RIDE QUALITY
The Yeti SB 5.5 has a lively feel with some of the best acceleration in the test. It was surprisingly nimble and agile at speed, allowing the rider to avoid obstacles almost instantly, making this bike a blast to ride in the singletrack, although you do have to be on your game at higher speeds. The Yeti-designed Switch Infinity suspension system and the 29” wheels did an amazing job at smoothing the small bumps, giving this bike a flowy feel. And when the big hits came, they were soaked up seamlessly with minimal momentum loss. Plain and simple, this bike is incredibly fun.

STIFFNESS-TO-WEIGHT/POWER TRANSFER
Yeti has a unique suspension system with the Switch Infinity where the pivot actually moves throughout the curve of the suspension, raising up in the low-end and dropping down in the high. This gives the Yeti SB5.5 strong anti-squat characteristics that translate into superior pedaling performance. Acceleration was excellent for a long travel bike with the rear end stiffened up when hammering on the pedals, transferring most of the energy into forward momentum. Our model was the Turq series, which meant that the frame was half a pound lighter than the regular carbon version while still maintaining the outstanding strength and stiffness. The result was a quick and lively feeling bike.

CLIMBING/EFFICIENCY
One of the best traits of the Yeti SB 5.5 is its climbing ability. The relatively steeper 66.5º head tube angle eliminated some of the front wheel lift and sluggish steering found in the other Enduro bikes. The chainstays have been kept short at 17.2”, thanks to the 1×12 system, eliminating the front derailleur, which allows the rear wheel to tuck back under the rider, helping to prevent wheel slip. Out-of-saddle climbing, while never a joyous endeavor, was almost pleasant on the Yeti, as the suspension stiffened once the extra torque hit the drivetrain. Of course, as with all the bikes in this test, there is no suspension lockout, so seated climbing is invariably the preferred option.

DESCENDING/HANDLING
As was to be expected; the steeper head tube angle on the Yeti SB5.5 did make for a less relaxed downhill style. Fortunately, this bike was easy to shift around at speed making it easy to avoid tight spots with a little body English. Manualing took a little extra planning as well, however the big wheels and big front suspension made a missed wheel drop a non-issue, as the bike steamrolls through the rough without losing valuable speed. As mentioned before, you do have to be on your game on this bike when going fast downhill: It was the only bike in the test where I accidentally landed heavy in the front. The 800mm bars—while a bit wider than we’d prefer—helped slow the steering. And despite the tight trails where we rode, the benefits of the extra control outweighed the negatives of possible bar strikes. Plus, on that front-heavy hit those big bars and big suspension came in handy, absorbing much of the shock of the landing, helping prevent any front wheel slip or twist, and possibly saving my collarbone.

COMPONENTS: DRIVETRAIN, SHIFTING AND BRAKES
Yeti made some very sound decisions when choosing components for the Yeti SB5.5. The drivetrain is handled by SRAM X01 Eagle components with its 1×12 gearing, complete with a carbon xo crankset, which at the moment has no real competition. It also comes with Guide RS brakes that provide unparalleled modulation. This ability to gently feather your braking could mean a few precious extra seconds in a race situation. It also makes braking on loose gravel less bowel loosening (sorry, but it’s true!). This was the only bike in the test equipped with the Fox Transfer dropper post, which was a welcome change from the Reverb found on some of the other SRAM-equipped bikes. One of the best features of the Transfer is its remote button, which was a simple lever with dimples for grip. It had the best action of all the droppers in the test by far. Suspension is handled with a Fox Factory 36 Boost on the front with a Fox Factory Float X—paired with the Fox Switch Infinity—on the rear. One concern with the Yeti’s complicated suspension is that there are four more seals that could wear out, probably resulting in more maintenance down the road. The wheels were built on DT Swiss 350 Boost hubs with 30mm XM 481 rims. These wider rims provided a wider contact patch with the ground with minimal weight penalties. The carbon bars were Yeti’s own, with an 800mm width.