So in the just finished Tour de France in some of the last stages in the mountains, they talked about a hill climb of 9 percent. I assume horizontal, neither going up against gravity or downwards, would be zero percent climb, I expect. But what is 100 percent? Straight up, that is to say, 90 degrees from horizontal?

If so, then 50 percent would be 45 degrees? 5 percent = 4.5 degrees? 1 percent=0.9 degree? 1 percent = 54 minutes? 9 percent climb = 8.1 degrees?

If so, just what is the utility in that where they could just say, it's an 8 degree climb?

Are we supposed to be so dumb we can't figure out what 90 degrees is?

Originally posted by wolfgang59 you would have to use a bit of trig if you were measuring distance travelled as i believe the ratio you want is (vertical change)/(horizontal change)

No, he is correct, it is the ratio of elevation change to distance traveled.

Originally posted by forkedknight No, he is correct, it is the ratio of elevation change to distance traveled.

Going to that wiki link that you recommended shows that 100% is 45 degrees, which confirms that the ratio in question is 'vertical change':'horizontal change' and not 'vertical change' : 'distance travelled'

Your definition would be more useful but it is not correct.

Originally posted by wolfgang59 Going to that wiki link that you recommended shows that 100% is 45 degrees, which confirms that the ratio in question is 'vertical change':'horizontal change' and not 'vertical change' : 'distance travelled'

Your definition would be more useful but it is not correct.

But his statement, driving 10 miles up a 10 % climb puts you 1 mile in the air is wrong because 'driving 10 miles' is actually the hypotenuse of the resultant triangle? So that ten mile drive would actually be covering somewhat less distance of horizontal travel?

I guess you would have to do the a squared plus b squared deal to get the actual distances right, eh.