Skip to main content


Naturally, all of WRC’s staffers are avid cyclists and obsessive bike enthusiasts.  If it’s got two wheels and can be ridden, someone here has experience with it, guaranteed.  From BMX to velodrome, from gravel to downhill, from mountain to road– we’ve done it all.

There is one cycling discipline, though, that has only a few devotees: Fat biking in winter.  We’ve been talking about general winter riding in the WRC Journal recently, and today we focus on this most intriguing cycling discipline with our resident winter fat bike authority, sales manager Steu Fish.

-Ed.

WINTER fat biking

By Steu Fish

I’ve been riding mountain bikes and road bikes since the late 1990s. In 2012, as I transitioned away from snowboarding, I needed a replacement winter activity so I got into winter cycling. In 2013, I got my first dedicated fat bike, a Surly Pugsley, and I’ve progressed through the years to my current modern stable. 

Over this span, the bikes and gear have improved and been refined, and likewise my experience has accumulated. I still have people who look at winter fat biking with curiosity and ask questions, and it is fun to share the insight I have gained.

origins

Fat bikes for use in snow have their origins in Alaska, for both transportation needs as well as recreation. Before the advent of dedicated parts, riders often had to craft their own homemade rigs. One can still find internet pictures of rims welded together and side-by-side tires to maximize grip and flotation on snow and ice.

Soon enough, popularity demanded the bicycle industry take note. Manufacturers began designing and making proper fat bike goods, from dedicated wider rims and tires to the frames that accommodate them. The goal was to have a bike that gives a more stable footprint on slippery surfaces, but also float on snow.

The concept is simple and adapted from snowshoes: increasing contact surface area to stay on top of the snow. If you have hiked in a snowy winter landscape you have experienced this. The difference between snowshoeing easily across the surface and post-holing to your knees in just boots can make the difference between enjoying the activity and not!

definitions & regional differences

Numerous northern native peoples of the world have developed multiple words for snow to describe the varied types encountered and the uses for each. In regards to fat biking in snow, the same practice could be applied. As you venture out to various locations from the front range of the Rockies further up into the interior mountains, snow conditions can and do change and trail expectations should change as well.

My experience is focused on the high-elevation desert and alpine climate of the Rocky Mountain Region. Here you will find cold dry air with snow that is typically high-volume/low moisture. Additionally, often after snow storms, the weather turns sunny during the day with cloudless evenings that get significantly colder. These are known as thermocycles, an important and useful phenomenon that assists in making very light, powdery, unrideable snow pack down into fun snow packed singletrack.

The snow here is vastly different from what you may have experienced in the Midwest or Eastern parts of the US, where snow remains much wetter at those lower elevations. Tire sizes will need to be carefully considered.

tires & pressures

As with all fat biking, especially in the lower moisture snow we have here, tire size and pressure are critical to maximize float. It’s also critical to minimize damage to the trails.

With regards to the issue of trail conditions and tire pressure (and tire size for that matter) it can be an important consideration both for your enjoyment of the trail as well as others. The front range from Colorado Springs to the Wyoming border typically get enough pedestrian traffic as well as other fat biker traffic that the trails get packed fairly quickly after a snow. Combine this with more focused sun, thermocycles, and time, and the trails might be ridden successfully even with a plus-size-tire bike as was discussed last week. (Though I would argue that a bike equipped with fat tires of 3.8” width or more is less physically taxing and much more fun!)

With regards to tire pressure it may be obvious that as tire size increase tire pressure decreases. For example, a 28c road bike tire may run at 90psi. A 38c gravel bike tire might run at 50psi. Mountain bike tires in the 2.4” range are probably, depending on rider weight and conditions, being run in the 20-25psi range. A 3.0” plus sized tires run in the 15psi max. 

Fat bikes tire pressure adjustment is critical. For tires 3.8” to 5.0” on snow (again adjusted slightly for rider weight) you will find best results down to even 3psi. The lighter, fluffier, deeper the snow the more you will want and need to experiment with lower pressure.

Additional recommendation at this time is to get your wheels set up tubeless. Remove a couple of pounds of tubes off your bike AND allow you to more confidently run appropriate low pressure. On dirt when riding my full-fat tires I may bump up to 10 psi but on snow I will be at 7 psi on hard pack snow and down to 5 psi on fluff (note I am 210 lbs then add gear and a 37 lb bike)

Once we move deeper into the mountains, tire size increases not only by suggestion but also by requirement. Many locales where winter fat biking is more common -- from Winter Park to Breckenridge to Leadville’s to Happy Jack above Laramie, Wyoming -- will range their direction on tire size from strong pleading to absolute demand. They simply do not want riders trashing their groomed trails with less than a 3.8” wide tire. 

Again front range trails can be a different story, but for high-volume/low moisture groomed snow of the high elevation trails the key is to get maximum float so the bike rolls and doesn’t bog down into the snow, destroying the trail for other users.

trail etiquette

Jefferson County Open Space has recently released a graphic you will be seeing at trailheads soon.  Click the image to get the viewable version.

riding gear for body & bike

When it comes to clothing, many riders may find that their winter gear from other cycling disciplines can be successfully carried over to winter fat biking.  Nevertheless, there are some concerns specific to winter fat biking of which we need to be aware.

body

As with any winter cycling pursuit, layering is the key to comfort. You will be really kicking out the body heat on climbs and once the downhill starts the cold can really set in. Be prepared to take layers of clothes on and off throughout the ride.

Head & Eyes

Wear a helmet with the desired level of warmer underneath, such as a skull cap or balaclava.

Sometimes conditions will warrant goggles, but most often in our climate sunglasses will work just fine.

Hands

Gloves are supremely important in winter fat biking and a selection of five to seven different types, thicknesses, and fabrics is not unheard of for a proper winter fat biking arsenal. Additionally, bar mitts or pogies are awesome for maximum hand warmth.

feet

Boots for use with flat platform pedals, or clipless winter boots with clipless pedals. There are also combo pedals with a clipless fixture on one side and a flat platform on the other. 

Winter-specific cycling boots, in addition to being warmer if clipping in, will insulate the cleat with the heat of your foot thus minimizing melting snow, which then refreezes into an ice block making it very difficult to clip back in.

HOW DO I CARRY ALL THIS STUFF?

Frame, seat, and handlebar bags provide ample storage space for moving clothing on and off. Some riders like backpacks, but know that a backpack may make your back sweaty, which can lead to challenges when the day gets colder.

WHERE DO I LEARN MORE AND FIND THE COOL RIDES AND RIDERS?

The best bit of information I can give to someone getting into fat biking here in the Rocky Mountain region is to use Facebook. There are numerous pages to connect with the various region’s fat bike groups. These are imminently useful in learning about where to ride and updates on conditions, and also to ask questions of the membership group on issues with which you may be seeking experienced opinions. We ALL have opinions and would love to share to ensure your winter fat biking experiences are as fun as possible!

Get out there, and happy fat biking!