Otso Arctodus Ti Puts a Lighter Spin on Their Biggest Fat Bike

Already planning your winter adventures? If your plans include riding bikes on varying snowpack in remote locations, you’re gonna need flotation. The kind of flotation offered by a fat bike like the Otso Arctodus. Introduced just over a year ago, the Arctodus is Otso’s take on a fat bike meant for bigger tires than their incredible (and updated) Voytek. And now, you can have one in titanium.

The biggest news here is the addition of titanium for the frame material, whereas the original is still available in Chromoly steel. Like the steel Arctodus, the Arctodus Ti is optimized to run the biggest fat bike tires available without sacrificing q-factor.

Big Tires, Narrow(er) Q-Factor

Q-factor is the width of your crank arms, which typically has to increase to clear bigger tires. Otso has always been a proponent of running narrower-than-average q-factors on their fat bikes, the Arctodus Ti is no different. Thanks to a 5mm offset of the rear wheel, they can run cranksets with 20mm narrower q-factors while still clearing 1×12 drivetrains. The result is the ability to run 26 x 5.05″ or 27.5 x 4.5″ fat bike tires without feeling like you’re straddling a horse.

Continuing with their Tuning Chip dropout system, you can adjust the wheelbase by 20mm, BB height by 4mm, and the head tube angle by +/-0.5º. Further adjustments to the head tube angle can be gained by running a Wolf Tooth GeoShift Angle Headset. Options are available in +/1º or 2º, giving the bike a head tube angle range of 66.5 to 70.5º

Otso Arctodus Ti Geometry

Further geometry numbers include a stock head tube angle of 68.5º and seat tube angle of 74º across all four frame sizes. Otso says the trail figure of 94mm is responsible for increasing flotation, and the BB height is raised to help while pedaling in deeper snow. The frames are also suspension-corrected to run a 120mm travel fork if desired.

Frame Details

No modern off-road bike is complete without a dropper post, or at least the ability to run one. So you’ll find a port near the BB to run the cable if so. The frame is shaped to allow for plenty of storage in the front triangle for frame bags. There are also a number of mounts including a 4-pack on the downtube, and matching 3-packs on each fork leg. Rear racks can be added using the frame mounts or through the Tuning Chip mounts, and the frame is compatible with PDW or SKS fenders.

The frame uses a 100mm threaded BSA bottom bracket, and achieves the 205mm q-factor number with a Race Face Aeffect crankset. Claimed weights for bare frames are 2429g (S), 2487g (M), 2550g (L), or 2621g (XL).

Pricing & Availability

Available now, the Arctodus Ti starts out at $4,695 for the base build with Shimano SLX and aluminum components. The frameset is also available for $3,795. Using the Otso custom bike builder, you can customize most of the components and accessories including the accent color.