Keeping your tires pumped to the right pressure can make the difference between a great ride and a long walk home with the bike by your side.
Properly inflated tires not only provide a comfortable and safe ride, but also wear out slower. We all know that underinflated tires can cause problems, the biggest of which are snakebite punctures (when the inner tube gets pinched between the edges of the tire and the rim).
For the reasons we’re about to discuss in a moment, many cyclists think that slightly overinflated tires are actually a good thing.
But is it really so? Can you overinflate your bike’s tires?
You can overinflate your bike’s tires, and it isn’t recommended to do so. High tire pressure can lead to poorer ride comfort, uneven and faster wear, and even tire blowout.
So what’s the best tire pressure for a comfy ride and long tire life? And where do you draw the boundary between keeping your tires topped up and causing them harm?
Read on for the answers to these questions and more.
Why You Shouldn’t Overfill Your Bike’s Tires
Just as it isn’t a good idea to ride on soft, squishy tires, you’re asking for trouble by inflating your bike’s tires to rock hard.
Although there are isolated benefits to it, such as a smoother and faster ride, they far outweigh the risks. The biggest risk of them all is a tire blowout, which can cause you to lose control of your bike and fall off it, sometimes at high speeds.
Contrary to what some cyclists think, it doesn’t matter what type of pump you use. Whether you use a ball pump, a bicycle pump, a car pump, or you top up your tires at the gas station, always check the pressure on your tires.
Professional cyclists who know their bikes and tires inside and out can easily check this with their hands. Commuters and recreational riders, of which I am one, should use a tire pressure gage (or better yet, a pump fitted with one).
It’s True That Fuller Tires Make You Go Faster
In high school physics, they taught us that energy can neither be created or destroyed—only converted from one form to another.
When cycling, you convert muscle energy into kinetic energy. That’s a clever way of saying you move your legs to turn the pedals so the drive system can turn the wheels and get you and the bike moving.
You know you’re doing this right when the tires are the only thing that comes into contact with the road. And their pressure determines how much energy gets lost from the deformation of the rubber as the wheels turn.
The higher the pressure, the less the deformation.
When the tires are more inflated, the tire doesn’t deform as much. Less of your energy is lost in conversion and gets transferred to motion, which is why, by definition, higher tire pressure results in a smoother and faster ride.
But you can have too much of a good thing.
But Overfilling Your Tires Can Also Lead to Blowouts
A blown tire is the worst thing that can happen to a cyclist, whether in the mountains or on the road. I mean, who wants their tire to suddenly explode while they’re riding, especially at high speed?
It’s happened to me once or twice, and I wish it in no-one.
You’re riding along, and suddenly you hear a loud “pop” and a “pssst” as the bike starts pulling you in one direction and you lose 90% control. (If this happens, don’t brake, but steer the bike and pull off to safety.)
Of course, a blowout is never expected, and it will damage your tire and inner tube, but it can also lead to a bad accident. For safety reasons, it’s not worth the supposed benefit of overinflation considering that’s one of the risks.
And Make Your Ride (Very) Uncomfortable
If stiffness were the property of good tires, we would ride with metal, wood, or plastic tires instead of rubber. (Anyone who’s ever tried to ride an electric scooter on a cobblestone road will gladly explain to you why.)
High tire pressure increases the transmission of bounces and vibrations from the ground to you, the rider—for this reason, a very full tire on a very rough terrain can result in a very uncomfortable ride.
In fact, there are certain tire pressures you should use depending on the type of bike you have and the surface you ride it on. Sure, you can’t always take this into account, but it’s best to plan ahead whenever possible to ensure maximum comfort and safety.
Besides, It Causes Your Tires to Wear Out
When the tires on your bike are overinflated, the center will bulge out more than necessary. This leads to uneven contact with the road (and everyone else on it), which then places uneven pressure on the tires.
As a result, your bike’s tires will wear out faster and unevenly. So, by overinflating your tires, you will not only risk blowouts but get less bang for your buck and have to replace your tires after less miles/years.
All in all, not a good deal, even for the casual rider.
How Full Should a Bike Tire Be?
Bike tires typically have a pressure recommendation on the side of the tire, either in a range or a single number. In the case of a single number, this number is the maximum pressure for the tire.
As a golden rule, the ideal pressure for mountain bike tires is 30 to 50 PSI. Road bikes with 700c tires require a higher pressure, which is usually between 90 and 120 PSI. For exact numbers, refer to the manufacturer’s recommendation.
Finding the perfect pressure may take a little bit of trial and error, though. Tire pressure can also depend on things like your weight, the temperature, and the terrain you’re going to ride on.
If you don’t weigh very much, you can stick to a lower pressure for your tires because you aren’t exerting as much force on them. You’ll also want to use lower tire pressure when you need a larger contact area, such as riding on gravel or wet surfaces.
Remember that tire pressure will increase with temperature! So if you’re going out on a hot day and fill your tires to the maximum, there’s a chance the pressure will become too high when your bike is exposed to the hot sun!
How Do You Know When Your Bike’s Tire Is Full?
As I said earlier, it takes a while to learn the ropes for this. Luckily, there are guidelines to follow.
First of all, consider the pressure range on your tires. It’s a good idea to stick to somewhere within this range, and if you’re keeping track of your tire pressure, making small adjustments within this range should work for you.
If you want to check your tire pressure at a glance, you can do a visual or tactile check. For example, on a road bike, you should not be able to squeeze the sides of the tires easily when properly inflated.
On a mountain bike, the tires will be at a lower pressure due to the rougher nature of the ride. In that case, try sitting on the bike and monitoring the protrusion of the tire beneath. If it extends more than a few millimeters, you likely need to add some more air.