Yeti's SB6 Carbon XTR Complete Mountain Bike replaces the much beloved SB 66. While we hated to see the 66's jersey officially retired, the fact that the SB6 was already winning World Cup events before it was even released made a compelling argument for why it was time for the 66 to bequeath its flagship status. The SB6's geometry takes steps toward the longer and lower ends of the spectrum, and the revamped Switch Infinity suspension sits higher for an overall ride that's more enduro er. Given the popularity of Yeti's Switch Link design, which is also entering retirement, and the literally pivotal role that suspension plays in enduro cycling, it's only appropriate to begin any discussion of the SB6 by touching on the differences between Switch Link and the all new Switch Infinity in order to illustrate why the perfectionists at Yeti felt a change was necessary. When you get past the 30% stroke while really pushing Switch Link's limits, you may experience a momentary harshness under rapidly successive big hits. The Infinity replaces the Link's sinuous travel arc with a linear plane of motion, so it changes direction without getting caught in the minute dead spot that produces that harshness. Of course, 95% of all riders won't ever push the Switch Link hard enough to experience this dead spot, but Yeti being Yeti went ahead and fixed it, anyway. For those of us who are our own mechanics, Yeti also simplified maintaining the Switch Infinity by including easily accessible grease ports, which do away with the need for time consuming rebuilds. Other than those two changes, the suspension systems are fairly similar. Like the Switch Link, the Switch Infinity slider travels upward under the first phase of compression, when the SB6 is settling into its sag point. As the rear end compresses deeper, the direction changes, and the DH inspired slider travels down toward the bottom bracket shell to maintain a steady pedaling platform. Deep in the stroke, it works in conju...