Still, for most riding conditions, the rear tyre takes generally more load. On road bikes, when a rider is leaned all the way forward, load distribution of front – to rear wheel is about 45% – 55%. That is why the front tyre shouldn’t be much softer than the rear tyre.
In case of hard braking, or hitting a kerb, the front tyre takes the same load as the rear tyre, at least temporarily. This is the optimal rear tyre pressure.Īfter the optimal rear tyre pressure was determined, it is time to adjust the front tyre pressure. The pressure at which there is a 15% drop depends on the load and tyre width. First, the tyre is inflated/deflated to achieve the 15% drop.
If it deforms too much, the pressure is too low. If it doesn’t deform at all, the pressure is too high. This can be measured visually – no need to use a ruler. The tyre should just slightly “bulge” at the place it contacts the ground. The drop of a loaded tyre at the point of surface contact Then it is measured how much the rear tyre is compressed compared to its height when the bike is completely unloaded. Then, the bike is loaded with luggage that it’s supposed to carry (if any). What does this mean? Let me explain.įor a short “rough” recommendation, see chapter 3.3įirst, both tyres are inflated to be firm (feel by squeezing with a hand). The optimal pressure of the rear tyre is a 15% drop. allowed pressure, you should look for wider tyres, or at least some higher quality ones of the same width (see which tyre widths fit which rim widths). If the optimal tyre pressure, determined as explained in the remainder of this post, exceeds the tyres max. To what pressure should I inflate my bicycle tyres?īicycle tyres usually have the maximum allowed pressure they can take written on their sidewalls. The more volume a tyre has, the less air pressure is needed for it to carry the same weight.ģ. With width increase, tyre volume increases significantly. On the other hand, a tyre with the same diameter, but 47 mm wide (622-47) is inflated to pressures below 4 bars – for the same weight carried. The bigger the weight carried by the tyre, the higher the pressure is required.Ī typical example is a tyre with dimensions 622-23 (23 mm wide) that is inflated to pressures over 7 bars. The bigger the air volume (larger wheel and/or wider tyre), the lower the pressure required. This enables it to comply with terrain irregularities, making the ride comfortable and grip better. Tyre deforms in place it contacts the surface, when it is loaded. Optimal tyre pressure is the one that allows the tyre to carry the weight without deforming too much, but so that the tyre is not too hard, making the ride harsh, and traction poor.
#4.5 BARS TO PSI FULL#
When there’s no load pushing it against the ground, it stays at full height, the air pressure inside keeping it stretched.
The height of the tyre is about the same as its width. Absorbing road irregularities (bumps, holes etc.).Enough rigidity and firmness to allow good control and steering.Tyres are filled with air in order to achieve several effects at the same time: What is the role of air pressure in tyres? Bicycle tyre pressure recommendations tableġ. To what pressure should I inflate my bicycle tyres?ģ.3.What does the optimal tyre pressure depend on? What is the role of air pressure in tyres?Ģ.1.This post answers a frequently asked question: “To what pressure should I inflate my bicycle tyres?” Related posts explain: “ Slick bicycle tyres,” “ Rolling resistance – are narrower tyres faster” and “ Bicycle winter tyres.”
0 kommentar(er)
