Gone are the days of simply pumping up your road bike tyres to the maximum pressure permitted and hoping for the best. Not only are excessively high pressures uncomfortable, they’ve also been proven to slow you down.
Equally, for beginner cyclists, it’s not always clear what pressure you should pump your tyres up to. While most tyres have a recommended pressure range printed on the sidewall, there’s rarely any more guidance than that.
Ultimately, the pressure you need to run will vary depending on the rider, bike and road conditions, but it’s fairly easy to get into the right ballpark. Whether you’re just starting out or you’re an experienced rider looking to optimise performance, we’re here to help.
So, how can you find the right tyre pressure for your bike? In essence, it’s all about finding a balance.
You need your tyre pressure high enough to minimise energy losses from the deformation of the tyre and to offer predictable handling through corners. But you also need it low enough to absorb, rather than bounce over, imperfections in the road.
In this article, we’ll run through why tyre pressure is so important, what factors influence finding your optimum pressure, and how you can find a pressure that works best for you.
If you’re just starting out, we’ve also got an explainer on how to pump up a bike tyre, as well as a guide to inner tubes, with everything you need to know about tube sizes, valve types, materials and so on.
Key points to consider
Before we get stuck into the details, here are four key things to consider when it comes to road bike tyre pressure.
On a basic level, getting your tyre pressure right will make your rides easier, more comfortable and lower your chances of punctures.
From a performance standpoint, optimising tyre pressure is critical to reducing rolling resistance and improving comfort. Rolling resistance is the force resisting the motion of your tyres rolling on the ground.
If your tyre pressure is too low, more energy will be lost in the deformation of the tyre casing and friction between the tyre and the road. It also increases the chance of pinch flat punctures.
If your tyre pressure is too high, the tyre will be so stiff your bike will begin to vibrate over imperfections in the road surface, negatively affecting comfort and wasting energy.
What feels fast, might not be fast
Very high tyre pressures might feel fast, but they’re not.
Once you go past a certain point, adding more air to your tyres actually decreases grip, increases high-frequency vibrations and causes extra muscular fatigue. All of these things slow you down.
Getting your tyre pressure right is both faster and more comfortable.
Tools for the job
In order to set the right tyre pressure on your road bike, you’ll ideally have access to a track or floor pump with an in-built pressure gauge. You don’t need to spend loads, but given how much you’ll use it in the long term, getting something high-quality makes sense.
If you really want to fine-tune your tyre pressures, one of the best tyre pressure gauges is a worthwhile investment, too.
Proceed with caution
When it comes to road bike tyre pressure, err on the side of ‘too low’ rather than ‘too high’.
According to testing by Silca, performance decreases rapidly once you go past the optimum pressure for a given setup. Being a little too low only brings a relatively small speed penalty, but should be noticeably more comfortable on rough roads.
Recommended tyre pressures
Helpfully, some tyre manufacturers offer pressure recommendations or pressure calculators for their range of road bike tyres, and we can take these as general starting points for dry days on smooth tarmac.
As we’ll come on to, you should pay close attention to the actual size of your tyres when inflated because this can change optimum pressure for any given rim and tyre combination.
If the actual inflated tyre width is larger than the labelled width, the tyre will need slightly less pressure than recommended by these tables and vice versa.
Likewise, the optimum tyre pressure will be higher for heavier riders, or for riders carrying loads on their bikes, and lower for lighter riders.
As a final caveat, it’s important to adhere to the pressure limitations set by the manufacturers of both your rims and tyres, particularly with regards to the upper limits. These are typically printed on the tyre or rim sidewalls.
If you have a set of wheels with hookless rims, the maximum permitted tyre pressure may also be much lower than with hooked rims.
Tyre pressure for 23mm and 25mm tyres
The following recommendations are from Pirelli for its TLR tubeless road tyres, but are good starting points regardless of the brand of tyres you’re using, providing you take the various factors we’ll run through later into account when going on to fine-tune tyre pressure.
Tyre pressure for 28mm and 30mm tyres
Advice from other brands may vary, but Pirelli recommends riders who weigh over 96kg / 212lb should use 700 x 25c tyres or larger because the recommended tyre pressure for a rider of this mass would exceed the maximum permitted pressure for a 700 x 23c tyre.
As always, it’s vital not to exceed the maximum pressures indicated on your tyres or rims.
How do Pirelli’s recommendations stack up against what tyre pressures I personally use? Let’s have a look at some examples.
To give these pressures some context, I weigh around 63 to 64kg.
Given most time trials tend to take place on fairly good roads without too many potholes, I run around 90psi front and rear.
However, on my Giant TCR Advanced Pro 2, I’d typically be running 28mm tyres on 19mm rims. For this, I’d normally use pressures of around 65psi because the roads I ride on most often tend to have rough or broken surfaces.
Do you ride a mountain bike?
Getting your tyre pressure right on a road bike is very different to a mountain bike, where tyres (and wheel rims) are significantly wider, the terrain is looser and you have trail obstacles to contend with.
If you ride off-road, we’ve got a separate guide to mountain bike tyre pressure.
