Alaskan based 9:ZERO:7 has been producing fat bikes since 2004. They aim to build bikes suitable for “#AllConditions,” which is exactly what I’ll be testing with this 29+ Tundra build. I’m curious to see if the Tundra feels as at home in the widely varying terrain of Southern California as it does in it’s wintry homeland. The Tundra is built around a lightweight aluminum fat bike chassis, and sports some updates from it’s predecessor, the Whiteout; including shorter chainstays and head tube, a suspension corrected carbon fork, and 300 grams of weight savings. The trail-ready 69 degree head tube angle and shorter stays promise a modern, playful ride.
Out of the box, the Tundra was quick to set up. The first thing I noticed was the elegantly sloped hydroformed aluminum tubing, giving the frame ample standover clearance. The Tundra comes equipped with stealth routing for a dropper post to help you take advantage of all that space. The drivetrain is primarily made up of SRAM GX1 components, and includes a 10-42 tooth 11 speed cassette.
The full bike ships with a 1x RaceFace Turbine crankset, although the frame does include routing for a front derailleur. My test model came with a 30 tooth front chainring, which pairs well with the wide-range cassette for loaded riding. Rounding out the controls, the Tundra utilizes SRAM’s Level T cross country and trail oriented hydraulics.
Despite being an aluminum framed bike, carbon components abound on this build, including a 760mm wide SixC riser bar and Next SL seatpost from RaceFace, and a suspension corrected 9:ZERO:7 fork.
The Tundra is a true fat bike frame, and is built around standard fat bike spacing for the bottom bracket and hubs (150 x 15mm front, 197 x 12mm rear). However, it’s just as happy to be set up as a plus bike for summer riding. For an additional cost of $400, the Tundra can ship with either a 27.5+ or 29+ wheelset instead of the standard 26” fatties. It should be noted that 9:ZERO:7 warns of increased pedal strikes with the 27.5+ option, due to the lowered bottom bracket. My test model came with a pair of Easton Arc 45 hoops laced to Sun Ringle hubs, and fitted with Maxxis Chronicles, set up tubeless by the manufacturer.
Despite being designed for a smaller diameter wheelset, the 29+ tires fit in the frame and fork like they were made for one another.
The frame is equipped with mounts in various locations, including two in the main triangle, one underneath the downtube, and a fourth set on top of the top tube. The mounts on the top tube utilize low profile bolts and can be used to hold a water bottle cage, Anything Cages, or even an integrated top tube bag.
This test bike arrived with a custom frame bag from Revelate Designs, which is a great addition for extended rides and bikepacking excursions. I’ll be rigorously testing this bike in a wide range of conditions throughout Southern California over the next two months, including at least one fully loaded overnight trip. So far, I’ve been happy with the overall design, build, and quality of this machine; but only time and trial will tell if it stands up to 9:ZERO:7’s claim of being built for #AllConditions. Check back for my follow up. The Tundra GX1 Starts at $2,399, to purchase head over to fatbikes.com
