Road bike tyre pressure
Too high and it feels like you’re riding on huge rocks all day, and corners feel like ice rinks.
Too low and you risk getting pinch flats, you wear your tyres out, and it feels like riding through mud.
But if you get the perfect pressure in your bike tyres you’ll be faster, smoother, and have better grip!
Every rider has an ideal best pressure for them
It’s about finding a balance between speed, ride quality, and puncture resistance that suits your preferences and the nature of your ride (for example, you have different requirements between a road race and a bike packing trip).
But don’t worry, finding the right pressure for your bike tyres isn’t complete guesswork: there are a number of things you can bear in mind that will get you in the right rough area to start with, and you can then adjust from there.
The first two key things to consider are bike and rider weight, and tyre selection.
Rider and bike weight
When you sit on a bike, your mass causes the tyres to compress or ‘squidge’ a small amount. The heavier you and your bike are, the greater that compression. As such, a heavier rider will run higher pressures than a lighter rider for a similar amount of tyre compression.
You need to find the optimal compression in the tyre – if it compresses too little, the bike tyre will not sit well on the rim and increase the risk of pinch flats. If the bike tyre doesn’t compress enough, the contact patch between the road and the rubber will be so small that you risk losing grip on corners and descents.
And remember, if you don’t normally ride with a lot of luggage on your bike and then load it up with frame bags, you need to adjust the pressure. A rule of thumb is that one extra kilo of mass (from both the bike and the rider) equates to a 1% increase in tyre pressure. So, if you normally ride at 100psi and add a 5kg bag to your bike, you want to run a pressure of around 105psi in your bike tyres.
One key thing to remember is, no matter how heavy you and your bike are – don’t exceed the maximum pressure recommendation on the tyre. This number will be printed on the sidewall of the tyre, and probably on the packaging you received when you bought it. Exceeding the recommended pressure could lead to tyre blow outs or the tyre popping off the rim – which could be disastrous if it happens mid-ride.
Not that long ago, it was normal for roadies to ride on 23c tyres, now, the norm is 25c or even 28c. The trend toward larger tyres has largely been due to the fact that wider rubber is more comfort!
A wide bike tyre can accommodate more air inside it than a skinny tyre – there is more ‘space’ inside the rubber. This means that you can run a lower pressure inside it without incurring the risk of a pinch flat, something that is caused when the inner tube gets pinched between the rim and road surface.
Running a wider tyre at a lower pressure offers two major bonuses over using a narrow, highly inflated bike tyre:
COMFORT: You get the puncture protection of a highly inflated skinny tyre, but with more comfort – the lower pressure inside a wider bike tyre will absorb the imperfections in the road a lot more easily.
SPEED: Although a less-inflated, wider tyre increases the contact area with the road versus a skinny, highly-pumped bike tyre, they will have the same rolling resistance, which affects your speed. This is because a softer tyre will absorb road shocks, meaning impacts aren’t transferred up to the rider and – so you can ride smoother.
You shouldn’t be running the same pressure in your bike tyres in the wet as you would in the dry. If the roads are wet and greasy from falling rain or showers that fell soon before your ride, you need to slightly drop the pressure you would normally use. This will increase the contact patch between the tyre and the tarmac, giving you better grip.
Don’t go too crazy with how much you drop the pressure though – a reduction of around 5-10psi (0.3-0.6 bar) should be sufficient.
Although this guide is generally aimed at road riding, if you’re taking your road bike on a route involving a bit of gravel or harsh cobbles, you need to reduce your bike tyre pressure slightly. This will help absorb the impacts in the road and give you a smoother ride and better traction.
As with the example regards wet weather, don’t drop the pressure too far, or you risk getting pinch flats. Again, aim at around 5-10psi (0.3-0.6 bar).