How exactly do the different gears on a bike change how easy it is to pedal? And why is it that despite being at the appropriate gear, it is still harder to climb uphill despite the same pedals per minute?

Question

How exactly do the different gears on a bike change how easy it is to pedal? And why is it that despite being at the appropriate gear, it is still harder to climb uphill despite the same pedals per minute?

In: Physics

Answer 1

One issue going uphill is that if you try to remain seated your body position changes to adjust to the bike slope vs gravity and your muscles aren’t working as effectively because your at sub-optimal positioning. Moving to standing helps some, but unless you’re going fairly slow this also adds air resistance.

The other issue going uphill – cycling works as well as it does because on flats there is relatively little resistance to overcome until you’re going pretty fast. The required work rate to go at a decent running speed is very low. Once you’re fighting gravity also the work rate to maintain the same speed increases dramatically, so you have to slow down a lot more than you’d expect for a hill climb.