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Discussion Starter · #1 ·
* Km 31.0 - Côte de Sainte-Marguerite - 3.5 km climb to 6 % - Category 3
* Km 79.0 - Col du Galibier - 20.9 km climb to 5.6 % - Category H
* Km 156.0 - Col de la Croix de Fer - 29.0 km climb to 5.2 % - Category H
* Km 210.5 - ALPE-D'HUEZ - 13.8 km climb to 7.9 % - Category H

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Anyone know what's the meaning of 20.9 km climb to 5.6% ??
5.6% from what ??

The 20.9 km is the distance, but 5.6% is ???

Thanks
 

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That's the average gradient of the climb....so 5.6% means the climb averages a 5.6% grade for 20.9Km. It may get steeper or shallower on parts of the climb, but the overall average is 5.6% for that one particular climb.
 

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Wookie is spot on with his answer, but just to go into a bit more detail, the grade can be looked at in a couple different ways, but in the end it is the percentage of elevation gain over distance.

A climb with a 5.6% grade for 20.9 km would climb 1170.4 meters or 3,840 feet.

Another way of looking at it would be that on a 5.6% climb, you'd be climbing about 1 foot for every 17.5 feet traveled. 5.6% isn't terribly steep but in the case of the Galibier, the average is lower because the first 10km are fairly easy where as the last 10km are much harder.
 

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Discussion Starter · #5 ·
gray8110 said:
Wookie is spot on with his answer, but just to go into a bit more detail, the grade can be looked at in a couple different ways, but in the end it is the percentage of elevation gain over distance.

A climb with a 5.6% grade for 20.9 km would climb 1170.4 meters or 3,840 feet.

Another way of looking at it would be that on a 5.6% climb, you'd be climbing about 1 foot for every 17.5 feet traveled. 5.6% isn't terribly steep but in the case of the Galibier, the average is lower because the first 10km are fairly easy where as the last 10km are much harder.
Thank you very much for the detail...

So if I climb for 5km with the altitude 700m
The gradient is 700m / 5000m is 14%....?

Anyone know the good altitude and distance computer ? maybe from cateye ?
 

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bianchi77 said:
I must have the distance measurement and the altitude measurement for knowing the gradient ?
Correct - you need distance and the elevation gained in that distance to know the grade. To calculate it you would divide the elevation gained by the distance.

There are many good computers with elevation data out there, but I can't point to a specific one.
 

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gray8110 said:
Correct - you need distance and the elevation gained in that distance to know the grade. To calculate it you would divide the elevation gained by the distance.

There are many good computers with elevation data out there, but I can't point to a specific one.
You need horizontal distance travelled not actual riding distance. If you use actual riding distance, you'll underestimate the slope a bit. The steeper the slope, the greater the underestimate.
 

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gray8110 said:
Correct - you need distance and the elevation gained in that distance to know the grade. To calculate it you would divide the elevation gained by the distance.

There are many good computers with elevation data out there, but I can't point to a specific one.
That's not quite true. I've been able to get quite accurate estimates for the grade using my power meter, speedometer, and bathroom scale.

-ilan
 

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I believe the phrase "20.9 km climb to 5.6%" is a literal translation from the French. Sometimes the prepositions get messed up (at, on, to, with...). Perhaps a more accurate translation would have been "20.9 km climb at 5.6 %"
 

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bianchi77 said:
Thank you very much for the detail...

So if I climb for 5km with the altitude 700m
The gradient is 700m / 5000m is 14%....?

Anyone know the good altitude and distance computer ? maybe from cateye ?
"Altitude" has nothing to do with it. It is the CHANGE in altitude divided by horizontal distance that gives you the grade. Your calculation would be pretty close if you start at sea level (elevation/altitude = 0) and then ride up to an altitude of 700m over 5,000m.
 

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Mt Washington is 12.1 km @ 12% gradient- tougher

than Alpe-D'huez, except it doesn't require 190 km ride before starting the climb. They also run a century the next day, maybe they will one day run the century and have the 7.6 mile climb for a finish.
 

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Discussion Starter · #18 ·
Kestreljr said:
I have an opinion... Your "Cycling Store" is sketchy as hell; it looks like a scamer's site from 1997, the pics are out of focus (are those even bikes) and none of the links actually work.

Ride on! :thumbsup:
Thanks for your opinion...I will improve it...
And the links are working fine, I have tested them...
 
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