
Red Box
Red Box is a 24.4 km Category 1 US climb whose modest 4.69% average hides steep ramps and over 1,500 m of extra ascent from undulation.
- Length
- 24.4km
- Avg
- 4.7%
- Max
- 25.0%
- Summit
- 1,453m
- Ascent
- 2,658m
The climb
Gradient profile
Overview
Red Box is a Category 1 climb in the United States, running 24.4 km from a start elevation of 306 m to a summit at 1,453 m. On paper the headline number is straightforward: a net elevation gain of 1,147 m spread across nearly 25 km, averaging 4.69%. That profile reads like a long, steady tempo effort, and for stretches it is.
The reality is more demanding. While the net gain is 1,147 m, the total ascent is 2,658 m — roughly 1,511 m of climbing that does not show up in the point-to-point elevation difference. That gap is undulation: the road repeatedly gives back altitude and then reclaims it. You will descend and re-climb enough to more than double the "official" vertical, which means your legs do far more work than the average gradient suggests.
How the Gradient Unfolds
An average of 4.69% is a poor guide to Red Box. Undulation flattens the mean, so the number sits between long false-flats and genuinely steep pitches. The steepest recorded ramp hits 24.96%, a wall that will force you well below tempo pace if you meet it with the wrong gear.
Expect the profile to break down roughly like this:
- Flatter and recovery sections where the road drops or eases, letting you spin and eat
- Repeated short climbs that stack up into the 1,511 m of extra ascent beyond the net gain
- A steepest ramp near 24.96% that demands your lowest gear and a controlled effort
Pacing Notes
Because Red Box undulates so heavily, even-speed pacing is a trap — holding a constant pace over the steep ramps would spike your effort and cost you on the back half. Pace by effort instead, anchoring to your sustainable power output rather than the clock. On the flatter and descending sections, deliberately back off; on the steep pitches, let your speed fall while keeping wattage in check.
If you do not know your numbers, run the FTP estimator before you go and set a ceiling you can hold for the full 24.4 km. Given the total ascent of 2,658 m, treat every recovery section as a chance to sit under threshold, not as free speed.
Gearing
The 24.96% ramp governs your setup. On a gradient that steep, a standard chainset will have you grinding at unsustainable torque. Fit a compact (34-tooth inner) or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you the low end to keep cadence up the walls without blowing your legs. Check your drivetrain before the ride; there is no fixing your gearing on the mountain.
Summary
- Length: 24.4 km
- Average gradient: 4.69%
- Maximum gradient: 24.96%
- Net elevation gain: 1,147 m
- Total ascent: 2,658 m
- Category: 1
Red Box is a Category 1 climb that rewards riders who pace by effort and gear for the steepest pitch. Respect the 1,511 m of ascent hidden in the undulation, and the 24.4 km will unfold under control.