Winter Cycling Boots for Fatbiking and Tips for Keeping Your Feet Warm

Stay warm, ride happy.  Part II.

by | Oct 2, 2020 | Gear

This is Part II of the Stay Warm, Ride Happy series.  Also see Winter Pants for Fat Biking.

The biggest challenge with winter cycling on my fat bike is finding the right winter cycling boots to keep my feet warm.  I’ve been riding a fat bike in the snow since 2012 and I’ve noticed that, on the whole, my feet get colder than my partner’s. 

It’s not just in my head.  Women’s feet really do get colder than men’s. One of the reasons is that vasoconstriction happens more quickly in women. The blood flow to skin shuts down sooner and more intensely than in men, and afterwards it takes women longer to warm up¹. Women also have a lower metabolism – the process of burning food for fuel which heats up our bodies.  It’s another reason we are slow(er) to generate heat.

I mostly have a system dialed in to keep my feet warm but I wanted to know what the pros do! To that end, I asked six women who are ultra-endurance winter athletes what boots they wear and their tips and tricks for keeping their feet warm.   

The boots listed here aren’t gender-specific but I wanted this piece to be by women for women.  The recommendations are for those who ride either clipless or flat pedals and and applies to day-trippers as well as aspiring endurance athletes.

“If you are a flats person, don’t forget to check your closet for good winter boots. My first pair of winter fat boots were my mountaineering boots. Look for a stiff-soled boot with good flexibility in the ankle.” – Nan Pugh


Winter boots for cycling and fat biking

A mishmash of winter boots on a Christmas Day fatbike ride with friends.




Nan Pugh

Winner of the 200k Fat Pursuit in 2018 and placed third at Tuscobia 80 in 2019. I have attempted the Fat Pursuit 200 mile and Drift 100.


I grew up in Louisiana, I was 18 when I had my first snow experience. Don’t worry, I have been making up for lost time.

I have learned that I hate being cold. I have picked up a few tricks that help to keep me comfortable in winter.  Many of the tricks I learned or were greatly reinforced when I went to Fat Camp hosted by Jay and Tracey Petervary. If you have the chance to go it is well worth the time and money.

Winter boots and keeping your feet warm.

First, this is from my experience, I am super lucky that I don’t Raynaud’s Syndrome (poor circulation in your hands and feet). What works for me may not work for you. Play around with things, particularly before the super cold or the big event.

Second, clipping in or flats?
Flats – If you are a flats person, don’t forget to check your closet for good winter boots. My first pair of winter fat boots were my mountaineering boots. Look for a stiff-soled boot with good flexibility in the ankle.

Clipless – There are a few different options, 45nrth, Bontrager-Old Man Winter Boots ($274 – Trek Bikes), and Lake MXZ 400 Winter Cycling Boot ($439 – Competitive Cyclist) are the main companies that I know of. I have 45nrth and haven’t tried Bontrager or Lake boots. 45nrth makes two different winter boots: Wolfhammer and Wolfgar. Both boots are stiff sole but walk very well.

Wolvhammer winter cycling boot

Wolvhammer winter cycling boot

1. 45nrth Wolfhammer ($475 – REI) is a standard winter boot 25-0 degrees, last year they updated them with a removable liner. I haven’t tried the new ones on. I have worn mine at -20 and with footwarmers was fine. I would recommend these boots for above 0 degrees and rides that are less than 6 hours.

Wolfgar winter cycling boot

Wolfgar winter cycling boot

2. 45nrth Wolfgar ($475 – REI) is a cold winter double boot, warm to -25. The downside of these any of these boots they are unisex, which for me with a narrow foot is a major bummer. When I bought my Wolfgars a few years ago the smallest size they made was 40 (now it is 38), which was huge on my foot.


Intuition liner and Wolfgar boot.


By chance, I owned a pair of Intuition Liners for plastic mountaineering boots and they fit in my Wolfgars! I brought my boots and Liner to the local ski shop to have them molded and it has worked amazing for me. I will say it is a pricey setup but for me well worth it. I have never had cold feet or blisters (which I had with Wolfhammer).

Intuition liner and original wool liner

I would recommend these boots if you are going to ride below 0 or have major circulation issues or riding for long distances. I wear my Wolfgars 80% of my riding, they are comfy at 15 above. I have camped with them, my sleeping bag is too narrow to allow boots in them. So they have to stay out, I have put my cold foot in them and they warmed up quickly.

