Comparing Ascent and distance


New Member
Sorry, I can't understand your ascent.


Forum Stalwart (won't take the hint and leave...)
Using Jimbolee's type of calculation:
Assuming a casual speed of 10 mile/h, the first run would take 3 hours, resulting in an increase in height of 914m. Assuming a 100Kg man and bike, taking gravity as 10m/s² (calc is very rough), power output would have to be 84 watts, just to get the bike uphill. Add rolling resistance and wind resistance to that to get to the required human power output.

The second example requires a much lower power output - only 610m is gained in height, and this takes 4 hours, resulting in a power output of 42 watts.

The difference is (from the suggesting in the original post) how long can that sort of power be delivered by a human. I don't have Jimbolee's graphs to hand, but a quick search on Google delivers:
200 watts for about 1 hour continuous.
100 watts for about 5 hours continuous.
For fit male cyclists in their middle years, 25 to 50 approximately.
Remember that this is a log ratio, so 3 hours continuous is not 150 watts, but instead much nearer the 100 watts level.

Hence, ignoring the effect of wind resistance, the second option is by far the easier.

Assuming wind resistance is important, if the first route used 26 watts against resistance (to make up a round 100 watts), the second route would require a power output of 68 Watts to achieve the same speed, but less climbing - well within the loss of power output required to pedal for a further hour.

Any questions?


Bird Saviour
Route 1. definitely. i pretty much do the other one when i commute and i would hate it if it was more hilly! even if it was shorter.


Nr Cambridge
Total elevation climbed usually makes more difference than distance traveled. That said if you're riding along & keeping to a perceived exertion level then distance is what you'll notice.
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