To Switch Infinity… and beyond!
When I first laid my eyes and hands on the Yeti’s new SB4.5C, I couldn’t help but remember Buzz Lightyear’s famous tagline from the “Toy Story” movie: “To infinity… and beyond!” It continued to echo in my head during every ride, and I may have even yelled it out loud once or twice… though I will deny doing anything of the sort if asked.
Indeed, the SB4.5C – despite its name, which sounds like a library book calling number – is as far away from boring as one can get. It’s the third incarnation of elite American manufacturer Yeti’s superbike series (hence the SB). The 4.5 is the younger, cheekier 29-inch brother of the veteran, smaller-diameter SB5 and SB6.
29” carbon frame
Unique “Switch Infinity” rear suspension with 114mm travel
140mm of fork travel
Boost technology front and rear axles
Dimensions (frame size M):
Top tube – 605mm
Headtube angle – 67.4 degrees
Effective seattube angle – 73.3 degrees
Chainstay length – 437mm
Wheelbase – 1,1153mm
Weight (including sealant and pedals) – 11.9kg
Manufacturer geometry table
The SB4.5C boasts a high modulus carbon fiber main frame and swing arm, which grants it exceptional stiffness and tips the scales to an anorexic 2.45kg. The frame comes with integral chainstay and downtube guards. Furthermore, as per today’s standards, the cables and hoses are tucked inside the frame with precision that eliminates clatter and allowed us to focus on the beloved sound of tires on trail.
Yeti’s unique Switch Infinity system is situated above the bottom bracket and looks like a turbo charger designed for bicycles. It actually consists of two hollow Kashima-coated cylinders which serve as rails for the system’s slider, to which on of the swing arm’s axles are freely connected, to slide up and down.
What is it good for? Those who don’t like Switch Infinity claim it’s primarily a way around patented suspension links, since the system’s short movement could easily have been replaced by a traditional link, making it yet another virtual pivot twin-link system. Those who like it argue that the linear movement of the swing arm is what allows the SB4.5C’s suspension to excel as it does. Right or wrong, however, matters not in the argument – on the trail, the system proves extremely pedal-efficient and provided traction in most types of terrain.
And here’s a video explaining how Switch Infinity works:
What components stand out?
It’s hard to single out specific outstanding components in a bike that comes with almost all the high-end gizmos of modern mountain-biking; suffice to say that the SB4.5C’s spec was successfully tailored to its attitude. What deserves our attention is the Boost-technology compatibility of the frame, with a 148mm rear axle, and the Fox Factory 34 fork also with 110mm Boost-technology. The Yeti also comes with a SRAM X01 1X11 drivetrain, which shifts like a dream, has relatively light aluminum DT-Swiss wheels, SRAM Guide RSC brakes with significant stoppage power and modulation, a carbon Easton bar, and other treats. What we think should be included in a bike sporting such a hefty price tag are carbon cranks and/or rims.
On the trail
After wiping the saliva off the side of our mouths, we swung a leg over the SB4.5C and set sail. The riding position is very comfortable, though the cockpit is a bit short. On the first turn of the pedals, the bike launches forward with incredible lightness and ease. It’s important to note that before starting our test rides, we always calibrate the shocks and leave them in the “open” mode; the different functions are tested only later on. As such, we weren’t completely surprised with the Yeti’s pedaling efficiency, which is becoming a staple of the new general of Enduro/AM bike category. Our amazement began when we first climbed out of the saddle for a sprint – the suspension stiffens up and helps shoot the bike forward, like opening the thrust on a jet engine. There are plenty of efficient suspension designs on the market, but one that works as well both sitting down and standing up in a sprint is harder to come across. I can think of only one other bike I tested this year that left me with the same impression.
When the SB4.5C was first launched, it took a lot of flak from critics who complained that despite the modern AM geometry and components that fit the category, the suspension felt too stiff and lacked the suppleness demanded by its riders. Yeti responded by shipping out an upgraded version with a different shock calibration, which allows for a softer, more progressive suspension. The model we tested did not receive this upgrade, and indeed, in the more violent trails the suspension felt as if it could not hold its own and send powerful feedback to the rider’s legs. However, this happened only rarely, and overall the suspension behaved phenomenally given its relatively-short 114mm of travel.
Steering and control
The SB4.5C felt stiff, sharp and extremely responsive – largely a result of the super-stiff frame and Boost-technology hubs, frame and fork. The headtube and wide handlebars provided added confidence while descending, and in rough terrain the extra-short chainstays enable superior maneuvering. Flying through rock gardens, the Yeti felt confident and kept its line, despite the suspension’s relative lack of depth.
Long rides and climbs demonstrated the light-as-a-feather package, and the light wheels, efficient suspension, and pedaling efficiency merged with the comfortable riding position to keep the rider fresh and sharp even after several hours in the saddle. That said, the SB4.5C is far from playful, and failed to unleash the inner madman in me – not in chasing Strava KOMs and not in time spent airborne, though my run times on it were generally better than my usual averages.
Another point of contention in the SB4.5C design is the large gap between the fore and rear suspension (140mm vs. 114mm, respectively). Here I stand beside Yeti: the bike felt extremely balanced. The Fox Factory 34 fork with 110mm Boost technology worked like a charm, refused to dive during braking or to bob, and allowed me to stick to my line of choice. In choppy terrain, this compensated for the rear suspension’s relative lack of travel, and even when it couldn’t keep up, the fork kept me confident.
The Yeti SB4.5C is a new generation bike designed to do it all and do it well, effectively vying to become the only steed in your stable. The relaxed geometry, effective performance, and light-weight design provide very good results. The short rear-travel design trend proves itself yet again (there are plenty of other 29-ers with 120mm rear suspensions out there), both in efficiency and in its ability to cope with a wide spectrum of riding terrains.
The SB4.5C will caress its rider both on epic journeys as well as hard, technical rides. The ease at which they perform is nearly snobbish – everything is done without breaking a sweat.
Who does it suit? First and foremost, people with deep pockets! If you’re one of the lucky ones, who also likes diverse trails and is looking for a pair that can do it all, you’ve just found your gold pot.
Here’s how the Yeti performs on Iceland’s mountain ranges:
|FRAME WEIGHT:||5.4 LBS (2.45 KG)|
|SIZES:||SM MD LG|
|COLORS:||BLACK GREEN TURQR.|
|SHOCK:||7.5” X 2.0”B.|
|WHEEL:||148MM X 12MM (BOOST)|
|SB4.5c (FRAME)||5.4 LBS 2.45 KG||$3400|
|SB4.5c GX||27.1 LBS 12.29 KG||$5599|
|SB4.5c X01||25.9 LBS 11.75KG||$6899|