Gravel bike tyre pressure explained | Recommended pressures and key points to consider

Tyre choice and tyre pressure are the two factors that will have the biggest impact on the performance, control and comfort of your gravel bike.

Tyre pressure is the easiest and cheapest of these two variables to control, and getting the right tyre pressure for your gravel bike will make a huge difference to your ride.

In this guide, we’ll run through why getting your gravel bike tyre pressure right is so important and the factors that can help you find a pressure that works best for you.

While the exact pressure will be specific to every rider, their bike and the trails they ride on, it’s fairly easy to get into the right ballpark.

We asked Vittoria for additional guidance on optimising your gravel bike tyre pressure and have included some of the brand's opinions below.

We've also got guides to road bike tyre pressures and mountain bike tyre pressures.

Recommended tyre pressures for gravel bikes

The are many factors that affect the optimum tyre pressure for gravel riding, but the two most important variables are tyre size and rider plus bike weight.

Generally speaking, wider tyres require lower pressures than narrower ones, while heavier riders – or those carrying loads – will need higher pressures, and vice versa.

The terrain you're riding on, as well as the weather conditions and style of tyre you're using, will also affect the optimal tyre pressure for any given ride, but we'll deal with those factors in greater detail later.

For now, here are some general recommendations based on Vittoria's tyre pressure calculator.

Recommended pressures for 35mm and 40mm gravel tyres

Recommended pressures for 45mm and 50mm gravel tyres

These recommendations are based on what Vittoria classes a 'gravel endurance' style of riding, which prioritises comfort over long distances on varied surfaces, with mixed terrain and weather conditions.

Although these figures are calculated with Vittoria's own range of gravel tyres in mind, they nevertheless offer a good starting point regardless of the brand and model of tyres you're using.

Check out our in-depth guide to the factors that influence optimal gravel tyre pressure below, if you want to fine-tune things further.

It’s also worth noting if there is an upper pressure limit set by the rim and tyre manufacturer, which will typically be found on the rim or tyre sidewall. You shouldn’t exceed the lower measurement of the two.

If you have a set of gravel wheels with hookless rims, the maximum permitted tyre pressure is likely to be limited to 5 BAR / 72.5psi – much lower than is typical with hooked rims – and that the tyres you're using are tubeless-ready and hookless-compatible.

As per the above tables, though, this shouldn't be too much of a worry for gravel riders, because gravel tyre pressures are generally far lower than those used on road bikes.

You’ll also want to make sure you check your pressures before every ride because tyres deflate over time.

• Hookless rims explained | How new standards have finally improved compatibility

Other key points to consider

Before we delve into the details, it’s worth considering why optimising the pressure of your gravel bike tyres is so important.

Why is gravel tyre pressure so important?

Finding the optimal tyre pressure will make your gravel riding easier, more comfortable and you’ll find an increase in grip on all terrain, as well as a reduced risk of puncturing.

Optimising gravel bike tyre pressure is also critical to reducing rolling resistance – how much energy your tyres absorb as they roll.

If your gravel bike tyre pressures are too low, it will take more effort to maintain your chosen speed because more energy will be lost in the deformation of the tyre casing and friction between the tyre and ground.

You also risk potential sidewall and rim damage. The tyre will squirm under you as you ride and if you’re running tubeless tyres, you also risk burping air from the tyre. A burp is where the tyre bead briefly comes away from the rim, expelling air.

Conversely, if your tyre pressures are too high, your tyres will transfer excess vibrations from the road or trail to your hands, resulting in decreased comfort and wasted energy.

Over-inflated tyres also won't deform as effectively when you hit rocks or roots, and the tyre will be more prone to sliding out because it won't have as much rubber in contact with the ground.

Harder doesn't always equal faster

Although high tyre pressures might feel fast, they’re usually not.

Once you go past a certain point, increasing your tyre pressures decreases grip, increases high-frequency vibrations (and therefore rolling resistance) and causes extra muscular fatigue.

Ultimately, tyre pressures that enable your bike to absorb, rather than bounce over, imperfections in the trail will be both faster and more comfortable.

What you’ll need

Ideally, you’ll need a good-quality track or floor pump with an in-built pressure gauge.

You don’t need to spend the earth, but it’s worth investing in the best option you can because it will see a lot of long-term use.

Investing in a tyre pressure gauge is also a smart idea, as Silca CEO, Josh Poertner, says "Your average floor pump has a [pressure] gauge that’s +/- 5 per cent accurate".

Proceed with caution

When it comes to gravel bike tyre pressure, it's best to err on the side of ‘too low’ rather than ‘too high’.

According to testing by Silca, rolling resistance increases rapidly once you go past the optimum pressure for a given setup, and you'll lose comfort and traction on loose surfces, too.

Being a little too low only brings a relatively small speed penalty, but should be noticeably more comfortable and grippier.

Factors that influence optimal gravel tyre pressure

The above recommendations are intended as general starting points. Once you’ve settled on something that’s about right, we recommend you begin experimenting, while considering the following factors to find the right gravel bike tyre pressure for you.

Tyre and rim width

Determining the actual size of your tyres is crucial to calculating optimum pressure.

Despite tyres being labelled a certain size, the actual inflated size of any tyre will depend on its design and the internal rim width of the wheel. Using a pair of digital vernier calipers is the most accurate method of measuring tyre width.

