Is it a gravel bike? A drop bar 29er? Or something else entirely? When it comes to the nomenclature surrounding these modern touring bikes, I often scratch my head, pondering an answer to this question. My usual inclination is to envelop these bikes under the umbrella of “adventure bikes” but then this bike landed in my lap. The Otso Cycles Fenrir is aligned with bikes like the Kona Sutra ULTD and the Moots Baxter but Otso did something different – i.e. better – than its competitors. The Fenrir took it up a notch and has utilized boost spacing wheels, which in my mind, put this in the drop bar 29er category.
I’ve had the Fenrir for a while now, have taken it on an overnighter, and have ridden some of my favorite mixed terrain routes here in Santa Fe with it. On washboarded sandy roads to singletrack, doubletrack, and gravel, the Fenrir is a hell of a bike and one that I really resonated with, so let’s check it out in detail below…
In Norse mythology, Fenrir was a monstrous wolf, the size of a locomotive train who was said to bring about Odin’s death during Ragnarök, the end of the world. It would make sense that Otso would name this bike Fenrir since it is larger than any of its other drop bar bikes. If the Warakin Stainless is a German Shepherd, then the Fenrir is indeed a gigantic wolf by comparison.
In the world of metal bikes, steel and aluminum are probably the most common, with titanium right behind them. Nestled in the family of metal bikes is stainless steel, which offers a robust and unique riding experience when compared to its closest kin, steel, and the other high-end metal, titanium. Stainless is lightweight like titanium but offers a unique resonance and stiffness that isn’t as harsh as aluminum. Yet, stainless is much more springy than normal steel. Stainless won’t corrode as easily thanks to Chromium (the alloying element used in the production of stainless steel to make it so robust and resistant to corrosion) and stainless can be polished to a mirror-like finish, rather than being plated or painted as evident here with the Fenrir. In short, stainless is more resistant to corrosion, can be polished to a mirror-like finish, and is a hardier material for a bike like this.
The Fenrir is essentially a hardtail mountain bike, designed for an 80-100mm travel suspension fork, or a rigid suspension-corrected fork like the ENVE Mountain fork seen here. Because of the mountain bike chassis, you can build the Fenrir up as a flat bar rigid or hardtail MTB with an 80mm stem or a drop bar with a 50mm stem. The two stem length options resolve the different reach dimensions required by the different cockpits, which is especially important when utilizing a wide dropbar like the Curve Cycling Walmer bar.
So What’s So Different About the Fenrir?
Bikes like the Fenrir are aligned with bikes like the Moots Baxter and Kona Sutra ULTD in that they utilize a mountain bike tire size and drop bars. Where the Fenrir differs from the two is the fact that it utilizes proper mountain bike wheels, which are boosted, rather than gravel wheels which are non-boosted. Fenrir also uses an MTB q-factor to align the driveline with the boosted wheels. This is why I believe the Fenrir is a proper drop bar 29er whereas the other two bikes mentioned are essentially beefed-up gravel bikes.
Yet, the Fenrir goes a step further than simply putting drops on your hardtail. Most hardtails don’t come with rack or fender mounts, or the necessary cargo bosses used in touring accouterment. It’s this reason — in my opinion — that “bikepacking” has become so popular. When you don’t have rack or cargo bosses, you have to rely on bikepacking bags for carrying your cargo because they utilize velcro or cargo straps to attach themselves to your frame.
In my mind, one of the differences between a touring bike and a bikepacking bike is these exact provisions. Bikepacking = bags with straps. Touring = racks/light racks/struts. Again, ATMO. This nomenclature helps me keep the phenotype of various bikes and thus, their genus/species in order when describing them in reviews like this. Of course, just like in nature, permutations arise.
The Fenrir literally throws any number of combination of touring possibilities your way with a plethora of cargo bosses and provisions for racks and fenders. It allows for a traditional rack like this Old Man Mountain Great Divide rack to be used with panniers like the Buckhorn Bags panniers, which I’ve been digging, while also offering up cargo cages on the ENVE Boost Mountain fork to be used in conjunction with a bar bag like the Fab’s Chest and rack struts like a Pec Deck.
For me, the two components to any bicycle geometry equation begin with the head and seat tube angles. Of which the Fenrir touts a 68º HTA and a 75º STA in its un-sagged, rigid form as reviewed here. With a suspension fork, you’d have to consider sag into these dimensions. Another factor that plays into a bike’s perceived stability is the chainstay length (wheelbase too!) and finally, the bottom bracket drop.
Now here’s where it gets tricky with the Fenrir. This bike has a tunable rear end thanks to the Tuning Chip which offers 2cm of adjustment for chainstay length which also impacts the overall wheelbase of this bike. The bottom bracket drop is also slightly affected by this, but moreso when running a suspension fork on the Fenrir. Coincidentally, for the singlespeeders out there, the Tuning Chip can also be converted to singlespeed using Otso’s SS conversion Tuning Chip.
The Fenrir is very XC in terms of its geometry but the reach numbers have been altered to coincide with the drop or flat bar option. You couldn’t have a long reach dimension and still offer drop bars as an option…
Otso and its parent company, Wolf Tooth, do such a great job of detailing their products. The Fenrir features a matte-blasted logo on the downtube and top tube, an in-house designed chainstay yoke that allows for up to a 42t chainring, and Otso logos on the Tuning Chip dropouts. Otso even upgraded the Fenrir with orange-colored anodized Wolf Tooth Torx and Allen bolts that match the orange Wolf Tooth headset perfectly. The cargo bosses are in the right spots, allowing you to place your bottle cages however you please and utilize bolt-on frame bags. I really loved being able to fit two Widefoot cages and large Nalgenes in this frame! There’s even routing for a stealth dropper post!
