Friday 10th 28F, -2C, heavy overcast, breezy from the east. Supposedly remaining dry today. Wind speeds are expected to gust to 10-12m/s. [20-25mph] Which means that standing still at such freezing temperatures the wind chill factor is around -15C or more. It's no wonder it feels colder as you descend or ride faster.
Yesterday I reached nearly 30mph downhill. 15m/s @ -2C = -20C. Warm clothing isn't so vital as excellent wind proofing. On descents and during gusts I could feel the cold pressing against my clothing as it neared its limits on blocking the wind. No doubt my multi-layer clothing was also being flattened by the wind pressure as my speed increased. My upper arms and upper chest feel it most on descents or into headwinds but it is not nearly enough to worry about.
Very few cyclist are out and about at these temperatures. I saw one hardy mountain biker yesterday. We grinned at each other through our body armour of clothing. I have foolishly ridden at temperatures down to -15C before I found suitable clothing. The pain in my hands and feet was excruciating! The multiple fleece jackets absolutely worthless at blocking the wind and far too warm to boot. I was wearing trainers back then with toe clips and traps.
Then, I was incredibly fortunate to find a series of proper winter cycling jackets at charity shops at about a fiver each. Not those paper thin things people wear today but still with "technical" cloth to block wind without being waterproof. I find it interesting that I never see anybody out training at freezing temperatures in the expensive and thin, winter cycling wear. It obviously doesn't give enough comfort or there would be more people wearing it.
That prickle in your back is a warning of overheating and must be attended to immediately. Even if it means stopping to take off a scull cap or opening your jacket wide. Sweat is your arch enemy and waterproof clothing will never let it escape.
Cycling in a PU coated nylon anorak or cagoule is a recipe for disaster! You set off feeling all safe comfortable and warm but just go on getting warmer and warmer. Before long you can feel the sweat running down your sides, chest and back. Your expensive, waterproof jacket is worse than a black bin bag! At least a cheapo, bin bag can let some sweat out at the arms and neck hole. The PU anorak or cagoule are sealed at every orifice [and seam] except at your panting mouth.
I rode 15 miles back and 15 miles forth every day in my youth to get to work. I was absolutely freezing in winter so I stuffed a newspaper inside my jumper. That helped but it wasn't very comfortable for a daily ride. So I "invested" in a Black's PU coated jacket. It was lovely for the first mile and then rapidly became a mobile sauna. I carried no spare clothing. So had to sit and stand around sopping wet [in my own sweat] until lunchtime before I finally dried out in the warm office.
I used the same jacket to go winter mountain walking and rock climbing in Snowdonia. It was always horribly wet and/or cold in the mountains. That PU jacket made my life an absolute misery! I "enjoyed" a constant sweat bath on every single climb and then froze at the summit or on exposed ridges. There was no way to remove the jacket once I was wet through without risking severe hypothermia!
A good, old fashioned, tightly woven, cotton anorak would have breathed even if it was damp on the outside. Regular re-proofing would help to keep it drier. Or even a really good tweed jacket would do at a pinch. It's just a shame they don't allow easy, buttoned closure right up to the neck. The vast majority of tweed wearers aren't remotely outdoorsy people and just want to show off a shirt and tie. The tweed jacket was once the material of choice for the outdoor laborer. The greasy wool shed some of the constant rain. A breathable hessian sack would become a cape when it absolutely poured down.
There was a recent test of 1930s technology mountain clothing in the Himalayas and it proved successful. Tents were made of breathable but windproof fabric for millennia before the sweaty PU, flappy nylon things came along. Though admittedly the plastic tents were much lighter if you needed to physically carry them with you. I mistakenly tried a lightweight, single skin, PU nylon bivouac tent on one trip to Snowdonia. I never slept for a week due to the constant rattling of the thin, hard, nylon fabric. Then there was the constant rain from my own sweat and condensed breath being shaken off the inside of the same fabric onto my sleeping bag. Never, ever again!
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