Salsa wasn’t first out of the gate in the fat bike market, but the brand can largely be credited with taking what was at the time an oddball curiosity and applying a number of smart design features that gave the segment life. If the Surly Pugsley is the Model T of fat bikes, the Mukluk is the ‘32 Ford—a platform that can be built or customized a hundred different ways and it has spawned a big-tire bonanza in the industry.
This bike is my personal 2014 Salsa Mukluk 2, and while the basics are still there, I’ve made a number of changes in order to extract all the performance I could.
Highlights
6066 aluminum frame
26-inch wheels (with 82mm wide rims)
100mm fork travel
44mm head tube
68.5-degree head angle
73-degree seat tube angle
60mm bottom bracket drop
Adjustable chainstays, 447mm-464mm (17.6 to 18.2 inches)
100mm, threaded bottom bracket
170mm quick release rear dropouts
$2,399 MSRP (base price)
The Mukluk starts with an aluminum frame made with double butted and heat treated 6066 tubing. While it is naturally lighter than steel, it is also more corrosion resistant, as many fat bikes live a tough life in winter.
Where it does differ from a traditional aluminum frame—and significantly so—is in some key dimensions. First off, in order to clear the huge tires, the rear dropouts have been widened to 170mm. This of course requires a special hub, though shortly after the Mukluk’s introduction the 170mm spacing quickly became common, and is still found on many fat bikes. Since then the latest crop of fat bikes have moved on to an even more massive 190mm hub to clear even larger tires.
The dropouts are built around Salsa’s excellent Alternator design, found on many of the brands’ bikes, and can be adjusted fore and aft to change the effective chainstay length from 17.6 to 18.2 inches, or they can tension a singlespeed or internally geared hub drivetrain. They also keep the axle in a fixed position in relation to the brake caliper for easier wheel removal in singlespeed mode. Salsa also sells aftermarket dropouts that can accommodate a 177x12mm thru-axle or a Rohloff hub.
Also stretched beyond the norm is the bottom bracket shell, measuring 100mm wide. Though it uses standard, threaded cups, the crankset must have an extra-wide spindle. This extra-wide Q factor is worth noting, as smaller riders or those with sensitive knees may find themselves unable to adapt.
The main triangle is built from large, ovalized tubes that add strength and stiffness, especially warranted with the ability of the heavy wheels and tires to twist the frame. It is adorned with three bottle cage mounts, including a triple eyelet set on the downtube that can mount a bottle cage in a high or low position, or be used with Salsa’s Anything Cage—a sort of jumbo bottle cage that can carry oversized items like a stuff sack.
The head tube angle measures in at 68.5 degrees, and while it may seem like an average number to trail bike riders, keep in mind that many fat bikes are designed with much steeper head tube angles to counteract what some assume is their “slow” steering.
But I wanted to ride the Mukluk fast, so I added a RockShox Bluto suspension fork and a dropper post to see if the bike really could be a viable alternative to a standard mountain bike. In fact, beyond the wheels, tires and crankset, nearly every piece on this Mukluk has been swapped in favor of something I chose either for personal preference or performance.
On the trail
I’ve ridden the Mukluk through snow and sand, over mud and rock. It certainly has its advantages in terrain that is soft or loose, and the amount of traction available from the tires’ huge contact patch is indisputable. My testing grounds varied from the rolling hills of Pennsylvania to the steeper terrain of the Oregon Cascades.
The first thing anyone would notice as they climb aboard the Mukluk is, of course, the massive wheels and tires. While the stock Surly Nate 3.8 tires are the higher quality 120 tpi version, they are still portly. As you can imagine, getting up to speed takes a little more effort than normal, though once up and rolling the inertia of the wheels becomes part of the equation. It’s best to learn to use it to your advantage rather than try and fight it.
