Devil's Elbow: Cycling Climb

The climb · United Kingdom

About Devil's Elbow

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Simon Warren’s Another 100 Greatest Cycling Climbs

South from Heol Senni, the road towards Ystradfellte climbs onto open ground and bends back on itself at the Devil's Elbow. The approach loses its enclosing hedges as the hillside takes over, making the turns ahead part of the view. In less than two kilometres the ascent gains about 180 metres. A relatively direct opening leads towards the bends, but the gradient builds as you approach the section that gives the climb its name.

The first hairpin turns left into the hardest part of the road, with the connecting slope demanding more than the opening. A second turn brings another change of direction without immediately ending the effort. Only beyond these bends does the climbing become noticeably kinder on the way towards the crest. The shape is easy to remember: an open approach, concentrated work around the turns, then a gradual release. It is a short ascent with a distinct and satisfying sequence.

01 / The ascent

Elevation profile

Start 267 m · Summit 452 m

Gradient by distance1.88 km / 184 m gain

0 km0.4 km0.8 km1.1 km1.5 km1.9 km

02 / The numbers

Climb statistics

Distance: 1.88 km
Elevation gain: 184 m
Average gradient: 9.8%
Climb category: 3
Start elevation: 267 m
Summit elevation: 452 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

12 min

Power throughout: 225 W
Average speed: 9.2 km/h

Based on the 1.88 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