English to Italian Other Sports / Fitness / Recreation

Resistance is one of the reasons why some objects move more slowly than others. However, there are different types of resistance, such as the frictional resistance between a tire and the road surface. If you want to ride as fast with a mountain bike tire as with a road racing tire, that's quite a tough task. That’s logical since the wide MTB tire with its coarser tread will cause more friction than the smooth road racing tire.

The air also causes resistance. When you ride, you 'collide' with air and it is pushed aside so that it can 'flow' around you. If you ride faster, the air will have trouble getting around you as quickly and jumping into that void behind you. Then 'negative pressure' arises. That's literally a zone that will slow you down.