Purpose-built for bikepacking, the new stainless steel Otso Fenrir has a unique geometry that’s designed for both drop bars and flat bars, clearance for 29 x 2.6” or 27.5 x 2.8” tires, and a lot of mounts. Find details and a handful of photos here…

Taking its name from a giant wolf in Norse mythology that was destined to devour the sun, the Otso Fenrir has a lot to live up to. But Otso claims it’s their most versatile rig to date. The new Otso Fenrir is built around a custom-butted stainless steel frame with loads of mounts and adjustability, and according to Otso, it’s built for bikepacking on rides like the Tour Divide or any other mixed terrain route you might dream up. What makes it unique is a geometry designed for use with either drop bars or MTB flat bars. In short, this means it has a longer reach than most drop bikes, and a shorter reach and higher stack than most mountain bikes. Read on for all the details.

Otso Fenrir

The Otso Fenrir has a tire clearance for up to 29 x 2.6” or 27.5 x 2.8” tires, plenty of mounts, and adjustable geometry thanks to its Tuning Chip rear dropout system. Here are the specs:

  • Custom-butted austenitic, corrosion-resistant stainless steel frame
  • Available in five sizes from XS to XL
  • Tuning Chip allows it to be built with gears or singlespeed
  • BOOST Hub spacing (148 x 12 and 110 x 15 — with ENVE Mountain Fork)
  • 68° head tube angle, 75° seat tube, and 88mm of trail
  • Comes stock with a carbon ENVE Mountain Fork with three-pack mounts on either side and a reversible dropout chip for adjustable rake
  • Accepts a suspension fork with up to 100mm of travel
  • Internal seat tube routing for a cable-actuated dropper post
  • Rack and fender mounts
  • Otso Fenrir
  • Otso Fenrir

As with Otso’s other bikes, the Tuning Chip allows riders to adjust the bike’s chainstay to ever so slightly change the geometry. This is essentially a dropout with three fixed positions. The Tuning Chip can change the wheelbase by up to 20mm, the bottom bracket height by up to 4mm, and the head tube angle by 0.2°. The front position is made for agile handling with a shorter wheelbase, higher bottom bracket, and steeper head tube angle. The back position of the Tuning Chip is made for a stable, confident ride on sketchy terrain, with a longer wheelbase, lower button bracket, and slacker head tube angle. Based on past experiences with Otso’s bikes, hanging positions of the Tuning Chip is pretty easy and takes 5-10 minutes.

Otso Fenrir

The Otso Fenrir’s geometry was essentially designed to accommodate drop bars with a 50mm stem or MTB bars with an 80mm stem. This allows owners to customize the bike to their riding style. According to Otso, when built with drop bars, the Fenrir “rides like a gravel bike with extra helpings of capability and confidence.” With MTB bars, it’s “lively, fast, and rides like a capable 90s XC bike.” Both configurations are meant for about any road or trail on the map and to carry all the gear necessary to get there.

  • Otso Fenrir
  • Otso Fenrir
Otso Fenrir Geometry

The Fenrir is available as a frameset for $2,400 with the ENVE Mountain Fork and a complete via the custom bike builder their website or at Otso dealers. All build options, from handlebar type to wheel size, and from tires to drivetrain, can be selected on the custom bike builder. The base builds are as follows, both starting at $3,900.

Otso Fenrir Drop Bar Build

  • Rear derailleur: Shimano GRX 810, 11-speed
  • Shifters: Shimano GRX 600 mechanical, 11-speed
  • Chain: Shimano HG-11X
  • Crankset: Race Face Aeffect
  • Grips: Cork handlebar tape, black
  • Fork: Enve Carbon MTB Fork, 15mm thru axle
  • Cassette: Shimano SLX, 11-46t, 11-speed
  • Brakes: Shimano GRX 600 hydraulic
  • Handlebar: Lithic Corundum aluminum compact drop-16° flare
  • Wheels: Sun Ringle Duroc 3, 110x15mm front and 148x12mm rear hub spacing
  • Tires: Maxxis Aspen 29 x 2.4″

Otso Fenrir MTB Build

  • Rear derailleur: TRP G-Spec TR12, 12-speed
  • Shifters: TRP G-Spec TR12, 12-speed
  • Chain: KMC X12 12-speed
  • Crankset: Race Face Aeffect, 32T Wolf Tooth chainring
  • Grips: Wolf Tooth silicone grips, black
  • Fork: Enve Carbon MTB Fork, 15mm thru axle
  • Cassette: SRAM GX, 10-50t, 12-speed
  • Brakes: Magura MT4 hydraulic
  • Handlebars: Lithic
  • Wheels: Sun Ringle Duroc 30, 110x15mm front and 148x12mm rear hub spacing
  • Tires: Maxxis Aspen 29″ x 2.4″

As you may have noticed, the main photo is of one we just got in for testing. Stay tuned for a review, and in the meantime, learn more over at OtsoCycles.com.



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