Why is inflation pressure so important in bicycle tires?
If the inflation pressure is continuously too low, premature tirewear is the result. Cracking of the sidewall is the typical consequence. Abrasion is also unnecessarily high.
Only tires with sufficient inflation pressure can bear the weight of a bicycle. The following applies for the road: The higher the inflation pressure the lower the rolling resistance of the tire. The susceptibility to punctures is also lower with high pressure.
On the other hand, an under-inflated tire absorbs road shocks better.
Wide tires are generally used at lower inflation pressure. The larger air volume is advantageous in that it absorbs road bumps and holes, but does not suffer from higher rolling resistance, less puncture protection or tire wear.
Tubeless tires can also be used at low inflation pressure.
How often should tire pressures be checked?
The inflation pressure should be checked and adjusted at least once a month. Even the best tubes constantly lose pressure as, contrary to car tires, the pressure required in bicycle tires is much higher and wall thickness much thinner. A pressure loss of 10-15 psi per month can be viewed as normal, but pressure loss will be much faster with high inflation pressures and much slower with low inflation pressures.
When using latex tubes, it is best to check and adjust the inflation pressure before every ride.
Use a pressure gauge to monitor the inflation pressure. The widespread thumb-test method is very inaccurate, as all tires will feel identically hard from a pressure of approx. 2 bar up. The thumb test is completely insufficient for Marathon Plus tires due to the special puncture belt.
What is the correct inflation pressure for my tire?
It is impossible to make a general recommendation on inflation pressure for a specific bicycle or a particular tire. The “right” inflation pressure depends mainly on the load exerted on the tire. This weight is mainly influenced by the weight of the rider and any luggage. Contrary to a car, the vehicle weight is only a minor part of the total weight. In addition, there is a great diversity of individual preferences with regard to low rolling resistance or suspension comfort.
The permitted inflation pressure range is marked on the tire sidewall. The higher the inflation pressure, the lower the rolling resistance, the tire wear and the likelihood of a puncture. The lower the inflation pressure the higher are the comfort and grip that the tires provide.
The following list of inflation pressure recommendations can only provide a very general guide for three different rider weights. The more narrower the tire and the higher the overall load, the higher the necessary inflation pressure.
Tires with very small diameters (recumbent bike, folding bike) also require a higher pressure.
But the actual tire pressures should never be higher or lower than the maximum and minimum inflation pressures marked on the tire sidewall.