August 26, 2022 4 min read
A parents’ guide to why tire pressure matters and how road vs trail riding is different.
Tire pressure is important to a kid's riding experience. A properly inflated tire will make the bike perform better, and help reduce the risk of flat tires.
PSI. PSI or “pounds per square inch” is simply the measure of pressure resulting from a force of one pound-force applied to an area of one square inch. This gives us a number which we can use as reference for how much or little air is in the tire. Most quality bicycle pumps have gauges which read in PSI but pump gauges are often inaccurate. A dedicated pressure gauge will give you a more accurate reading.
All pneumatic tires, like car tires and bicycle tires, are pressurized by an “air-tight” chamber. In bicycles, this sealed air chamber is either a tube or a sealed tubeless tire. The higher the PSI, the harder the tire. The lower the PSI, the softer the tire.
With experience you can often check tire pressure by squeezing the tire with your thumb. For neighborhood riding, a good rule is that the tire should feel about as firm as a soccer ball. For casual neighborhood riding, a thumb pressure check is often enough to make sure the tire pressure is within a safe operating range. During certain types of riding, like trail riding, small differences in tire pressure can make a big difference. So, many performance oriented riders use pressure gauges almost every ride.
Tires require a certain amount of air pressure to prevent them from bottoming out on the rim. Because wider mountain bike tires have more air volume, it is possible to ride them at lower pressures, increasing both comfort and traction on the trail. By comparison, narrower road tires have much less volume so they need more PSI to prevent bottoming out and pinch flats.
All bicycle tires have a manufacturer's suggested range of pressure that can be found on the sidewall of the tire.
So now that you have a range, here's a rough guide to help you figure out where to operate within that range:
|Type of Riding||Tire Pressure|
Many parents of trail riders will run tubeless tires below the minimum recommended tire pressure. Running the pressure too low increases the risk that the tire could bottom out against the rim, that the bead could separate from the rim causing the tire to lose pressure (with tubeless setups), or that there could be a pinch flat (with a tubed setup). Nonetheless, many parents think these risks are worth the gains in traction and comfort, especially for trail riding. As a bicycle manufacturer, our official position is that you should operate within the tire manufacturer's recommended pressure range. But to be clear, our lawyers made us say that.
Another factor to consider is rider weight. Lighter weight rider's can typically benefit from lower tire pressures.
The general rule is that:
Experiment to find the right balance for your rider. Finding the “sweet spot” for your kiddo’s weight and the terrain they are riding (paved vs trails) will help improve their riding experience.
For riding around the neighborhood, you don’t want to run too low pressure as this will increase the chance of a flat tire, bottoming out of the rim, having the tire rolling off the rim and create slower rolling speeds. It's common for kids' bikes with tubes to get pinch flats if the tire pressure is too low. A pinch flat occurs when the tube gets pinched against the rim when kiddo rides over a curb which will cut the tube and possibly damage the rim of the wheel.
For Mountain biking and trail riding, the desired pressure is lower to increase traction and comfort for the kids on rougher terrain. Introducing “tubeless” tires (removing the inner tube) is great for this as it decreases the chance of a flat tire and allows you to run even lower pressures for the kids. But note that running a bicycle tubeless requires more than simply removing the tubes - it requires a specific type of tire and rim combination and the addition of tubeless valves and sealant (more on this is in another post).
Bicycle tires leak air much faster than car tires. Because of this, it's a good idea to do a quick tire pressure check before every ride. Even if you are not a performance oriented rider, at a very minimum it's likely that you'll need to add air to the tires every 2 to 3 weeks.