Guidelines and tips and tricks:

  • No tight boots! It is worth it to size up for winter boots, extra room for thick socks, additional insoles. You want good circulation, tight boots = poor circulation.
  • Vapor barriers, these are plastic bags (Chicken baking bags work well) that keep your foot warm. My feet sweat a ton so I haven’t used them as much. I know a number of folks who swear by them. (large size not turkey)
  • Gaiters! This is two-fold, it will prevent snow from getting into your boot, and second, it will help keep your lower leg warmer.
  • Foot and hand warmers, work well in front of your ankle, not in your boot. The handwarmer needs air to be activated in your boot will likely be too tight for them to work well. This placement is also near where blood enters your foot so the warmth will be more effective.
  • Long rides, more than 6-8 hours I will stop and wipe down my feet with baby wipes to prevent salt rash.
  • Listen to your body! If your feet are cold for a long time even without being frozen this can damage your nerves over time. If you notice your feet are cold at 15 degrees then making sure that you change your system so it warmer then next time you go out is important. Cold feet should not be something you try to push through. If you get a freezing injury you are at a higher risk for frostbite in the future.



Leah Gruhn

8-time finisher Arrowhead 135, 1st time finisher Iditarod Trail Invitational, 6-time finisher Tuscobia


Why are warm feet so important? This is not simply a matter of comfort, although that’s a nice side benefit. It’s all about preventing feet and toes from frostbite, which in severe cases, can prevent you from ever enjoying cold weather again. 

Friends of mine have damaged their feet in winter bike races to the point where they can no longer do winter outdoor activities lasting longer than 30 minutes, including bike races. Not cool! 

When it comes to keeping feet warm, you can not take a set-it-and-forget-it approach, or a tough HTFU (harden the “freak” up) approach for that matter. You can’t simply buy the best boots / gear and rely on those to keep your feet safe no matter the conditions. You are responsible for doing what it takes to make sure that your feet stay warm. 

Trial and error is needed to figure out what works the best for you in certain conditions, so use every outing as an opportunity to dial in what is best for a given temperature. 

Here’s my current setup in the coldest of conditions:

I first put on a cheap thin polypropylene tube sock, followed by a large Reynold’s oven bag (I used to use Subway bags, which work as well and are free). The sock keeps the bag off your skin and the bag prevents evaporative cooling. 

I follow the bag with a thick wool sock, like Darn Tuff or Smartwool. 

On top of that, I wear 45nrth Wolfgar boots, which are the warmest cycling boots on the market, and allow me to clip into my pedals (which help with bike handling in squirrely or challenging conditions). 


Forty Below Overboot

Forty below Light Energy Overboot ($149)


On top of my boots is a Forty Below neoprene overboot into which I’ve cut out a hole for my cleat. (Note: these would not work for flats because the pins would tear up the bottom of the overboots.) If the ride / race will be super cold and a relatively short duration (less than 24 hours), I may bring some toe warmer chemical heat packs and put those on top of my toes. 

I used to wear a pair of Keen Summit County winter hiking boots before I upgraded to Wolfgars.  (Fatbikegirl note: I also wear the Keen Summit County winter boot because I ride in flats.  It looks like the Keen Men’s Revel IV High Polar Boot replaced the Summit County boot.)

With all of that, my feel may likely still get cold after hours outside in sustained extreme cold. One option is to get off and walk your bike until they warm up; this can take a while. 

Another option is to get off your bike and swing your legs back and forth as high as they go. How many foot swings should you do? Enough that you warm up! Maybe it will just take 25 swings for each foot, maybe it will be 100. Keep monitoring your feet and addressing any coldness until you are indoors.

As an aside, you may be wondering why feet get so cold in the first place. For those of you that took physics, remember angular velocity and think about how much further feet travel through space at, say 60 rpm, than any of the rest of your body. Your feet are moving faster, which cools them faster. That combined with having relatively low volume to surface area and being at the end of appendages makes them particularly difficult to keep warm. 

Good luck and stay safe!


Jill Martindale

First woman to finish the 200 mile Fat Pursuit and hold the Arrowhead 135 course record and ride for Salsa and 45nrth, 2020 Winner Iditarod Trail Invitational


I’m going to preface this first by saying I’ve been incredibly fortunate and that I have never experienced frostbite on my toes! You might say it’s luck, you might say I’ve had some really great teachers help me along the way, or you might say I have some things figured out – I think it’s a combination of everything! 

