Because gravity makes your bike (that is also carrying your entire body weight) want to roll back down the hill. The wheels make it so that it’s easier to move with the same force, and on even ground, that’s a good thing – the same amount of effort will take you way farther when pedaling than walking. But that also means the force of gravity is way more efficient at pulling it back. Walking up a hill means pulling yourself up step by step, but you don’t have that force acting on you in the same way.
Latest Answers