Originally Posted by
kgriffioen
I have read somewhere on these forums that your speed in the cold is reduced by around 10% due to denser air and that your components are not as efficient and that you have on much more clothing. My experience does back this up somewhat.
It's at least 10% for me, and maybe even closer to 20%. That's mainly due to heavier clothing and tires, extra caution while riding in the dark or on icy spots, thicker air, plus less enthusiasm for riding when it's cold. It's slower for sure, but still beats getting stuck in traffic.