If you’ve ever ridden a 29er back to back with a 26-inch bike, it’s easy to see how the larger wheels create an almost unfair advantage when pointed straight. Obstacles that require care with smaller wheels are suddenly non-existent as the wheels get larger. The sensation of riding the Mukluk is similar, but perhaps even more pronounced. The overall diameter of the 26x3.8 wheel and tire is about the same as a standard 29-inch wheel and tire, giving you great roll-over capabilities, and the extra width means it is less susceptible to getting caught between rocks or sliding down off roots.
The cost of that monster truck ability is the loss of any sort of micro-control over where those tires go. On fast, technical trails where a tiny, split-second movement can make the difference between hitting your line or missing completely, the Mukluk has only one course of action: ramming speed. The heft comes in to play on flow trails as well where the wheels are reluctant to transition side to side.
In the early days of fat bikes the idea was floated that a four-inch tire was like having four inches of suspension. Having ridden the Mukluk with the stock rigid fork, I can emphatically say that the idea is bunk. Do your 2.5 inch tires give your bike an extra 2.5 inches of suspension travel? I didn’t think so. So when RockShox released the Bluto fat bike fork last year it was a sign that things were about to get a whole lot smoother.
And it’s true that the Bluto give the Mukluk significantly more control when the trail gets bumpy, and it reduces the amount of basketball-like bounce that the massive tires create, but only to a degree. Careful attention needs to be paid to tire pressure as too much can result in a lot of undamped rebound over rough sections of trail, especially quick, successive hits; but too little air pressure gives the bike an unnerving amount of squirm and naturally raises the likelihood of pinch flats.
Build kit
Many of the stock drivetrain and control pieces have also been swapped out in favor of more aggressive or more durable units. The Easton Haven bar and stem use a 35mm interface for added strength, and the carbon handlebars’ 760mm width is appreciated for keeping that massive front wheel pointed in the right direction. The 25.2-inch effective top tube of my size XL frame keeps the cockpit roomy enough to run a short stem and keeps the handlebars high.
Stopping duties are handled by a set of Shimano SLX brakes that are a few generations old, but still perform as well as new products from other brands. The stock SRAM X7 10-speed shifters were swapped in favor of thumb shifters largely because they are easier to shift with heavy gloves on in the winter and a 9-speed era Shimano XT rear derailleur was found in the parts bin to pair with them.
While the bike ships with the Thomson seatpost pictured here, it is most often ridden with a unique dropper post from 9Point8, a small brand from Ontario, Canada. The Pulse model uses a mechanical actuation via shift cable and moves in 5mm steps. Each soft push of the remote drops the saddle 5mm to its next indent and continues for a total of 100mm of travel. Pushing hard on the remote will allow the saddle to move freely to any point in its travel, stopping at the nearest indent when you release the lever.
It is an interesting design that merges characteristics of both the infinite-travel dropper designs like a RockShox Reverb and the 3-step designs like those of Fox or Specialized. It takes some getting used to, but largely performs as intended.
While the stock Surly Holy Rolling Darryl wheels have held up well against impacts, even with their single-wall design, they are unimaginably heavy compared to traditional mountain bike wheels. A lighter wheelset that could be set up tubeless would likely make a huge difference in the bike’s capabilities, with the potential to drop several pounds of rotational mass.
Long term durability
While I have been riding the Mukluk with the suspension fork for the past six months, in that time a recall was issued for the stock aluminum fork and a replacement was sent right away. The glowing orange metallic finish has held up well and the Alternator dropouts have never slipped or loosened. The Surly Nate tires are also wearing slowly, a nice sign considering how expensive fat bike tires are to replace. The aluminum Mukluk frame and components come with a three-year warranty against manufacturing defects for the original owner.
What’s the bottom line?
While I had high hopes that the Mukluk could be transformed into a capable mountain bike, the results have been mixed. Despite its heft it is still fun to ride, as long as you’re not in a hurry. It draws a lot of attention on the trail and adds some variety to spice up old, well-known trails. That said it has a long way to go before it can compete with suspension bikes or even hardtails. It isn’t for everyone, but for the right rider it can still be a lot of fun.