Come volevasi dimostrare:nel test di bbr gli stessi comfort e scorrevolezza, passando da 25 a 28, si ottengono abbassando la pressione di circa 0.5bar. e' chiaro che scendendo 2.5bar stai privilegiando fortemente il comfort.
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Continental Grand Prix 5000 23, 25, 28, 32 mm Comparison
A detailed rolling resistance comparison of the Grand Prix 5000 in the 23-622, 25-622, 28-622, and 32-622 sizeswww.bicyclerollingresistance.com
Conclusion
A bigger road bike tire (at least the Continental GP 4000 and GP 5000) provides a lower rolling resistance at the same air pressure. You do have to realize that at the same air pressure, a bigger tire will provide a less comfortable ride.
At the 15% tire drop air pressures, which are very close to the recommended air pressures for a given size, the tables are turned and a bigger road bike tire will have a higher rolling resistance. The higher rolling resistance of the bigger tire is because it provides more comfort at the 15% tire drop air pressure.
We feel the ultimate test is adjusting all tires to the same comfort level. When all tires are adjusted to the same comfort level, rolling resistance is nearly the same (0.2 watts max) for all sizes of the GP 5000.
We now feel picking the right size tire is more a matter of looking at what level of comfort (and grip) is required. At some point, a smaller tire isn't able to provide the same comfort level (and grip) as its bigger counterpart because it will start bottoming out.
If you want to go as fast as possible, choose your required comfort level and pick the smallest tire that can provide that comfort for you.





