The Mike Horgan Hill Climb is this weekend, so I am putting up the profile of Sugarloaf Road. The Horgan has alternating / varying courses, so this profile is from the bottom of Sugarloaf Road to the summit of the climb next to Sugarloaf Mountain at the intersection of Switzerland Trail Road.
Length: 4.68 miles (7.53km)
Average Grade: 8.0%
Maximum Grade: 11.3%
Vertical Gain: 1977 ft (603m)
Summit: 8088 ft (2465m)
Tour de France Category: 1
Tour de France analogue:
Col de Marie-Blanque – Second Climb, Stage 17, 2010 TdF
Sugarloaf Mountain is a prominent feature and can be seen from many places in Boulder and the Front Range. It is a bald, pointy mountain shaped supposedly like a lump of sugar. I have always enjoyed being able to see my destination from the start of my ride.
The ride begins ascending Boulder Canyon. This road is narrow and has heavy traffic and minimal shoulder. Many cars are polite, but remember to pick low traffic times and stay as far to the right as possible. I try to minimize my time on in Boulder Canyon, as there are many safer alternatives in town.
However, after ascending just over four miles of Boulder Canyon at an average grade of 2.4%, you have reached a climber’s paradise. Magnolia Road ascends the south side of Boulder Canyon, and Sugarloaf ascends the right. After the turnoff the climbing begins in earnest with an average grade of 8.3% for the first half mile.
You only get a short break with a brief downhill passing the turnoff to Betasso, which has a fast, short mountain bike loop. Then the road ascends the ‘canyon’ portion of the climb and is steep again (average gradient 8.0%) and is very twisty. After you pass the firehouse the canyon opens up, and the grade increases again and will remain above 10% for the last two miles.
The climb comes in waves with steep, straight sections each a couple hundred yards long separated by curves and very short, flatter sections. Once you have Sugarloaf in view, only a mile remains, but the gradient is now over 11%. After cresting the summit, the road becomes rideable dirt with flat to rolling hills and continues six miles to Peak to Peak Highway.
If you continue to Peak to Peak, you can descend Boulder Canyon, which is somewhat safer downhill since the upper canyon is steeper and you can keep up with traffic. However, it is a much nicer ride to head northward and descend through Ward.