I try to take time after every winter ultra to list out what worked well and what didn’t work, how I packed my things, and what I would change for next time. It’s been incredibly helpful in figuring out what works best for me and I’ve picked up some awesome tricks along the way. I’ve dialed in my boot system and have figured out what works best for me.

Everyone is different, so try to be aware of how your body reacts to different things! I learned that I become dehydrated when I am on my period, and I know that dehydration can cause frostbite, so I drink more water to compensate for that. 

I learned that I get chilled easier the more fatigued I get, so when I know I’m headed out in to the night and I’ve been riding all day, I prepare ahead of time by using toe warmers on top of my toes before the temperatures dip. (Any given night lasts about 8 hours, right? They make toe warmers that last that long – so if you pop them in at sundown you know you can make it most of the way through the dark – as soon as the sun comes up it’ll warm up again). 

During the Iditarod Trail Invitational (ITI) I had 3 steps I needed to take at each checkpoint and I wouldn’t allow myself to get caught up in the race mentality and rush out of there. These were steps that I learned kept me happy for longer and when thinking of the times that I felt good out in the cold. Those steps were: 

  1. I needed to leave with dry socks and gloves 
  2. I needed to eat what they offered me 
  3. I couldn’t leave until I went to the bathroom. Keeping myself in check at these spots helped to keep me going out in temperatures ranging anywhere from -65 degrees all the way up to 40 degrees. By taking the time to take care of myself I prevented mistakes down the line. I think a lot of people forget that frostbite can happen when you’re dehydrated, and it’s so easy to get dehydrated in the cold! 

My boots of choice are the 45Nrth Wolfgar boots. They have a wool liner on the inside and I love wool in the winter! They also use aerogel and a water-resistant membrane to help keep moisture out. I placed a construction-level trash bag between the boot shell and the liner to reinforce the water-resistance of the boot. Although they’re advertised as being waterproof, I didn’t want to take any chances! 

Wearing something every day for 20+ days causes it to wear down way faster than wearing it occasionally over a few winters and I wanted to take all the precautions I could so I didn’t find myself in any messes out there. On the very cold days when I knew I’d be sleeping outside, I used wool socks on my feet and then used a vapor barrier to keep the sweat close to my foot so that it wouldn’t leak out on to the wool liner. 

When the temps were above 0 degrees I did not use the vapor barrier liner. Each time I went in to a checkpoint or when we were able to sleep inside, I would remove the liner from my boot to let it air out and dry. When I slept on the side of the trail, I left my boots on to sleep in – or you can take the liners out of the shell and sleep with those on your feet like slippers. I know it sounds weird, but I promise you’ll be so tired you won’t even notice you’re wearing them!! 

I was with Leah Gruhn once at Fat Pursuit and had taken my boots off to sleep – in the morning they were frozen and I could not get my foot inside of them! It was the worst!!! By leaving them on I keep my tootsies warm and I eliminate the possibility that the boot will freeze and that it won’t budge. By keeping the liners next to my body, or by leaving the boots on, I don’t have to swear and hop around and try to cram my foot in to an impossibly tight spot. 

To help protect my sleeping bag from the studs that I have on the bottom of my Wolfgars, I slip my feet in to a sleeping bag vapor barrier. This protects the inside of my sleeping bag from getting wet and making me chilled. It also keeps the material safe from the sharp studs and it keeps it clean: bonus! 

If my feet are still cold after all of these precautions, I’ll get off my bike and walk to help generate some heat in my feet. Sometimes it’s nice to have a little bit of a break from pedaling, anyway!

I do spend time running and hiking with my dogs in the Wolfgar boots at home to get used to being in them and to make sure they’re worn in for my foot. Getting blisters in the winter stinks! 

There was so much pushing in the first few days of ITI this year that I got blisters from all of the walking despite feeling comfortable on long hikes in my boots. I should have done some mega long dog walks. The good news is that they’re hella worn in to my foot now! 

I typically wear a size 39 in mountain bike shoes and sized up to a size 40 Wolfgar to allow for extra toe wiggle room. Air is a great insulator, so its important to leave some space in your winter boots so you’re not cutting off circulation. (I wear baggy clothes all winter to help keep my entire body warm.) Staying hydrated, staying fed, staying rested, and staying dry will keep you nice and warm!!

