What are the recommended tyre pressures for the best performance on road tyres?
Tyre manufacturer's pressure recommendations must be observed. Never exceed the maximum pressure of the wheel or tyre (whichever is lowest) and make sure that any minimum pressure requirements that the tyre manufacturer states are also met. Failure to do so will not only compromise your performance on the bike but could be a safety risk.
You should bear in mind other variables and tweak the pressures to suit you, your riding style, terrain, specific tyres, and bike:
- Rougher surfaces may require a slight reduction in pressure on the road to increase comfort, but off-road the pressure may need to be increased to protect the rim and tyre from impacts.
- Adding load to you or your bike may require some slight extra pressure in the tyres.
- Some tyres, such as those with added protection from punctures with heavy-duty sidewalls, can be stiff and require slightly lower pressures.
- Remember the same tyre in different usage scenarios can have differing maximum tyre pressures e.g. tubeless may be lower than tubed and if used on a hookless rim may be lower again.
- Observe all pressure recommendations given by the tyre manufacturer and never exceed the maximum pressure of the tyre or the rim, whichever is the lowest.
- Ensure that an accurate pressure gauge is used when checking your tyre’s pressure, be aware that the gauges on some pumps can be inaccurate by a high percentage.
When choosing a tyre model and size make sure it is compatible with your rim. This includes, but isn’t exclusive to - tubeless compatibility, hookless compatibility and rim width.
Precautions for rim braking on long descents, especially in hot weather
Key information regarding tyre and rim heat build-up during long periods of rim braking:
- As rim braking is undertaken your kinetic energy is dissipated through heat between the brake pads and rims. This heat is then transferred to the air and tyre which are in contact with the rim.
- The longer and heavier the braking the more heat is dissipated into the tyre.
- Warm days obviously accentuate this problem as all components are warmer to begin with, and they are less able to conduct the heat away as the differential in temperatures is much lower between air and tyre/rim. Hot road surfaces will also add to the problem.
- As heat builds in the tyre, the air temperature in the inner tube/tyre rises and hotter air expands, this increases air pressure. If this continues it can reach levels that that tyre/inner tube is no longer able to cope with and thus they fail. A tubeless tyre can suffer the very same issues.
This is an issue that rim-braked bicycle wheels of all kinds are susceptible to, and thus there are some reasonable precautions you should follow:
- Long descents and heavy braking carry inherent risks due to heat build-up on the braking surface, especially in hot weather. It is advisable, on all clincher or tubeless tyre systems, to drop your tyre pressure by 10psi from your normal setting. Please ensure you remain within the recommended pressure by the tyre manufacturer. This will improve grip and resistance to high- tyre pressures due to heat build-up from braking.
- Stop regularly during long & steep descents to allow your brakes to cool. If you suspect your rims are reaching high temperatures during braking it is essential to stop riding for a period and allow them to cool before you continue. This is a reasonable and sensible action that all wheel, tyre and bike manufacturers would suggest.
Did you find it helpful?Send feedback