Factors that influence optimal tyre pressure
As already noted, the above recommendations are intended as general starting points. They’ll get you in the right ballpark, but there are a number of factors beyond tyre and rim size and rider weight that affect your personal optimum road bike tyre pressure.
Accurately determining your tyre size is crucial to calculating optimum pressure.
Despite most bicycle tyres being labelled with a specific size, such as 700 x 25c, the actual inflated size of any given tyre will depend on both the design of the tyre and the internal rim width of the wheel.
Most new tyres are now designed around the latest 2020 ETRTO (European Tyre and Rim Technical Organisation) standards with a 19mm internal width, so wheels with an internal rim width wider than this will likely increase the measured width of a tyre when inflated to a given pressure (and vice versa).
The optimum pressure is, therefore, likely to be lower than if you were running the same tyre on a narrower rim.
System weight and weight distribution
While the rider makes up the vast majority of the total system weight – and, as we’ve already covered, a heavier rider will generally need to run higher pressures than a lighter rider – the weight of your bike and any kit you’re carrying also count.
If you’re riding a sub-4kg weight weenie optimised road bike and don’t have it loaded up with heavy gear, then you might need to lower your tyre pressure by a few psi.
With road bikes, the rider’s weight is generally not evenly distributed across both wheels. The exact split will be different for every rider, depending on riding position and bike, but it’s usually the case that the rear wheel takes slightly more of the load than the front.
As a rule of thumb, it’s worth putting a few psi less in the front tyre than in the rear.
If you’re riding on a perfectly smooth velodrome, higher pressures are faster. However, on imperfect surfaces, such as roads, very high pressures simply increase vibrations and can slow you down.
As roads get rougher, with bigger holes and bumps, the optimum tyre pressure decreases further.
When roads get very rough, smaller tyres (anything 25mm or smaller) running at a relatively low pressure may not be able to provide enough protection for the rim or inner tube – especially for heavier riders – which can lead to pinch flats or even rim damage.
Switching to larger tyres will give you a greater amount of tyre volume to play with, so you can fine-tune the pressure to account for both rolling resistance and comfort on rough roads.
Weather and temperature
When road surfaces are wet, or if it looks like it might rain during your ride, it’s worth dropping pressure by around 5psi on both tyres. This helps increase the amount of rubber in contact with the road, which should improve grip.
Higher temperatures, whether ambient or induced by rim braking, can also increase tyre pressure.
If you’re riding long descents on hot summer days on a bike with rim brakes (particularly one with carbon clincher wheels or latex inner tubes), be careful to not over-inflate your bike’s tyres. Doing so could lead to dangerously high pressures building up inside the inner tubes or tubeless tyres, if too much excess heat is introduced to the system.
The materials and construction methods a road bike tyre manufacturer uses can also affect the optimum pressure, to a small degree.
Road bike tyres designed for racing or summer use tend to have casings that use a higher number of thinner nylon or cotton threads (this is what the Threads Per Inch or TPI number of a tyre refers to), and only a thin layer of rubber tread on top. This makes them easier to deform under pressure, making for a smoother and faster ride.
Conversely, winter road bike tyres typically have stiffer, more durable casings with fewer, thicker nylon threads. The rubber tread on top also tends to be thicker for improved mileage and puncture protection.
Given this, you may need to drop your road bike tyre pressure slightly when moving across to winter tyres because the optimum pressure for comfort and grip is likely to be a few psi lower.
If you’re using tubeless tyres, it’s worth remembering that the absence of an inner tube means you can safely run lower pressures without the risk of pinch flatting the tube.
Because lower tyre pressures can improve off-road grip, running tubeless tyres can be particularly useful if you’re riding a road bike with relatively large tyres and looking to take in some light off-road or gravel riding.
Fine-tuning road bike tyre pressure
So, you have all the information at your fingertips, but how do you actually go about fine-tuning tyre pressure? The simple answer is experimentation.
Start with the recommendations above and then consider what the road conditions are like where you ride. Do you have miles and miles of freshly laid tarmac? If so, the above recommendations are probably close to optimal.
If you don’t – perhaps because you live somewhere such as the UK – start with the above recommendations and experiment with taking a little pressure out of the tyres each time you go for a ride.
Start with small steps in pressure of around 5psi, and, if you pay attention, you should eventually be able to determine a sweet spot for speed and comfort.
You’re looking for a pressure that feels smooth, without feeling like the tyre is collapsing underneath you when cornering. And, as already mentioned, erring on the side of too low rather than too high is a good thing to keep in mind.
Alternatively, if you have an accurate and reliable power meter, you could do some basic field testing yourself.
Find a long, steady climb with an average gradient of over 5 per cent, and see how different tyre pressures affect the power required to ride at a certain speed, or how fast you travel for a set power output.
The data you acquire should enable you to hone in on an optimum tyre pressure for the setup and road conditions you’re using when testing.
You’re looking for the tyre pressure that requires the least power for a set speed, or enables you to travel fastest for a set power.
As with any testing, it’s important to keep all other variables (e.g. system weight, riding position, traffic, weather, etc) the same for each test run, otherwise, you can muddy the results.