Purin Hill: Cycling Climb

The climb · United Kingdom

About Purin Hill

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Simon Warren’s Cycling Climbs of Scotland

Purin Hill takes a road built for a practical destination and turns it into a concentrated cycling climb. Leaving the A912 on the eastern side of the Lomond Hills, the ascent heads west towards the masts and parking area below East Lomond. The hilltop walking route continues beyond, but the road climb has a distinct finish of its own. As height builds, the lower countryside gives way to the more open ground around the communications site.

The road gains roughly 223 metres in about 2.3 kilometres, leaving little room for the effort to become casual. Its overall westward line makes the short distance feel purposeful, with the higher ground always drawing the ride away from the main road below. Around the finish, the outlook opens towards the Forth and the fields of Fife. It is a compact ascent whose utility-road character suits the sustained climbing.

01 / The ascent

Elevation profile

Start 110 m · Summit 333 m

Gradient by distance2.26 km / 223 m gain

0 km0.5 km0.9 km1.4 km1.8 km2.3 km

02 / The crux

Where it gets difficult

Choose a distance to find the steepest continuous section of the climb.

Steepest 500 m average

11.7%

Where to find it

0.20–0.70 km from start

Net height gained: 59 m
Section length: 500 m

The whole climb2.26 km

0 kmFinish

03 / The numbers

Climb statistics

Distance: 2.26 km
Elevation gain: 223 m
Average gradient: 9.9%
Climb category: 3
Start elevation: 110 m
Summit elevation: 333 m

Current weather

At the climb start

Loading weather…

Weather data: MET Norway

04 / 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

15 min

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

Based on the 2.26 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.

05 / On the ground