’ll get a great idea of how quickly air is leaking out of your tire. If you feel like something is off or you’re not sure, check with a gauge.
Having correctly inflated tires isn’t just important for ride quality and comfort. Proper traction ensures that you can maneuver safely and come to a controlled stop when you want to, preventing accidents.
Under-inflated and over-inflated tires can burst or go flat, meaning you’ll spend more money on replacement tubes or patch kits. It’s definitely worth the time it takes to check your tires periodically, especially right before you go for a long or demanding ride.
How Do I Know If My Bike Tire Needs Air?
If your tire visibly deforms when you get on your bike, that’s not a good sign. Aside from simply looking at your tire, here are four warning signs to look out for while you’re riding that will tell you your tires probably need air.
1) Your Bike Doesn’t Feel Steady While You Turn
It’s not always easy to tell that your tires are flat when you’re going straight. When you turn, however, the increased lateral shear on your tires makes it much more obvious.
If your tires are under-inflated, this pressure can cause them to fold and twist in awkward ways, causing your bike to wobble and lose grip. Don’t just take this in stride — get off and check your tires!
2) Your Bicycle Doesn’t Accelerate The Way It Should
Tires are flexible and elastic. If your rear tire is underinflated, this elasticity will work against your pedaling action. There won’t be enough pressure in between your rim (the part your pedals turn) and the edge of the tire.
The part of your tire that meets the road will try to stay put, causing an increase in elastic tension until something gives way. This means that pedaling your bike will feel like dragging a heavy weight with a big rubber band.
It’ll move, but there’ll be a lot of lag before anything happens.
3) Your Bike Feels Like It Drags
A properly tuned bicycle can coast for ages. Underinflated tires will dramatically increase the amount of friction between your wheels and the road, however, causing your bike to slow down to a halt much faster than it should.
If it feels like you’re wasting a lot of power pedaling and that your bike is slowing down rapidly, even when going downhill, check your tires first. It won’t always be the solution to your problem, but it’s the easiest thing to fix.
4) You Can Feel The Rim Hitting The Road
Bicycles need their tires to act as barriers between their wheels and the ground. Just like car wheels, bicycle wheels aren’t designed to support the weight of the bike and its rider on their rims.
Tires are designed to distribute weight evenly across the whole wheel. Riding on your rims will put all of the pressure on just one spot. Because of this, riding on your rims for even a short distance can cause serious damage.
If you feel your rims hitting the road or trail, stop riding as soon as you can and check your tires.
How To Check Your Tire Pressure
Most home bike pumps come with a pressure gauge attached. To check your tires, simply unscrew the cap, attach the pump to the stem, and lock it in place.
The gauge on your pump should move, giving you an idea of how much air is in your tire. If the tire is very flat, you may need to pump it up a bit before the gauge registers any pressure.
There are two additional things you should think about when checking your pressure with a gauge like this. First, make sure that you figure out what the recommended PSI of your tires is.
This is usually written on the side walls somewhere. If you’re riding on rough or wet trails or you’re on the lighter side, weight-wise, think about subtracting a little bit from this recommendation.
For smooth, hard trails and heavier riders, go over by a little bit. Second, many pump/gauge combos don’t actually measure pressure in the tire. Instead, the gauge indicates the pressure in the pump.
This means that your pump’s gauge might be off by 10 psi or more. If you can, calibrate your pump/gauge combo by comparing the results with a standalone gauge at least once.
The difference in measured pressure is fairly constant, so if you find out that your pump’s gauge is under by 5 PSI, you can use that number to generate accurate readings in the future.
How Often Should You Check Tire Pressure?
Bicycle tires can lose a shocking amount of air overnight, especially if the temperature changes rapidly. If you store your bike outside, check the tires with your thumb before each serious ride.
On average one should pump his bike tires at least once per week. But if you ride too often, daily or for longer distance then you should pump your tire at least twice a week.
Bikes that are stored indoors tend to maintain air pressure a bit better, but you still should check your tires before you ride if it’s been more than three or four days since your last check.
Your thumb isn’t perfectly accurate, so be sure to use a gauge if there’s any doubt about your bike’s tires. If you haven’t ridden for two weeks or more, you’ll probably want to start things off by hooking up a pump immediately.
If you’re going on a long or technical ride, consider using a gauge and getting the pressure in your tires perfect before you leave. You’ll make the experience safer, more pleasant, and more fun.
When To Check And What To Look For?
The best time to check your bike’s tires is right before you ride. Because bike tires lose air over time and pressure varies with temperature, checking your tires the night before won’t do you much good.
Instead, check your tires just before you leave to ensure that you get an accurate measurement.
When reading your tire’s pressure, consider three factors. First, look at the manufacturer’s recommended pressure for your tire. This can usually be found written on the side wall of your tire.
Second, consider the weight of the rider. Lighter riders can get away with slightly less air pressure, while heavier riders can benefit from slightly overinflated tires.
Finally, think about the characteristics of your actual ride. Bumpy, loose, and wet terrain all benefit from the increased traction of a tire that’s slightly underinflated.
On a smooth, dry, hard surface, however, this increased traction will only lead to more friction. To preserve energy and help your bike go faster, keep your tires inflated all the way when riding on well-maintained roads.
It’s Normal For Bike Tires To Lose Pressure Over Time!
Bicycle tires aren’t entirely airtight. Even the best inner tubes and tubeless tires will slowly leak air over time. The more pressure is in your tires, the faster this leakage will occur.
This means that your bike’s tires will slowly deflate, even if your bike is just sitting in your garage or living room. As a result, it’s totally normal to have to put a bit of air in your bike tires every few weeks, even if you don’t ride it.
Drastic temperature changes can contribute to this leakage. If your bike is stored outside, be sure to check its tires a bit more often in order to counteract the effects of changing air temperature on your tires.
Usually, a bike stored outdoors will simply lose tire pressure faster, but in some cases, you might actually find that your tires have become overinflated due to a rise in temperature after you pumped up your tires.
If this happens, simply let a bit of air out before you ride.
While you probably don’t need to use a gauge every time you ride, it’s a good idea to get in the habit of checking your tires with your thumb before you bicycle.
Underinflated tires can go flat, slow down your bike, and can make your bicycle harder to control, leading to accidents. Overinflated tires are prone to bursting, especially on hot asphalt on a hot summer day.
Take the time to learn what proper pressure feels like, check your tires, and investigate any doubts that your thumb uncovers with a gauge. You’ll keep your rides safe, smooth, and fun.