Road bike tire 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 tires out, and it feels like riding through mud.
But if you get the perfect pressure in your bike tires 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 tires 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 tire selection.
Rider and bike weight
When you sit on a bike, your mass causes the tires 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 tire compression.
You need to find the optimal compression in the tire – if it compresses too little, the bike tire will not sit well on the rim and increase the risk of pinch flats. If the bike tire 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 tire 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 tires.
One key thing to remember is, no matter how heavy you and your bike are – don’t exceed the maximum pressure recommendation on the tire. This number will be printed on the sidewall of the tire, and probably on the packaging you received when you bought it. Exceeding the recommended pressure could lead to tire blow outs or the tire 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 tires, now, the norm is 25c or even 28c. The trend toward larger tires has largely been due to the fact that wider rubber is more comfort!
A wide bike tire can accommodate more air inside it than a skinny tire – 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 tire at a lower pressure offers two major bonuses over using a narrow, highly inflated bike tire
COMFORT: You get the puncture protection of a highly inflated skinny tire, but with more comfort – the lower pressure inside a wider bike tire will absorb the imperfections in the road a lot more easily.
SPEED: Although a less-inflated, wider tire increases the contact area with the road versus a skinny, highly-pumped bike tire, they will have the same rolling resistance, which affects your speed. This is because a softer tire 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 tires 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 tire 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 tire 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).