hashde said:...one minute into a decent, and I'm shivering so much from the cold I have to stop...
...there's your problem there - stopping. Think like Chef in Apocalypse Now - never get off the boat. 😄
I've ridden as low as -35c. -20c is lovely, assuming you're dressed for it, but -35 is sheer bloody misery no matter what.
Dress for 10 minutes in. If you're warm when you start, you'll sweat up like mad. As mentioned above, sweat on your trunk needs to be managed, and heat in your extremeities needs to be maintained. Miracle materials may help with moisture transfer. Gloves are pointless below -15c, even the lobster mitts. Use mittens. Tying them to a string that passes up your sleeves is optional, as the tough kids will tease you. Use a cheap helmet. Masking tape covers the vents adequately for the purpose, and considering road conditions, you're really going to want a helmet. Plus, masking tape on your helmet and mittens on a string give you "street cred" like you wouldn't believe.
Clipless is not something I'm comfortable with in winter, as there are times I want a foot down RFN (Right F'n Now) and if I'm clipped in, that ain't gonna happen. I wear Chuck taylors with wool socks down to about -10c. below that, or in substantial snow, it's Merril's slip-on snowboot - light, easy, and reasonably warm. Think light and warm in this area - big honkin' Sorels represent about 10 pounds of rotating mass, and will wear you out quick.
I have the widest possible tires on my bike - big snarky downhill things. I think they give me a little flotation, and are less likely to dig in or plow out on corners than skinnier treads. Others in this neighborhood (Edmonton, AB) opt for skinny tires, beleiving the additional pressure give better traction. I'm not convinced, but to each their own.
Derailleurs have a tendency to gunk up and cease operation in my neighborhood, but YMMV. After 4 years of commuting on a ghastly ol' Norco Mountaineer converted to 3 speed (1st and 3rd packed it in early, so she was a single speed for much of her time last winter) I've built up a single speed on a Jamis frame, and look forward to trying it out in the goop we'll be getting here any bloody minute. I'll let you know how it works out.
Good luck with your winter riding, bud. Enjoy the change!
Your pal,
D.A.D.