***Jill started a winter bike-packing camp last year called the Winter Shakedown in Michigan for folks who want to dial in their winter camping set up and prepare for winter ultras. They are still working out a location this year due to covid, but plan on hosting it again!***


Betsy Williford

Aspiring Winter Ultra Athlete (Fat Pursuit 200k attempt) with multiple mid-distance winter race finishes and placements under my belt

@motrnmini (IG),


My system for my feet for winter riding / racing and keeping my feet warm / dry is as follows….  45Nrth Wolfgars – maybe sized 1/2 size up – I am not certain I really sized mine up because I am between sizes anyway.  Alpaca wool insoles in addition to the standard wool liners that come with the boots. 

I put on a thin wool sock then oven turkey bags as my vapor barrier followed by a thicker wool sock. Thickness of socks depends on the temps I am expecting.  I always choose wool or synthetic socks. No cotton! 

All of this is finished off with 45nrth gaiters. 

If it is really cold, near or below zero, I put toe warmers on top of my toes on top of the thin sock. Then I cover with vapor barrier and second wool sock. I had bad cold exposure to my toes last winter so they are more sensitive to the cold anymore. So most of the time I will use the chemical warmers if I know I’m going to be out for hours and hours.

Note – I don’t put the chemical warmers under my feet because they are uncomfortable when they are done and harden up. Like walking on rocks. So I learned to put them on the top side of your toes.

One other trick I learned is to once a year seal the seams on my boots and also put snoseal on them to help minimize any moisture leaking in. 45NRTH boots are not waterproof.

My pedals have a flat side and a clipless side. I personally like it … I can clip in when I feel confident and conditions are fast or I can use my flats when it’s a slog fest and I can’t balance very well.


Betsy’s winter boot set up.



Jamye Chrisman

Women’s 200k Winner of the 2020 Fat Pursuit fat bike race3rd place finish in the Winter Bear in Steamboat

First off I’d like to clarify I am a flat pedal user in winter so I have chosen to buy boots that don’t have cleats.  The first boot I had success on day rides (including the 60k Fat Pursuit) in temps down to zero degrees was a boot by Keen with 400 gram insulation.  I’ve used it for a few winters now however I realized during Jay P’s Fat Pursuit Camp last winter where temps dropped to -10 F one night that these boots had reached their level of comfort for me. My feet got a bit chilly but nothing like frost nip or frost bite but just chilly.

That Keen boot still works great for day rides in winter temps down into the single digits for me. I knew that if I was going to be out in cold temps for a longer period of time or for multiple days that I needed to get a warmer boot and something maybe sized up to allow for multiple socks and or a vapor barrier sock.  

I chose to go with the Salomon Toundra Pro.  It’s rated to -40F but that’s just a rating and until my feet are in that temp for a somewhat extended period of time I’ll just use that as a reference until proven.  I chose to size up one full size and this has allowed me to wear a sock system that consists of a thinner liner sock with a vapor barrier sock ( I went with the inexpensive but tried and true by many others oven chicken bags for a vapor barrier) and a heavier outer sock. 

Solomon Toundra Pro

During the 200K Fat Pursuit last winter this combo worked very well and my feet stayed warm and the outer sock and boot liner did not get wet from perspiration.  This Salomon boot does not have a removable liner. 

When the temps are a bit warmer and I’m not going to be out for more than just a day I can add another foot bed to take up volume and just go with a one sock system which makes the boot more versatile for a range of temps for me. Both of these boots I have written about are comfortable for me to ride in and also work great for many hours of hike-a-biking. Thanks for reading and happy riding!


Jill Homer

Multi-sport ultra-endurance athlete with a multitude of winter races under her belt including the Iditarod Trail Invitational.  She is the author of “Into the North Wind” – 1,000 miles on a fat bike across Alaksa as well as two other books.


Jill’s boot of choice is the Vasque Arrowhead, which are insulated boots designed for hiking and running in subfreezing temperatures. Information here is reprinted with permission from her website Half Past Done:

The Arrowheads’ features include 200 grams of Thinsulate insulation, reflective lining, and waterproof leather for the outer layer. They’re a fair amount lighter and more flexible than boots designed for winter cycling, and for this reason I’m banking on them being the right solution for pedaling and pushing a bike long distances in difficult winter conditions.

