The 7 Factors that Affect Your Bike Tire Pressure

Jan Poshenko
Written by
Last update:

Cyclist's Weight

Your weight on the bike is definitely one of the factors that will affect your bicycle tire pressure. The heavier you are, the higher the pressure inside the tires. If you’re a normal weight cyclist, then your tire pressure can vary from 100 psi to 120 psi. However, if you are overweight, then the tire pressure can be as high as 180 psi.

You can increase the pressure inside the tire by using a heavier wire. There are commercially available heavy-duty wires that you can use to increase the pressure of your tire by about 50%. For example, if you are a cyclist who weighs 80kg, then the pressure inside your tire can be increased from 120 psi to about 150 psi.

Tire Width

When it comes to tire width, fatter tires can be used at lower pressures than skinny tires. As you increase the width, the tire has more volume. You can increase the volume of the tire without adding a lot of pressure.​ So you can have your bike set up in a way where it’s comfortable to ride.

Tire Pressure Set at 25psi, a 2.25-inch wide tire can hold considerably more air than a 1.5-inch wide tire, which we noted in the table below. And, that’s what we’re ultimately looking for, right – more air in the tire.

Tire Pressure A 23C 1.8-inch wide tire at 100 psi can carry more air than a 25C 1.95-inch wide tire at 100 psi can. But the 100-psi 25C will carry more air than the 100-psi 23C.

Air Pressure

Of course, the table below is a general reference based on a straight-pull valve.

Tire Width

(inches)

Width

(millimeters)

Weight

(pounds)

Inflated

(psi)

Tire Type – Tubular vs. Clincher

A tubular tire incorporates a thin, lightweight tube inside the casing. The best tire technology today uses latex (rubber) in the inner tube, which is about half the weight of butyl. In fact, many people say that there is no difference in puncture-resistance between butyl and latex tubes.

A tubular tire is considered a high-end tire. They are available in road and mountain bike designs.

The tire is glued to the rims. Tubular tires are sometimes used in the high-level track bicycle. Tubulars have a very thin are glued to a lightweight rim. Most people do not use tubular tires in public because they need to be mounted professionally and can be very expensive.

Clincher tires have a casing and a separate inner tube. The casing and tube are connected by a bead, which is made of metal, plastic, or kevlar.

This is the most conventional tire, and the most commonly used. It is also the cheapest of the three types of tires. This tire combination is considered the standard wheel/tire package. A clincher tire is much lighter than a tubular.

Tire Compound

The tire compound is the most important element when it comes to finding your desired tire pressure. The compound is the rubber mixture that makes up the actual tire. The 7 most common compounds are:

  • Black Chili”
  • Red Chili”
  • Orange Chili”
  • Ruby Red”
  • Blue”
  • Yellow”
  • Green”

The "chili" compounds have a softer feel and softer rebound rate than the traditional spongy smooth rubber tires. They are also stickier and respond quickly to braking.

Generally, softer compounds come at the expense of durability. The "Blue" and the "Yellow" compounds are the most popular. The Blue compounds are usually used for racing because they come with low rolling resistance and great traction. The "Yellow" compounds are usually used for training because they come with high rolling resistance and traction but they can last longer.

Internal Rim Width

While your tire is the most important part of the equation (with the rim coming in second), the third most important element is the width of your internal rim. All rims are measured across their internal width, eg: 23mm.

Many tires are designed to work at their best with a certain rim width. For example, a 700x23C tire is designed to work at its best on a rim that’s 23mm wide.

If you try to fit it on a 21mm wide internal rim, it may seem to be a tight squeeze, but will roll just fine. However, you’ll experience loss of tire pressure power and an increase in rolling resistance on a wider rim.

For a tire to reach its optimal performance potential, the width of the tire should match the width of your internal rim.

This is especially true when the tire width exceeds 25C, because each cm of added width requires significantly more inflation pressure to maintain performance.

Tire and Tire Lug Nuts

Lug nuts are the second biggest factor that affects the pressure in your tire. These are a cocktail of steel, aluminum, magnesium, plastic, and rubber.

Generally, you’ll find that almost all bikes today use aluminum, and cheaper tires often have plastic.

Riding Terrain and Road Surface

The riding terrain and road surface are the first things to consider. Your riding surface and riding surface will affect your air pressure. Pavement, dirt, sand, gravel, all will have an impact on your air pressure. So whether you’re riding on the road or off-road, it’s important to know the specifics of your riding surface.

Mountain biking is generally done on rough terrain with a lot of bumps. This means you have to be more careful with your tire pressures. You want higher air pressure in your tires, so they can handle the sharp rocks and grass that you’ll encounter. These conditions will force you to use tires with a higher air pressure, as you wouldn’t be able to handle the rocks and small bumps with a lower pressure.

Road biking is generally done on smooth surfaces, over large bumps and inclines. This means you’ll need to have lower tire pressures. Higher pressures, like in mountain biking, can cause the tires to pop and lose pressure. Lower pressures are more appropriate for your riding terrain.

Riding Conditions

  • Pavement: The most commonly ridden surface: smooth and flat. As you ride and the road or your tires heat up, more air escapes the tire. The more air you lose, the stiffer the ride. Try dialing in between 12–13 psi.
  • Gravel: Asphalt roads may have some gravel on them, but the dirt is what makes a true gravel road rougher and bumpier. More air means more cushioning and smoother riding.
  • Off-Road: Run between 15–17 psi for hard trail riding.
  • Mud: A sticky mess that will completely soak your tires. Less air means less weight and wet tires are lighter and more easily move through the gooey muck. Try running 6–8 psi when crossing streams and pushing into the mud.