For all my winter riding I will start with a very thin base layer next to skin like a 250 weight wool tank top.
What goes on top of that depends on the temperature.
But keep in mind that you may start to overheat very quickly while fat biking, riding in fresh powder breaking trail requires more effort than just going for a hike in the woods, think about how hot and sweaty you get will shoveling heavy snow, chopping firewood or cross-county skiing .
Just because it is -10*C or colder doesn’t mean that you won’t sweat.
Sweating is VERY bad as you will get cold and possible hypothermia minutes after you stop moving at that high aerobic pace. Eventually you will have to slow down or stop.
If you are cold when you leave your warm house or car to head out for a ride then you may be dressed correctly, remember to bring along a warmer layer/s to have readily available for when you stop to take pictures, have a lunch/snack break or any mechanical emergencies that could happen while out on the trail, it can only take seconds to get really cold.
OK back to the next layer, on top of that I wear a softshell wool jacket, it sheds water and snow but is highly breathable.(Any similar soft shell jacket such as one made of polartec will work, I just really happen to like wool).
Gortex does not work for an upper body layer while doing any highly aerobic activity’s like winter cycling.
What happens is the Gortex “pores” can not keep up with the high humidity/moisture produced by your bodies core and it will clog up and then start to get wet and clammy inside the jacket, next the moisture will turn to ice crystals (sounds cold, doesn’t it?) .
If the weather is getting in the -20* to -40* range or if I am going for more of a casual pace type ride I wear a long sleeve wool shirt between my tanktop and softshell jacket.
While doing longer races I bring along a spare base layer and mid layer to change into if my current one starts to get too sweaty.
When I head out for a winter ride I like to bring a very lightweight/small synthetic “puffy” coat in my frame bag.
But when heading out on a extended race or trip I pack along my expedition/belay down parka to wear once I stop moving and generating that high level of heat.
For really windy cold riding I have been experimenting with a vapour barrier vest, it is great piece for blocking the bitter cold wind from hitting the front of your chest and stomach.
I am a big fan of pogies, I can race in like -5*C in just a tanktop for my upper body if my hands are tucked in some toasty warm pogies.
For riding in 3 or 4*C to about -8* I just wear my summer riding gloves with my regular insulated pogies.
For riding in slightly colder temps I switch to a pair of wool liner gloves, that is all I wear on my hands all the way down to the really cold -40*C and below temps, I just add the fleece liner to my expedition pogies at around -15*C and below.
On occasion I will bring chemical hand warmers with me, I like to use them by just throwing them loose in the pogies, they are also useful for pre warming your cold pogies so you don’t stick your hands in cold pogies.
For longer cold races I pack along a pair of expedition gloves for when I stop and my hands are going to be out of the warm pogies for any length of time.
As you can tell I really don’t like big bulky “winter riding” gloves as they just seem to get in the way, make it extremely hard to eat food while riding and don’t give you the cockpit control and feeling that thin gloves do.
My next post will be on below the waist layering followed by a separate article on footwear.