There is a period known as civil twilight which is, technically, when the sun is within 6 deg of the horizon before it breaks the dawn. Looking up, dressed in an extra gilet, the cyclist will see the sky is flushed with pinks and reds. With this light, roughly 20 minutes before the dawn, there is enough visibility for a cyclist to click in to begin riding. In the summer at Galibier towers, this is joy for a biker with day long plans. Earthly permission to move.
Cyclists have a close relationship with the sky, and spend our pre-saddle hour looking up at the atmosphere. The calm or angry colours directly controlling our future. Planning our rides by the hue of the clouds and the length of this freedom by the deepness of the clear blue above.
We look at the sky’s colour to assess visibility and potential weather changes, which influences safety gear and clothing choices. An angry grey sky, cloaked Cumulonimbus has us reaching for a rain cape and a planned shorter route. A clear, intense blue sky has us reaching for suncream and the horizon. The current sky colour dictates how visible the cyclist will be to drivers and yet, we don’t measure it. Or we didn’t .
In 1789 Horace-Bénédict de Saussure noticed that as he climbed higher on Mont Blanc, the sky became a darker blue. This led him to conclude that the colour of the sky is influenced by the particles, water droplets, and ice crystals in the atmosphere.
Shortly after, he invented the ‘cyanometer’ – A circle of card, divided into coloured, numbered sections, ranging from white to gradually darker shades of blue. These graduated shades of Prussian, used to measure the intensity of the sky’s blueness and to assist with his studies of atmospheric conditions. It consists of 53 shades of blue, ranging from white to black and it works by holding it up to the sky and matching the sky’s colour to the darkest shade on the chart.
For us cyclists staring up at the blue or grey or white with the cyanometer, we can take a second before putting on our shoes to plan better; and thus enjoy more the ride ahead. When the number correlates with atmospheric conditions like moisture and air clarity, this assists us to pack the correct gilet when the cyanometer reads 14, or a rain cape if the sky shouts a match to 39, when looking out the bike shed window.
Alexander von Humboldt an explorer not a cyclist, was an eager user of the cyanometer on his voyages and explorations. During one trip, he observed at noon on the summit of Teide, a record 41 on the cyanometer scale.
Us modern cyclists, use sophisticated devices to measure our hallowed performance metrics, our watts, elevation gain and aerodynamics. These tools help us track progress, analyse performance, and plan nutritional strategies. Yet they bury us deep in numbers and can pollute the joy of time ridden in the atmospheric blue. The moments spent in the sky, at the top of a climb you have just conquered. It is not truly the 3.7watts/kilo that got you there that will be remembered, but that the sky was a perfect 29, so clear and blue and pollution free. The 29 on the cyanometer was the number of freedom. It entered your soul through the tight chain with a sprocket still to spare.
We have made a Cyanometer sticker for your shed window. When you look out at the sky, take a single second to match a number and your kit choices with that number. The ride will be better, of the correct duration and very much bluer.
