Price: $5,600 (race kit); $3,200 (frame only) Weight: 27.9 lbs (as tested); 6 lbs (frame only) www.YetiCycles.com
A year and half ago, when I first stole a ride on Yeti’s 152-mm travel aluminum SB-66, my immediate reaction was to accuse the staff at Yeti of callous selfishness and exclusivity. Now that I’ve spent significant time on the SB-66 C, I’m standing my ground on that charge. Of course, I mean it in a most complimentary way.
Since its introduction, the SB-66 has won a shelfload of awards from editors on all sides of the planet, and the full carbon SB-66 C is all that and more. With its own high modulus carbon, Yeti shed 1.5 pounds from the rather heavy alloy frame. At 6 pounds, it’s now competitively light in the 150-mm trail bike realm. Even so, it’s an appropriately stout frame with burly chainstays and thick replaceable bash guards at its most exposed points.
In a very Yeti-like bravura, the SB-66 C and its Switch technology are boldly different from other dual-link suspension designs. What’s different about Switch technology is an eccentric mechanism at the main swing arm pivot above the bottom bracket. The eccentric link turns, and at a critical point, it switches direction as the suspension moves through its travel, effectively changing the location of the virtual pivot point, rate of chainstay growth and wheelpath. This also helps maintain a linear leverage ratio throughout the stroke.
At the beginning of the suspension stroke, the pivot is positioned so the eccentric link is moving in a rearward (counterclockwise) motion, creating a solid pedaling platform with a high rate of chainstay growth. Chainstay growth is desirable at this point because is counteracts forces on the suspension, keeping it from bobbing or sagging out.
As the suspension travels deeper into the stroke, the eccentric pivot reaches a flat spot before it begins to rotate in a forward motion (clockwise). Here, Yeti’s goal was to create a more responsive midstroke by keeping the rider higher in the travel (a larger sweet spot, if you will) until a bigger hit is encountered, at which time the suspension will be ready for it.
About 100 mm into the travel, the eccentric pivot starts to rotate in a clockwise direction, pulling the swingarm with it, drastically slowing the rate of chainstay growth and allowing the suspension to work more freely for the remaining portion of the stroke, providing a plush bottomless feel.
Since the concept of full-suspension bicycles emerged from a primal desire to ever improve our level of enjoyment on the trail, engineers have been trying to perfect the functionality by balancing all of the elements: pedaling efficiency, small-bump compliance, big-hit capability, weight, optimal wheelpath, chainstay growth and active braking (did I forget anything?) to create the ultimate trail-riding machine.
In effect, Yeti has found a way around the elusive game of identifying the sweet spot for a pivot point, which is inherently a compromise. Rather, its eccentric pivot allows the virtual pivot point and the relative chainstay growth to be optimized throughout the travel by switching directions of the pivot point’s migration. Switch technology is a true innovation.
Appropriately applying this technology, Yeti built the SB-66 C for big mountain rides, and the geometry has a distinctly downhill lean with a 66.7-degree headtube angle (with a Fox F34 150-mm fork). The 13.5-inch bottom bracket is just right, providing adequate clearance while keeping the center of gravity low and tight.
When compared to a handful of similarly aggressive trail bikes, the SB-66 C is long. The medium frame has a 24.1-inch effective TT and a reach of 16.3 inches (more than an inch longer than a medium Specialized Enduro, Ibis HD or Pivot Mach 5.7 C). The extra length in the front end contributes to a 45.2-inch wheelbase (again, one inch longer than comparables). For me, this took a little adjusting to on the trail but the result is an extremely stable bike that can be punched into rock gardens and threaded through twisted nests of slippery roots without scrubbing speed or concern for undesirable consequences.
The long cockpit and overall fit of the bike proved to be a great balance: It was much appreciated on the unavoidable occasions when I found myself slogging up a 3,000-foot climb to get to the goods. Slowness in response or compromised agility was never an issue. The more I got used to the fit, the more I liked it for its stability and overall versatile ride qualities. The geometry and fit of the SB-66 C carefully balances desirable traits found in both cross-county and trail bikes.
The new Fox CTD adjust shock and F34 CTD 150-mm fork are a perfect match on the SB66. In climb mode, the SB-66 rides with surprising responsiveness. Switch the shock to trail or descend mode and the suspension becomes incrementally more active and ready for anything you throw at it.
The switch technology has a tendency to keep the bike’s geometry true throughout the suspension travel, so handling is pleasantly predictable, and the feel on the trail is very natural. Six inches is ample travel for a trail bike and from the mid-stroke to its bottom end, the suspension felt bottomless and controlled. There was no harsh ramp-up at the end—the SB66 rallied in ever more demanding conditions.
Every aspect of the frame is well-thought-out. It has sleek splines on the BB shell to accept removable ISCG 03 or 05 chain guide mounts, internal cable routing on the rear triangle, 142-mm x 12-mm rear thru axle, tapered headtube, and cable stops for a height adjust seatpost. The nature and simplicity of the switch design and its sealed pivot hardware create a clean, strong design with all of the moving parts tucked neatly out of reach of mud and debris.
The SB-66 C is available as a frame only or with three build kits (enduro, race or pro), each of which I’d describe as competitively priced with high-quality components … but not perfect. Our test bike with the race kit came with a standard rear derailleur and a triple crank, which made it nearly unrideable; dropped chains were epidemic when riding the bike to its potential. We added a Shadow Plus derailleur, and it effectively solved the problem. When contacted, Yeti’s staff informed us the Shadow Plus derailleur would be available as soon as they get them in stock. Any self-respecting trail rider will also want to add a dropper seatpost, and I encouraged a 2x10 drivetrain option for all the kits.
Yeti’s crew is famous for their lunch ride in the rugged hills of Golden, Colo., and the SB-66 carbon is built to give them an unfair advantage over any victims they might overtake during the ride. Yeti’s crew selfishly built the SB-66 for themselves—presumably so they could wreak havoc on the big mountain terrain they all love to ride. Luckily they are willing to share the bounty, and we are all beneficiaries: The SB-66 C is a dream bike for those who like to earn their rewards and cash in on huge mountain terrain.