Otso Voytek Review: Shapeshifter

Digging through this site, you won’t find a whole lot about fat bikes. We do our best to share new bikes when they’re announced and also provide some event coverage in the winter fat biking scene, but for one reason or another, we don’t regularly review fat bikes. This mostly comes down to the fact that most of us don’t require the floatation offered by massive tires where we live, especially as many of our team members flee the cold each winter, so they seem like overkill for much of our riding. But, when RJ Sauer invited me on a multi-day winter bikepacking trip last winter, I scrambled to get one ready.

Finding a suitable (and interesting) bike for the occasion was a top priority. We usually only test bikes that we are personally interested in or we believe will be relevant for our broad reader base. I find the more interested I am in a bike, the more detailed the review ends up being. I decided I wanted something lightweight, relatively new, and suitable beyond winter fat biking expeditions. That’s where the Otso Voytek came in. Just a few months earlier, the Voytek had gone through a major overhaul—it’s first major update since its release back in 2016. More tire clearance, additional mounts, and some fresh new paint jobs had me dreaming of shivering on the side of the trail with RJ. Unfortunately for us, spring came early in British Columbia, and the trip never happened. But I didn’t let that stop me from getting up to some other mischief for this long-term review.

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The Otso Voytek is unique among the world of fat bikes. Owing to its narrow Q-factor and XC-inspired geometry, it’s equally suited to running massive 26 x 4.6″ tires in the winter or 27.5+ or 29+ mountain bike wheels in the summer. I’ve heard of many Voytek owners racing winter events in the cold months and then with a simple wheel swap and flip of the rear dropout tuning chip, running it as a mountain bike or bikepacking rig in the summer. It’s built up around a carbon frame and fork, your choice of 26″, 27.5″, or 29″ wheels, modern specs, and features that make it look pretty appealing as a bikepacking rig.

• Highlights (XL, Rigid)
• Angles: 69° Headtube, 73° Seattube
• Chainstay: 430-450mm
• Bottom Bracket: 83mm Press-Fit
• Hub specs: 15 X 150mm (front); 12 X 177mm (rear)
• Seatpost Diameter: 30.9mm
• Max Tire Size: 29 x 3.0″ / 26 x 4.6″
• Price: $3,990 USD

In 2021, the Voytek was updated with a redesigned fork and more tire clearance. The latest fork has three-pack mounts on both legs for cargo cages or racks and can also clear massive 26 x 5.4″ tires (the frame is maxed out at 26 x 4.6″). Described as a “bike for all seasons,” Otso’s online bike builder lets you dial in every aspect of the build, including the drivetrain, touchpoints, tires, and more. It can be run with a 120mm suspension fork or their stock carbon fork, with or without a dropper post, and it’s only compatible with 1x drivetrains. For those who like options, the Otso Voytek delivers.

Frame Specs and Features

At the core of the Voytek’s versatile platform is its 183mm Q-factor (distance between the outside of the crank arms). Thanks to Otso’s relationship with their sister company Wolf Tooth Components, the Voytek uses a custom offset CAMO chainring system alongside a 83mm bottom bracket to keep the pedal stance tight and tire clearance at a maximum. It also features Otso’s Tuning Chip rear dropout, allowing the wheelbase to be lengthened or shortened by up to 20mm, which also changes bottom bracket height by up to 4mm and head tube angle by +/- 0.5°. In the forward position, the Voytek is fast and responsive, and in the rearward position, you’ll have more control and stability—especially in snow.

According to Otso, the frame will clear a 26 x 4.6″ tire with an 11-speed drivetrain in the rear position of the Tuning Chip rear dropout system. The chance of chain rub with a 4.6″ tire increases with a 12-speed drivetrain when the chain is on the biggest cog. They recommend a max 4.2″ tire for those who run 12-speed. As mentioned, the latest fork can clear a 26 x 5.4″ tire on a 100mm rim, and the Voytek has clearance for any 29 x 3.0″ or 27.5 x 3.0″ tire both front and back.

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The Voytek uses 150x15mm / 177x12mm thru-axles, a 30.9mm seatpost with internal dropper post routing, press-fit bottom bracket, and a mix of internally and externally routed cables and hoses. In addition to the fork mounts, there are two standard bottle mounts, mounts under the downtube, and additional provisions for a custom bolt-on frame bag, including the option from Revelate Designs that Otso offers as an add-on. There are even two extra mounts under the downtube for a bolt-on fender, such as the PDW Mud Shovel. While the Voytek doesn’t have upper or lower rear rack mounts, you can purchase Tuning Chips with threaded rack mounts, an Axiom Streamliner Fatliner rear rack, and a seatpost clamp with rack mounts for an additional $100. All of the Tuning Chip small parts are also available to purchase if anything gets lost or damaged.

