These tires give a plush ride regardless of pressure. And because they don’t have stiff sidewalls to help prop up your weight, it’s inadvisable to run them with a low PSI. Supple tires flex more than vulcanized tires, even when their tire pressure is high. The sidewalls are flexible and there are usually two layers of casing rather than three.

With supple tires like tubulars or open tubulars, you are effectively riding on air. The way a tire is made has a bearing on tire comfort and affects how much PSI you need. In theory, at least, any puncture is automatically sealed and you can continue on your ride. Of course, the chief benefit of tubeless tires is that you can run low tire pressures and the risk of punctures is inherently mitigated. That lets you run a slightly lower PSI without running much risk of pinch flats, at least on a road bike. One way that larger tires allow lower pressure is by their greater air volume and physical size. Conversely, a tire that’s pumped up to a high PSI hits obstacles harder, causing discomfort as you ride. Tire pressure directly affects ride comfort because a softer tire absorbs vibration from the riding surface. There’s scope for disaster in certain situations.Įven in perfect riding conditions, a tire that is too soft and “squirmy” does not corner well and may risk the sidewall collapsing, potentially causing an accident. Braking heavily on rim brakes (e.g., on steep descents) also increases PSI. If you pump your tires to the max and go riding in extreme heat, they may end up overinflated. Lowering pressure a little increases tire traction on icy roads, for example. You can adjust PSI to suit various weather conditions. The PSI Safety Aspectįrom a safety standpoint, it’s always useful to know if the PSI in your tires is too low or too high. Why Is Bike Tire Pressure So Important?īike tire pressure affects three key aspects of cycling: safety, comfort and speed. Those are designed for car tires with much greater air volume.

A lower PSI does not automatically make one tire softer than another (think of car tires).Īir volume is a vital concern if you ever think about using an automatic air pump at a gas station on your bike. The wider a tire is, the more air volume it has, and the lower PSI it needs to achieve the same “hardness”. You may also see a maximum PSI on wheel rims, which contain the tire pressure.Īir pressure is directly related by Boyle’s Law to air volume. There will be a maximum PSI that you shouldn’t exceed if you want to avoid hazardous tire blowouts or tire deformation. PSI (pounds per square inch) is the unit you’ll normally see written on the side of bike tires. One bar is equal to 100 kPa (kilopascal). Since it uses pounds and inches, PSI is an imperial unit of measurement whereas the bar is a metric measurement. Air pressure gives the tire its shape and decides how much the tire flexes as you ride. These units of measurement gauge air pressure inside the tire. What Is Bike Tire Pressure And What Is PSI?īike tire pressure can be either measured in bars or PSI, but the latter is more common. Bike Tire Pressure Chart And Pressure Recommendations.Why Is Bike Tire Pressure So Important?.What Is Bike Tire Pressure And What Is PSI?.

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