Devil's Staircase: Cycling Climb

The climb · United Kingdom

About Devil's Staircase

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Simon Warren’s 100 Greatest Cycling Climbs

The approach from Abergwesyn runs through a rocky valley before the Devil's Staircase turns sharply uphill into conifers. The contrast is immediate: a valley road becomes a narrow climbing lane, with the first steep ramp setting the tone. The stored ascent covers just over a kilometre at an average of 12.6%, enough to make its small footprint on the map misleading. This is the climb reached from the east, rather than the descent towards the valley.

The bends divide the effort into distinct passages. A left-hand turn brings a brief easing before the next steep stretch reaches a tight right-hander. Beyond that corner the gradient relents, although the road keeps climbing for a while before the effort is over. Trees and the folded hillside make the ascent feel contained, with little suggestion of its full shape from below. A short road with a clear sequence and a lasting impression.

01 / The ascent

Elevation profile

Start 351 m · Summit 485 m

Gradient by distance1.06 km / 134 m gain

0 km0.2 km0.4 km0.6 km0.8 km1.1 km

02 / The numbers

Climb statistics

Distance: 1.06 km
Elevation gain: 134 m
Average gradient: 12.6%
Climb category: 4
Start elevation: 351 m
Summit elevation: 485 m

Current weather

At the climb start

Loading weather…

Weather data: MET Norway

03 / Your effort

How long would it take?

Enter the power you could hold for the whole climb. We calculate a moving time from the elevation profile and the forces you ride against.

Sustained power

W/kg

Use your intended climbing effort, rather than FTP unless you can hold it for the predicted duration.

Rider weight (kg)

Bike + kit weight (kg)

Bike + kit includes clothing, bottles and luggage.

Advanced settings

Defaults represent a road-bike scenario. Adjust these settings to match your tyres, drivetrain and riding position.

Effective drag area (CdA) (m²)

Rolling resistance (Crr)

Drivetrain efficiency (%)

Modelled moving time

9 min

Power throughout: 225 W
Average speed: 7.3 km/h

Based on the 1.06 km elevation profile. Assumes steady power, with no stops, braking or drafting. Rounded to the nearest minute.

The science behind the calculation

For each part of the stored profile, we solve the steady-state cycling power equation for speed, then add distance ÷ speed across the climb. Gravity uses rider + equipment weight; available power is W/kg × rider weight. This uses the profile’s distance and elevation together, without mixing in another route’s metrics.

Power × efficiency = gravity + rolling resistance + air resistance + bearing losses

The resistance equations are adapted from Martin et al. (1998), Validation of a Mathematical Model for Road Cycling Power. Air density changes with profile altitude using NASA’s standard-atmosphere model. This calculator’s adaptation has not been independently validated.

It predicts travel at the power you enter, including on descents. It does not model acceleration, cornering, braking, traffic, wind, changing weather or fatigue. At altitude, choose power you can sustain there: thinner air reduces drag, but this model does not predict its effect on your ability to produce power. Profile quality and assumed equipment settings also affect the result.

04 / On the ground