Rim and tyre width also impact the shape of your tyre.

Wider tyres tend to perform better on wider rims, for example, whereas a wide tyre on a narrow rim can appear lightbulb-shaped in profile once inflated. In contrast, a narrow tyre on a wide rim can become too square.

Pressures will need to be adjusted to suit your specific setup – for example, a wider tyre on a narrow rim may need to be inflated to a slightly higher pressure to prevent it from squirming when cornering.

If you’re unsure of which tyre and rim widths are best matched, the ETRTO 2020 standard makes for a good starting point.

Tyre type

Since manufacturers use different construction methods and materials to make their tyres, optimal inflation pressures can vary depending on the type and model of tyres you have.

Given this, if you're fitting a new tyre of the same width, you shouldn’t automatically assume an identical pressure is optimal.

Vittoria, for example, makes tyres with sport, endurance and race casings, as well as with a number of different tread types.

It uses its Gravel Terrain Score (or T-Score) system to help riders pick the best gravel tyre for their needs.

As with road tyres, gravel tyres with thicker, tougher casings might need a little less air in them than lightweight, supple tyres designed for racing.

Rider and system weight

A heavier rider will need to run a higher pressure than a lighter rider.

However, while the rider makes up the vast majority of the system weight, the weight of your bike and any kit or equipment you’re carrying also count.

For example, if you’ve loaded your gravel bike up with bags to go on a bikepacking trip, you may need to add more air to your tyres.

The easiest way to an accurate figure out your total system weight is to get a set of bathroom scales and weigh yourself with your kit on, and while holding your fully loaded bike.

Then you'll be able to plug the exact number into Vittoria's calculator and get recommended tyre pressures for your bike.

As with road bikes, the rider’s weight is generally not distributed evenly across both wheels.

It’s usually the case that the rear wheel takes slightly more load than the front and, as such, you’ll want to run a slightly lower pressure in the front tyre.

Terrain

While it's less important than rider plus bike weight, the terrain you plan to ride on also impacts optimal tyre pressure.

If you’re riding on perfectly smooth gravel, then slightly higher pressures could be faster. Conversely, you’ll want to run much lower pressures if you’re riding on wet, rooty off-road trails.

Here are some example tyre pressures for various terrain types. These are based on an 85kg rider plus bike weight, with 700x40c / 40-622 tyres and a mix of wet and dry conditions.

If you're riding on rough trails, switching to wider gravel tyres can also give you a larger volume of tyre to play with, and you’ll have increased grip and comfort.

Many professional gravel racers have even turned to cross-country mountain bike tyres in recent years, as some believe them to be faster than narrower gravel-specific tyres when riding off-road.

• Why XC mountain bike tyres are gravel racing's hottest pro trend

Tubeless

Most high-end gravel bike tyres can be run tubeless, but you'll need to ensure your wheels are tubeless-ready before ditching your inner tubes. You'll also need some tubeless valves and sealant, if you don't already have them.

Without inner tubes, you can run lower pressures with a lesser chance of pinch-flatting, and improved comfort and grip.

Small punctures can also be self-sealed by the tubeless sealant, which is a boon for riding off-road, where tiny sharp objects are typically harder to spot while riding.

Even if you do switch to tubeless, though, we'd still recommend carrying a couple of spare butyl or TPU inner tubes in case you get a puncture that won't self-seal or can't be plugged.

• How to set up a tubeless tyre without the mess in 5 simple steps

Tyre inserts

Common in the mountain bike world, tubeless tyre inserts for gravel riding are starting to become popular.

Typically made from lightweight, low-density foam, tubeless tyre inserts help protect the rim from impact damage, reduce the likelihood of air burping and provide extra sidewall stability when running low pressures.

They can also offer the ability to continue riding on a punctured tyre until its safe to stop and repair it.

Inserts could therefore be a worthwhile proposition if you’re regularly flatting or are worried about damaging your rims or tyres while riding.

Downsides typically include slightly increased weight (around 45g per tyre for Vittoria's Air-Liner Light Gravel in a 700c x 42-50 size) and rolling resistance, although most brands claim these factors have a negligible effect on performance compared to the benefits.

Perhaps more importantly, running inserts means you won't be able to pop in an inner tube in the event of a puncture (unless you're willing to remove it and carry it home bandolier-style), so you'll need to rely on tubeless repair kits instead.

• Do you run tubeless tyres? This is what to do if your tyres fail

Weather conditions and temperature

When the trails are wet, you should consider dropping your tyre pressures. All else being equal, this helps increase the amount of rubber contacting the trail, thus improving grip.

Vittoria recommends dropping your pressures by roughly 0.1 bar or 1 psi when going from dry to wet conditions, for example.

It's worth remembering that many gravel rides feature a mix of conditions, however, and it's not possible to optimise for every specific thing.

Given this, we'd generally recommend erring on slightly too low rather than slightly too high, for the reasons we noted earlier.

These recommendations are again based on a total system weight of 85kg, with 700x40c / 40-622 tyres. This time, though, we've assumed mixed terrain.

As with all of the recommendations in this article, they're best seen as starting points for individual experimentation and we'd advise fine-tuning your own tyre pressures based on your needs and riding style.