Vasque Arrowhead

Vasque Arrowhead

My own rigid boots, designed for winter mountaineering, had served me well for years. But issues always arose when I was out for long days or a wider range of temperatures. The boots were well-insulated, but even the world’s most impenetrable insulation can only do so much when wrapped around a small body part that generates relatively little heat.

Keeping body temperatures well-regulated can be tricky, and once core temperatures drop, feet are the first to lose their heat source. I’ve found when this happens, it can take long minutes, sometimes hours, to bring my feet back to life.

Even getting out of the saddle and running doesn’t always help, because my feet are so encased in a rigid shell that the muscles are limited in their independent motion. “I need something more flexible,” I thought. “Something that will help me maintain circulation through movement, rather than create this cast-like barrier that keeps my feet cold no matter what.”

Of course, cyclists turning pedals don’t use their foot muscles nearly as much as a runner or hiker, so more insulation is needed to preserve heat. To go along with the Arrowheads, my boyfriend, Beat, designed shin-high overboots with primaloft insulation. These lightweight, gaiter-like layers slip over my boots and act as a vapor and wind barrier without limiting motion. 

I also use vapor barrier socks to keep moisture from building up inside the boot or overboots. While spinning pedals I often wiggle my toes or flex my feet to promote continued heat production inside the boot, just in case my core decides to start being stingy.

I tried my new system in temperatures in Fairbanks, Alaska that ranged from 30 above zero to 35 below zero. This system proved to be satisfyingly comfortable in this wide range of conditions for rides that ranged from three to seven hours. 

I even crossed through a section of ankle-deep water and the boots stayed dry. Longer durations in warmer temperatures or long periods of pushing may require removal of the overboots or vapor barrier socks to help move moisture away from the skin. But beyond minimal sweat issues, I was impressed by the versatility of this system. 

My feet started warm and stayed warm, rather than slowly leaking heat as often happened with my other, expensive mountaineering boots. Comfortable shoes that allow the toes and arch to move freely can go a long way toward the goal of happy feet.

Beat’s homemade overboots are my new favorite piece of gear, but similar options are available commercially from Forty Below and other companies that specialize in mountaineering gear. 

If you’re not as interested in spending 300-plus dollars on your winter cycling shoes, it’s also worth considering combining cheaper overboots with a winter trail-running shoe or hiking boot. Maybe less really is more.



Kathy Browning (Fatbike Girl)

Weekend warrior and two-time finisher of the Togwotee Winter Classic 25m, rode some and fell a lot at the West Yellowstone Equinox 24hr Event x 2 


I ride flats in my Keen Summit County winter boots.  The stiffness of these boots is great for riding. The other reason Keens work well for me is that they have a roomy toe box.  Air circulation helps keep your feet warm.  Note that the Summit County boot has been replaced by the Keen Men’s Revel IV High Polar Boot.

When it’s in the single digits to below zero I wear a pair of Ranger Thermolite boots I bought at the local feed store for $49.00.  They are an ugly camo pink but are super warm pak boots.  However, I should mention that the sole isn’t as stiff as I’d like.  This year I am going to try xc ski overboots for my Keens to extend their temperature range.

Wyoming fashion-forward Ranger boots.

My boots are oversized so that I can duct-tape chemical hand warmers over my light-weight wool socks and on top of my toes. I add another wool sock over the sock with the toe warmers.  In addition to warmth, the extra sock helps the toe warmers stay put.

I buy the chemical warmers by the box and use the ones made for hands because the ones for feet don’t cover enough surface area. With the hand warmers you can even mold them around your toes.  The downside is that I always have duct tape stuck to my socks.

I carry extra hand warmers on my bike although they typically last 6-8 hours.  I buy a new box each season because they have a shelf life. The reason I use chemical warmers is because I have Raynauld’s Syndrome and need active heat to stay warm, even when it’s not very cold.

Also make sure that your toes aren’t squished with the hotties. Squished toes = cold toes. Leave the squish for your tires!

Be sure to check out my post on Winter Cycling Pants for Fatbiking. Subscribe so that you won’t miss new posts from the Stay Warm, Ride Happy series.


A big FAT thank you to the women who took time out of their busy and full lives to contribute to this post!!

Happy Trails!



¹Professor Michael Tipton, professor of human and applied physiology at the University of Portsmouth

Join the Fat Bike Girl Community

Find inspiration for your next adventure and get the latest gear reviews! 

You have Successfully Subscribed!

Share This