Pedalling up a hill. Which is more efficient?

[FluffyBob]

@Richard_Pearse

If you suck at riding up hills, lose weight and get stronger! Other than that, if you want to ride lots of hills or long hills in one ride, go up at a sustainable cadence and speed. Personally I like to have a cadence around 90 rpm and my height rate somewhere around 165 bpm which is about 90% of my max. With those numbers I can climb hills all day and it doesn’t “take forever to crest the hill”. For me it is both the fastest way to get up a hill and the most sustainable way. If it is a short hill of only say half a kilometer then I might stand and sprint up, but in so doing I’m burning energy that I don’t get back over the ride and I can only do it a certain number of times. If, having spun up the hill in a sustainable way, I find myself close to the top and feeling good, then I might sprint the rest of the way.

This. An experienced cyclist in good training will have conditioned his body to use the bike in its most efficient manor. To a novice a cadence of 90 may feel too fast, where to a good cyclist it is just cruise. Also you are already at premium cruise if you are on the flats anyway, if you need to pour on the juice before the hill you have been slacking.

[RedSwinglineOne]

@newme

Air resistance is proportional to the square of the velocity. Much of the energy used to speed you up is wasted in pushing the air out of the way faster.

Velocity cubed I believe.

@DSeid

The ideal answer for efficiency is that you should be geared so that you are making as consistent an effort (be it by heart rate or percieved effort) throughout the downhill and uphill portions as possible. That will be fast on the flat and slower going up

That’s why I started riding singles. I got tired of feeling like a hamster on a treadmill, always riding with the same cadence and effort. You have to earn your way up a hill on a single.

[Princhester]

@RedSwinglineOne

Velocity cubed I believe.

You are probably confusing air resistance and the power required to overcome it. Air resistance is proportional to the square of the velocity, but the power required to overcome air resistance is proportional to the cube of the velocity.

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