Road Bike Racing - How are hills/climbs rated?

I'm a cycling novice and learning through forums such as this. I read about "hills" and "climbs" with vague references to degree of difficulty. Are there general rules of thumb that describe, somewhat objectively, hill/climb difficulty? For instance, I would think that given our metric-intensive sport that hills would be at least categorized by length and angle of ascent (steepness). How difficult would, for example, a one mile (four degree) hill be?
Paul (San Diego)

Originally posted by flash619
I'm a cycling novice and learning through forums such as this. I read about "hills" and "climbs" with vague references to degree of difficulty. Are there general rules of thumb that describe, somewhat objectively, hill/climb difficulty? For instance, I would think that given our metric-intensive sport that hills would be at least categorized by length and angle of ascent (steepness). How difficult would, for example, a one mile (four degree) hill be?
Paul (San Diego)

mostly all of the notable climbs in the tour are catagorized...they range from...

cat 4
cat 3
cat 2
cat 1
hor catagory (off the scale)

all are weighted by their length, grade, and road surface i think.

but, they may be two types of climbs, both VERY different in form that get the same rating. lets say you have a shorter, steep, cobble stone climb in belgium that is like 1/2 mile long and has pitches from 12-18%. that may get a catagory 4. but another climb in france may be 2 miles long, average grade at 7%, and that will also get a cat 4 rating. (i'm not sure where in altitude these would end up, just using it as an example)

climbs like Alp de'huez and Mont Ventoux are Hors catagory which means they are more difficult than a catagory 1, so thats the name they are given...

As stated above plus also where they are placed on the race.

You can have a normal Cat 3 on a race and then on another event it may be the finish and then it would upgrade to a Cat 2

What I've found for TdF (and NOT other races)

The organizers of the Tour de France also claim that the quality of
the road surface can influence the rating of a climb. If the surface
is very poor, like some of the more obscure climbs in the Pyrenees,
then the rating may be bumped up.

4th Category - the lowest category, climbs of 200-500 feet(70-150m).
3rd Category - climbs of 500-1600 feet(150-500m).
2nd Category - climbs of 1600-2700 ft.(500-800m)
1st Category - climbs of 2700-5000ft(800-1500m)
Hors Category - the hardest, climbs of 5000ft+(1500m+)

Points awarded for the climbs ranges are as follows (from the 1990 race bible):
4th Category: 3 places: 5, 3, 1
3rd Category: 5 places: 10, 7, 5, 3, 1
2nd Category: 10 places: 20, 15, 12, 10, 8, 6, 4, 2, 1
1st Category: 12 places: 30, 26, 22, 18, 16, 14, 12, 10, 8, 6, 4, 2, 1
Hors Category: 15 places: 40, 35, 30, 26, 22, 18, 16, 14, 12, 10, 8, 6, 4, 2, 1

Steepness also plays a factor in the rating. Most of the big climbs
in the Alps average 7-8% where the big climbs in the Pyrenees average
8-9%.

Marty
THe above is from http://draco.acs.uci.edu/rbfaq/FAQ/5.3.html

Here's a similar thread from a month ago. (http://www.bikeforums.net/showthread.php?s=&threadid=9214)

Thanks all for the info. Now I know that my local killer hill is only a Cat 4 :rolleyes: bump.

My only other question is about the "% grade" metric. Is that the same as "degree angle"?

So, very hypothetically and trigonometrically-speaking, a 1.414 mile ride that climbs 1 mile vertically would be a 45 degree
climb. (A squared plus B squared equals C squared). Is that the same as % grade?

The reason I ask is that I read about 18% grade climbs and have trouble believing there are hills that steep.

No, the % and the degree angle are not the same. Unless my trigonometry is really rusty (which it could be), the sin of the degree angle will equal the percent (sin of angle = opposite over hypotenuse, the "soh" in "sohcahtoa") To get the degree angle from the % you take the inverse sin of the rise/distance covered.

So, 18% means you go up 18m while going 100 meters on the road. The inverse sin of .18 is 10.4 degrees.

Yes, they do exist, but not much. They are more common in Europe than in the U.S.

Cheers,
Jamie