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Building a Custom Voytek

One of the major benefits of purchasing a bike through Otso is their custom Bike Builder. For a bike with so many options and potential configurations, it’s nice to see how things can be pieced together for making a purchase—especially because the Voytek isn’t cheap. Otso let me pick out every aspect of the build, right down to stem length, accent color, drivetrain, chainring size, handlebar, tires, and grips. Having so much control over the build is a real selling point in my eyes, and the process makes the entire experience feel truly custom.

The build we ended up putting together was based around a Shimano XT 1×12 drivetrain, Magura MT4 hydraulic brakes, a carbon SRAM handlebar and cranks, a selection of Wolf Tooth small parts, and a rigid seat post. Planning for a winter trip, Otso sent both a fat 26″ wheelset and a 29+ wheelset for me to try out. The 26″ wheelset was built up using SUNRingle Mulefut 80 rims with 45NRTH Dillinger 5 26×4.6″ (front) and Vanhelga 26×4.0″ (rear) tires. The 29″ wheelset was based on SUNRingle Duroc 36 rims and Panaracer Driver PRO 29 x 2.6″ tires. I spent a month or two riding the fat wheels before transitioning to 29+ mode for most of the summer.

Build Kit

• Frame Voytek Carbon
• Fork Voytek rigid carbon
• Crankset Race Face Next SL, 32T Wolf Tooth CAMO
• Shifter Shimano XT
• Cassette Shimano XT, 10-51T
• Derailleur Shimano XT 12-Speed
• Chain Shimano XT 12-Speed
• Bottom Bracket Race Face PF107
• Rims SUNRingle Duroc 36
• Front Hub Lithic sealed cartridge, 150x15mm
• Rear Hub Lithic sealed cartridge, 177x12mm
• Tires Panaracer Driver PRO 29×2.6″
• Brakes Magura MT4
• Brake Rotors SRAM Centerline 180mm
• Handlebar Race Face SixC
• Stem Alloy 60mm
• Seatpost Alloy
• Saddle WTB Volt
• Headset Wolf Tooth Performance
• Grips Wolf Tooth Fat Paw

Although the final build depends on what parts Otso has available, they are great at only offering high-quality components, so you can guarantee you won’t end up wishing you had more. The same can be said for the build Otso sent me. I’m a fan of Shimano XT 12-speed, which performed flawlessly during my testing period, including some seriously nasty conditions and some packrafting. This was my first time using Magura brakes, and I quickly grew to appreciate their unique lever shape and feel. I was excited to try the Panaracer Driver Pro tires, which hit a sweet spot for speed and grip in the 29 x 2.6″ platform. The complete XL build weighed a hair under 28 pounds, which to me seems pretty impressive, although that didn’t always translate to the ride quality. More on that later.

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Ride Impressions & Angles

In fat bike mode, the Voytek plowed through pretty much anything I threw at it, eating up root gardens and technical climbs to the point that it felt like I was riding a full-suspension mountain bike. The lightweight frame and massive rubber (when running super low tire pressures) made for a lively and responsive ride quality that almost had me forgetting about how much work it was to roll fat 26″ tires. Even in the longer wheelbase position, it popped and carved through singletrack naturally and efficiently, dispelling any preconceived opinions I had about XC-inspired fat bikes. The oversized downtube and carbon construction results in an incredibly stiff platform, making tire pressure more important than ever. Once I found that sweet spot, i.e. tubeless and low pressure, I found the Voytek could be both comfortable and responsive. With too much tire pressure, I found the stiffness of the frame and fork jarring on rough terrain, especially with 29″ tires.

Having the ability to run big 26″ tires will surely be appreciated by some, but 29+ is the unofficial tire size of bikepacking and one I was eager to experience on the Voytek. Set up with 29 x 2.6″ tires, it sat a little higher, rolled quicker, and handled low-speed, technical riding without the “self-steering” characteristics that often come with fat bikes. The low stack and long front end really do make it feel more like an XC bike than a sluggish fat bike or 29+ expedition rig. By the numbers, it’s not actually so far off from the Otso Fenrir that was released last year. It might not have the extra-long reach and slack head tube angle we’ve come to expect from the latest generation of hardtail mountain bikes, but it definitely fits the bill as an efficient, and unapologetically versatile, four-season mountain bike.

