nubikebuzz

I'm just curious about other's impressions.

How would you best describe the relationship between slope and the effort involved to climb it? In other words, as slope increases, how much does effort increase?

In your opinion is the relationship linear, logarithmic, exponential, etc.?? Has anyone studied this?

I've tried searching the forums and nothing comes up. Sorry if I missed it.

Pat

Well, I have climbed things up to and slightly over 20%. It is a matter of one's power/weight ratio, the gearing one has and the steepness of the slope.

It would also depend on how one measures "slope". There is percent grade where a 1:1 slope is 100% and degrees where a 1:1 is 45%.

For one person, a 4% grade might seem REALLY steep. Another person, that would be 7%. For someone else, it might be 14%.

Also there is the speed one is going. It really does not take much of a slope for it to get pretty brutal if you are with a group that is really pushing the pace. On the flats, one gets a big advantage by drafting. The drafting advantage declines really quickly even on a modest grade.

Think about it, as the slope increases, one can manage it by slowing down a mite and lowering the gearing. But once you are out of the saddle and in your lowest gear, that is all your equipment will do for you. From then on out, climbing has to be all grit your teeth and do it. For any rider, there is a slope that you just can not do period. Now with really strong cyclists, there probably is not a road in the country that steep. I think the maximum grade that roads get is something just over 33% or so.

Shimagnolo

Plug in the numbers, and see for yourself: https://www.analyticcycling.com/ForcesPower_Page.html

Be aware that the slope used is rise/run, and *not* percent. i.e. 3% is entered as 0.03 here.

nubikebuzz

Thanks for that link. That's the sort of info I was looking for.

gregf83 

If you have access to a powermeter and the right gearing the slope impacts your speed only not your effort. For example if you know you can generate 300W for an hour or so and you come to a hill that would take an hour to climb you just keep your power around 300W until you reach the top. It won't matter what slope the hill is provided you have the gearing available to ride at a comfortable cadence.

Of course, if you're too heavy, there will always be a slope where you don't have the right gearing and the climb will become painful or unmanageable but that is a function of your power/weight ratio.

colombo357

Theoretically, it's linear without taking wind resistance into account. Climbing a 10% grade requires twice as much energy to move at the same speed as climbing a 5% grade. Also, at the same speed, climbing the 10% grade will allow you to achieve the same elevation gain twice as fast (obviously).

In a real world scenario, you ride faster when climbing the 5% grade. The resulting increase in wind resistance makes it so that it actually takes more energy to achieve the same elevation gain, despite the lower perceived effort.