Why is gravel bike tire pressure so important?
Finding the optimal tire pressure will make your gravel riding easier and more comfortable, and you'll find increased grip on all terrains and a reduced risk of punctures. Optimizing gravel tire pressure is also crucial to reducing rolling resistance and improving comfort.
If the tire pressure of your gravel bike is too low, it will take more effort to maintain the speed you want, and energy will be lost in tire deformation and friction between the tire and the ground. You also run the risk of sidewall and rim damage. When you ride, the tire will move relative to the rim. If you are using tubeless tires, lower tire pressure may create cavities in the tire and rim, which will accelerate deflation.
If the tire pressure is too high, the tires will transmit vibrations from the road to your hands, resulting in reduced comfort and wasted energy. Over-inflated tires absorb less vibration when you hit a rock or tree root, and are also less likely to skid. An over-inflated tire may also slow overall speed because it cannot deform to accommodate imperfections in the road.
Stiff doesn't always equal faster
While high tire pressures may make a bike rider feel fast, generally that's not always the case unless you only ride your gravel bike on paved surfaces. Once past a certain point, excessive tire pressure can reduce grip, increase high-frequency vibration and cause additional muscle fatigue.
Recommended gravel bike tire pressure
Some tire manufacturers offer specific pressure recommendations or calculators for their range of gravel tires based on your weight. These can often be a good starting point.
After the tire is inflated, the actual size needs to be measured. Gravel bike wheel rims vary in width, and you may find that your tire size is narrower or wider than the size noted on the sidewall. If the tire is actually inflated to a wider width, you will need to use slightly less pressure than recommended, and vice versa.
It's also worth noting whether the rim and tire manufacturers set a maximum tire pressure limit, which can usually be found on the rim or tire sidewall. You should not exceed the lower of the two. If you have a set of hookless rims, the maximum allowable tire pressure is likely to be much lower than on clincher (hooked) rims.
The table below lists recommended gravel bike tire pressures for a range of system weights and tire widths. This is based on our experience, tire brand recommendations, and tire calculators.
|Measured tire width||System weight (kg)||Front wheel tire pressure (psi)||Rear wheel tire pressure (psi)|
It's worth emphasizing again that these are just starting points and we encourage actual riding experience to find the gravel tire pressure that works for you. You should check your tire pressure before every ride, as tires can lose air over time.
How to choose the right gravel bike tire pressure?
The above suggestions are intended as a general starting point. Once you determine the right approach, we recommend you start experimenting and consider the following factors to find the right gravel tire pressure for you.
Gravel bike tire and rim width
Determining the actual tire size is critical to calculating optimal pressure.
Although tires are labeled as a certain size, the actual inflation size of any tire will depend on its design and fit within the rim width. Using vernier calipers is the most accurate way to measure tire width.
Rim and tire width also affect the shape of the tire. Wider tires tend to perform better on wider rims. A wide tire on a narrow rim may have a bulb-shaped profile when inflated, while a narrow tire on a wide rim may become too boxy. The pressure needs to be adjusted to suit. For example, a wider tire on a narrow rim may need to be inflated to a slightly higher pressure to prevent the tire from squirming relative to the rim when cornering.
If you're not sure which tire width best matches rim width, the ETRTO 2020 standards are a great place to start.
|Internal rim width (mm)||ETRTO recommended tire width range (mm)|
|21||29 ~ 34|
|23||35 ~ 46|
|25||47 ~ 57|
The tires themselves vary because manufacturers make them differently and use different materials. If you are installing new tires of the same width, you should not automatically assume that the same pressure is optimal.
Rider and system weight
Heavier riders will need higher tire pressures than lighter riders. While the rider accounts for the vast majority of the system's weight, the weight of the bike and any parts or equipment you carry is also important. For example, if you load up your gravel bike and go on a trip, you may need to add more air to the tires.
It is generally recommended to add 2-3psi for every 4.5kg of weight added. As with road bikes, the rider's weight is usually not evenly distributed between the two wheels. Typically, the rear wheels bear a slightly greater load than the front wheels, so the tire pressure on the front wheels is slightly lower.
The terrain you ride on is the biggest factor in determining the best tire pressure for your gravel bike. If you're riding on completely slick surfaces, higher tire pressure may be faster. Conversely, if you're riding on wet, root-strewn off-road trails, you'll need lower tire pressures. Switching to wider tires allows for greater tire volume, improving grip and comfort.
If your riding conditions are mixed with a variety of road conditions, then we recommend that you use medium tire pressure to adapt to different road conditions.
Most high-end gravel wheelsets and tires use tubeless systems.
By eliminating the need for inner tubes, you can have lower tire pressures and reduce the risk of being squeezed and punctured. And lower tire pressure provides better grip and better comfort. It is not recommended to use tire pressures outside the range specified on the tires.
Explosion proof lining
Common in the mountain biking world, run-flat liners for tubeless tires are also starting to become popular in the gravel bike world. If you often have flat tires or are worried about punctures and damage to rims and tires, then it may be a product worth choosing.
You can use it to use lower tire pressures to further improve stability in case of a puncture.
Weather conditions and temperature
When the road is wet, you should consider lowering your tire pressure. This helps increase the contact area between the tire and the road, thereby improving grip.
When environmental conditions become unstable, even a slight drop in tire pressure of 1-2 psi can make a noticeable difference. Most gravel riding involves mixed conditions, so don't just focus on grip in the mud, but also consider performance and safety on other road conditions. If you are doing gravel riding in the winter and the road is icy, the road surface can become very hard. If you have previously used lower tire pressures to cope with muddy roads, you may need to slightly increase your tire pressures at this time.