The Shimano SLX 46t rear cassette and 42t Wolf Tooth Chainring make for a great gear range that can be easily increased with a smaller chainring.
When Otso reached out to me about reviewing the Fenrir with the question: “flats or drops, rigid or hardtail?” I figured the readership would be most interested in the rigid drop bar 29er build and to be honest, I was as well! While I love hardtails perhaps more than any other bike model, I can’t help but be intrigued by the evolution of the modern drop bar 29er. Especially since I’ve never spent a lot of time on a true-to-form drop bar 29er with boost wheels and an MTB q-factor. What I wasn’t expecting was the build kit Otso sent with the bike.
I’ve spent some time on Shimano’s GRX kit in the past and, truthfully, I really enjoyed it on this bike. In terms of a cable-actuated drivetrain, it’s hard to beat with its crisp and precise shifting. The only riding experience that one-ups GRX is an AXS “Mullet” setup like I reviewed on the Baxter with SRAM in the Inyo Mountains of California. Back when I reviewed the Baxter on the Steamboat to Fort Collins Ramble Ride, it utilized a 2x Shimano drivetrain.
The Fenrir isn’t specifically designed for flat-mount brakes but Otso sent a flat-mount GRX kit on it, using adaptors. Personally, I’m not a fan of flat-mount brakes as they tend to “walk” when they heat up, causing brake rub, and are limited to 160mm rotors. I’d prefer 200/180mm rotors on the front/rear of a bike like the Fenrir because when you descend a rutted fire road for thousands of feet in elevation loss, 160mm rotors aren’t enough for my fat ass and all my bougie camping gear. For this review period, however, I only took the bike loaded up on relatively flat terrain so the 160mm rear rotor wasn’t ever an issue.
Acting as the cornerstone for this build spec are the massively wide Curve Cycling Walmer bars. These things are condor-wide and for a big guy like me, it made the XL Fenrir feel like a touring La-Z-Boy. With the Fenrir’s short reach number, I was in the most comfortable touring position I’ve ever experienced. I wasn’t super upright but was far from being stretched out. It fit me like a glove and offered a riding experience unlike any other tourer I’ve had the pleasure of throwing a leg around.
“Touring on a sofa” is how I jokingly referred to the riding experience of the Fenrir to Otso’s marketing manager in a text thread and it’s true! Touring is about comfort, about enjoying both the ride quality and your surroundings. That’s perhaps why I refrain from calling all forms of bike camping “bikepacking” which was derived in a competitive — i.e. non-comfortable — environment. Touring should be comfortable and bikes like the Fenrir offer up a ride quality perfect for such activities.
What makes the Fenrir so unique is its stainless steel chassis. Unlike titanium, which can get pretty noodly when loaded down for a tour or camping trip, stainless is much stiffer laterally. For instance, with a rear rack and loaded-down panniers, I experienced very little side-to-side sway when I was out of the saddle, climbing up punchy roads. Some people refer to this as a dog’s wagging tail effect.
Instead, the Fenrir maintains its precise handling on rough terrain and especially when pedaling out of the saddle. Anecdotally speaking, if traditional steel has a stiffness rating of 6, aluminum a 9, titanium a 5, I’d rank stainless in around 8 out of 10. Yet, when the bike is unloaded, the stainless steel frame offers a wonderfully pleasant pedaling experience. It’s light on the pedal stroke and smooth on descents. I still prefer the loaded and unloaded ride quality of titanium, but stainless steel is on another level. Honestly, most people will feel more comfortable on stainless, as compared to titanium, when it comes to a fully-loaded bike.
The geometry of the Fenrir creates a pleasant ride across the board. The slacker front end carries weight well when off-road touring, or descending steep trails, and the steeper seat angle makes climbing singletrack a bit easier as it puts your body closer to the bottom bracket. The frame material softens what can be a normally “stiff to the butt” riding experience of such a steep seat angle. Keep in mind, the Fenrir can also be built as a hardtail MTB, so Otso was clearly erring on the side of maintaining its trail-ready capabilities. The wheelbase feels stable as well, without being overly floppy or hard to steer. The short chainstays have a lot to do with this.
Nitpicks? Critics? Improvements?
One of my least favorite parts of bike reviews is finding critiques for the sake of it. I’m an experiential rider, who focuses on the quality of the ride, not things like weight, aerodynamics, or the like traditionally focused on by other bike media. Yet, I understand that one of the benefits of sending bikes out for review is for the brand’s own PR&D. Sometimes media outlets can point out things that in-house designers and engineers didn’t think about in the design process or catch in the development stages. Well… I rarely say it but the Fenrir hit all the marks for me. I wouldn’t change a single thing on this bike. Period. Ok, maybe a smaller chainring for mountain climbs!
Last Points and the Takeaway
I love big, burly “expedition” style bikes and the Fenrir has got to be the dreamiest I’ve ever ridden when it comes to a drop bar tourer. The bike itself is sleek with its polished stainless chassis and neat color hits thanks to Wolf Tooth’s anodized hardware. The wide Walmer bars make it ride like a comfortable sofa, the big tires absorb rough terrain and the stainless steel offers up a unique ride quality. I’m a bigger person, at 6’2″ and 190 pounds and the XL fits me perfectly. The bike, as reviewed here in “gravel” mode — void of cargo cages and the rear rack — weighs in at 28lbs including the pedals and bottles. Not bad!
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