To most people, the mention of a fat bike instantly brings to mind pictures of snow and ice. To others, fat bikes are used regardless of the conditions or season. That second group is exactly who the Fatback Skookum was designed for.
When it came time to design their all terrain/trail fat bike, Fatback was looking for something that would complement their stable of race winning adventure fat bikes. Something with shorter chainstays, slacker angles, and even room for more travel. Something exactly like the new Skookum…
Fatback has a long history of offering bikes that fit well into the adventure or racing realm of fat tires. With victories in almost every fat bike race you could think of on bikes like the original Fatback and Corvus as well as multiple course records, Fatback riders have proven their race and adventure pedigree.
As good as those other bikes are, though, FuzzyJohn wanted to offer something else to customers, but also to ride himself. The result is the Skookum, a 120mm travel trail fat bike that is equally at home plowing through snow as it is sending jumps.
The carbon framed behemoth is built around 197×12 rear spacing with a 100mm threaded bottom bracket that will allow 26 x 4.8″ tires without resorting to the wider 5″ fat bike cranks. Fatback isn’t the first brand to build big tire clearance around the narrower Q-factor cranks, but it’s a welcome addition. Unless you’re a big human the narrower (still wide by normal standards) Q-factor is much easier on the knees. In front of the bottom bracket is an integrated downtube protector to keep the carbon from taking a beating from the rocks that are sure to be flung up by the front tire. You’ll also find an integrated rubber chain stay protector plus a stainless steel chain strike plate to help keep the frame fresh.
I’m happy to point out that all of the frame appointments have a very high quality fit and finish – no sketchy dropout systems or parts. At the rear, Fatback makes use of their own QR thru axle, but it functions just as you would expect. Thread it in, tighten the lever. Combined with the well designed replaceable derailleur hanger, the back end of the bike is solid – which is important when you start launching the Skookum off lips.
All of the cable routing with the exception of the Stealth dropper is kept external. You can either use the provided clips or zip tie the tables into position and the cable guides allow a few different options for routing. Our review bike was sent completely unassembled (all in one box!) which meant we had to route the dropper line ourselves. The dropper housing has its own tunnel that leads it through the downtube and around the seat tube junction up to the seat post, but the bend to the tube by the bottom bracket made it a bit tricky to get the housing through. The trick ended up being to give the housing a bit of pre-curve, but also using a file to round the end of the housing so that the internal wires didn’t dig into the sides of the tube. After filing the housing a bit, it popped right through for easy installation.
Considering we’ve had fat bikes shipped to us in comically oversized or double boxes, Fatback’s ability to fit the Skookum into a single large box was impressive. We’re not exactly sure how the Skookum would arrive to various shops or consumers, but in this case I appreciate it when bikes come basically completely unassembled as it allows for a true pro build from the ground up.
During the build I took the chance to weigh a few of the individual components including the 1,590g (3.5lb) frame with the rear thru axle, and the Schwalbe 4.8″ Jumbo Jim Tires – 1,235g and 1,281g. This was also the first chance for us to check out the bolt on Maxle Stealth for the Bluto which drops the weight down to just 50g for the 150mm axle.
Completely built with the tires set up tubeless with sealant and without pedals, the medium (18″) Skookum came in at 29.32lbs (13.29kg). Not bad for a 4.8″ tire fat bike with a 120mm Bluto, dropper post, aluminum wheels, and a SRAM GX 1 drivetrain.
Available in “3 or 4 season” builds (4 season includes Gripshift and mechanical disc brakes since mechanical discs tend to be better in extreme cold) with four different wheel options, Fatback has put a lot more thought into the actual components than just weight and prices. Fat bikes pose interesting constraints on components which leads to very specific choices. Take the cockpit – Fatback specs carbon bars on their upper end bikes since the carbon won’t pull heat away from your hands like metal bars do. ESI grips are also used for their insulating properties as well as performance in the cold. They even went as far as to test multiple saddles to find one with a padding that doesn’t harden in extremely cold conditions. When temperatures drop below 0ºF, things don’t work quite the same as when it’s warm so it all has to be taken into account.
Our 18″ test bike came in the Chinook colorway and equipped with the SRAM GX 1 3 Season build and Mulefut 80 wheels and a price tag of $3,549. That includes SRAM Guide R brakes which performed OK in the cold – not my favorite winter brake, but not bad. Q-Factor is kept in check with a RaceFace Aeffect Cinch Crank with 30t direct mount narrow wide ring. I’ve really enjoyed all of the RaceFace fat bike cranks I’ve used and the Aeffect is no exception. Other details like the SRAM GX 1 drivetrain and KS Integra Dropper with Southpaw remote were great additions to the build. Overall the Skookum is incredibly well spec’ed with personal preference or local riding conditions being the only reasons that would inspire change. Offered in 16, 18, and 20″ frames, build kits include the Gx1 4 season for $3350, GX1 3 season at $3799, Sram XO1 4 season for $4500, and Shimano XT at $4999.
Even with a ‘3 season’ fat bike, you’re still going to freak out like a middle schooler during a snow day when the white stuff starts to fly, so I spent plenty of time on the Skookum during the winter months. The Skookum performs exactly as you would expect in the snow but with a few exceptions. To me, the geometry of the Skookum and the 120mm travel fork are right at the limit for something I would want to use in the snow. The longer travel fork lifts the front end of the bike which requires more of a conscious effort to keep the front end planted in loose snow. Any taller at the front and it seems like it wants to push, but the Skookum does a great job finding that limit and keeping things in check. The fortunate trade off is that with the longer travel and short 17.3″ chain stays, the bike’s a blast when it comes to technical descents – the kind of stuff where you aren’t quite sure what’s under that top layer of snow but it doesn’t matter. Some of my favorite rides on the Skookum were rides where you may not typically choose a fat bike as the weapon of choice. Don’t let the big tires fool you – you can go plenty fast even when there is no snow.
Honestly, the weakest link in the Skookum’s winter performance for me came from the Schwalbe Jumbo Jim tires. Obviously, tire preference is largely personal and depends greatly on your local conditions. More so with a fat bike tire it seems. There are many conditions that these tires work very well in, but our strange winter this year was not one of them. I found them to be fairly vague in the few times we had fresh snow, and unable to really grip when the snow started to get wet or icy. Riding trails back to back with different tires, I was able to clean sections on something like the 45NRTH Beist tires, but spun out on Jims. The Jumbo Jims seemed to be a great tire for more firm conditions – dirt, sand, etc.- so keep that in mind when building your bike. If I was getting the Skookum to be more of a trail bike the Jumbo Jims would be a good choice. If you’re spending more of your time in snowy climates, something with more bite might be the answer.
Over the course of testing, the Skookum saw snow of various types, sand, semi-frozen sand (which is one of the strangest riding surfaces I’ve encountered), mud, and dirt. Trail, and non. Inspiring confidence on almost any surface, the Skookum really shines in its versatility but also in its playfulness on aggressive trails. This really isn’t the bike if your idea of fat biking is slowly plodding along in the woods. But if you’re looking to push the limits of traction and suspension regardless of the temperature, the Skookum is indeed quite impressive.