I’m not sure if it was a combination of the slightly wider pedal stance, higher bottom bracket, long wheelbase position, and low tire pressures, but the Voytek lost a lot of that lively feel on long climbs. Unless I was charging up short pitches, it felt more at home on slow and steady climbs. On some of the longer climbs, there were few times when I’d check my rear tire to ensure it wasn’t flat. The stiff frame and fast-rolling tires certainly had the potential to roll quickly and efficiently uphill, but my desired tire pressure usually didn’t mesh well with that.

I was most surprised by the Voytek’s ability to charge through tight and punchy singletrack. According to Otso, the Voytek’s chainstays are the shortest in the world for a fat bike, and it shows. At 430mm in the shortest position, they are right on trend with other modern hardtail mountain bikes we’ve reviewed (and even shorter than some of them), which keeps traction at an all-time high and makes the rear end easy to move around beneath you.

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Bags, Rafts, and Bikepacking

The Voytek feels great at a slow and steady pace when loaded up with gear for bikepacking and packrafting. Everything really came together when I started getting out on loaded rides and campouts. Part of me felt like the Voytek’s lightweight build should zip around all types of terrain, but when you add on a bunch of camping gear and a pack raft, I lost some of those expectations.

It’s easy to load the Voytek up thanks to its generously sized main triangle, top tube bag room, and downtube mounts. Between the perfectly fitting Revelate Designs frame bag, a big Klean Kanteen strapped underneath, and my big JPaks top tube bag, I could confidently head out knowing I had plenty of room for snacks, water, and other gear. In this partially loaded setup, I sometimes felt I should strap on some aero bars and go attempt a fastest-known-time on the Tree to Sea Loop. It has rigid endurance racing rig written all over it, but I’ll leave that up to the real athletes. I never felt out of place connecting gravel and pavement together with trails for long rides, and it reminded me a lot of the early days of bikepacking on my rigid Surly Krampus—but much lighter.

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The faster rolling 29 x 2.6″ tires transform the Voytek into an awesome do-everything bikepacking rig. You get most of the benefits of plus-sized riding, namely traction and the ability to run low pressures, but you’re left with generous amounts of clearance for mud and debris when things start getting weird. I also noticed the space at the top tube/seat stay junction made for a great handle when lifting the Voytek over fallen trees or other obstacles.

While out bikepacking, I tried several types of setups. Most recently, during my Sea to Sky Trail scouting trip with Nathan, I had it set up to be light and fast with a minimal Rockiest Gondola saddlebag and the new JPaks Refugi handlebar harness. For some cooler trips this spring, I used my trusty Porcelain Rocket Mr. Fusion saddle bag and mixed in a Bags by Bird Piccolo for extra carrying capacity. I never considered removing the frame bag, which was a pleasure to use thanks to its burly construction, stretchy Cordura zipper panels, and various pockets and sleeves for organization. This was actually the first bike-specific Revelate Designs frame bag I’ve used, and I was really impressed. The fit, overall quality, and attention to detail were all top notch.

So, Who’s it For?

The Voytek might be for you if having a lightweight carbon fat bike is your number one priority. As a fat bike, it’s a fairly specific, somewhat niche, bike. Its XC-inspired geo is fun and undoubtedly conducive to fast winter ultra events or playful trail riding in snow and sand. Paired with a super stiff frame and fork, it feels responsive and snappy, just like a cross-country bike should. Add on a rear rack and a riser bar, and you’ve got yourself a year-round bikepacking rig that’s totally capable of handling snow, mud, sand, and whatever else you feel like plowing through. If you’ve considered the Salsa Beargrease, perhaps the most comparable bike out there, then the Voytek should be high on your list. Keep in mind that the Beargrease has a fixed rear dropout, threaded bottom bracket, more mounting points, and fully internal cable routing, so it’s a slightly different beast.

If you’ve made it this far, then the Voytek’s 29+ capabilities might just be the cherry on top. The 29+ platform is fantastic for bikepacking. Big 29″ tires roll over pretty much anything, can be run at low pressures for comfort and traction, and although there are’t a huge number of true 29+ tires available these days, 29 x 2.6″ is also pretty good. Set up as a 29er, the Voytek handles like an XC mountain bike but has all the features you’d expect from a purpose-built bikepacking bike. It’s a fun, versatile platform that could be equally suited for daily riding and fully loaded bikepacking expeditions. The Voytek is a good reminder that 29+ isn’t dead…yet.

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• Model / Size Tested: Otso Voytek, Size X-Large
• Weight as tested: 27.8 pounds (12.6kg) with flat pedals
• Place of Manufacture: Taiwan
• Price: $2,790 USD (frame only) / $3,990 USD (Base Build)
• Manufacturer’s Details: OtsoBikes.com

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