How do the climb directions work?
Many of the climbs are listed with a direction -N (North), -S (South), -E (East), -W (West). The direction is the side of the pass\climb that you ascended. For example, Grand Mesa -N is a climb starting north of the summit and riding south. There are 2 passes marked E&W. These passes are rated by climbing over the top starting in the East and then back over again from the West in the same ride. Finally, some passes have no direction indicator. They are one directional climbs such as Lefthand Canyon and Mt. Evans.

How are the climbs picked?
The table of climbs includes all of the paved passes in Colorado along with "classic" or "show case" climbs in the state. We have listed many of the climbs from two directions since the rating can be very different. We also combined the double pass climbs into one entry. So for example La Manga and Cumbres are listed as one climb.

If you have a climb that should be on our list drop us an note.

What is the method used for rating each climb?
One of the challenges in compiling the database was to find an objective way to compare climbs. While we started with Cycling Colorado's Mountain Passes by Kurt Magsamen, it quickly became apparent that his ratings were subjective. More importantly, there was no clear method to use when adding new climbs to our database.
The solution to this problem came from the KOMCycling website. In an article written by Luddo Oh, he describes four different methods for rating climbs. The one we ultimately selected, originally from the Dutch bicycle magazine FIETS, combines Grade with Altitude Gain. The formula is the vertical rise multipled by the average grade and reduces to:

[ H2 / 10D ]
where H = height difference in meters,
and D = distance traveled in meters).

A 6.2 mile climb with a height difference of 3,281 feet (10% grade) will be rated at 10. This is the same rating as a 12 mile climb with a height difference of 4560 feet (7% grade).

So what is the "hardest" climb in the Colorado database?
Mt. Evans earns that distinction with a rating of 9.0. Three of our climbs rate greater than a 6. For European references: L'alpe d'Huez scores a 10.0 (and it is only about 1/3 as long as Mt. Evans), and Mont Ventoux rates 12.7! The highest rated climb listed at KOMCycling.com is the 2,865 meter climb up Pic Du Midi Di Bigorre in the French Pyrenees with a rating of 19.7. We don't know about you, but a climb that is twice as hard as Mt. Evans gets our attention.