First Ride: Yeti SB165

The word 'news' is an oddly old-timey pluralization of the word 'new,' as in 'things that are new.' So, in that sense, I wouldn’t really call the introduction of the SB165 'news.' Sure, the bike itself is new, but let’s be honest. It’s not news. We all knew it was coming. Anyone who followed last year’s release of the SB100, 130 and 150 must have predicted this bike’s arrival. And I bet most of them predicted it pretty accurately. You start with an SB6 and give it all of the hardware updates made to the SB4.5 and 5.5.

The Basics

Those updates include but are not limited to: guided internal cable routing, an integrated carbon headset bearing interface and an innovative two-piece shock extender. Next, while you’re down there at the linkage, you add about 10 millimeters of travel and rework the leverage curve to be more progressive but also straighter for a more supportive mid-stroke. Then, give it some geometry updates similar to those made to the 4.5 and 5.5, which, in this case, would be around 40 millimeters longer in reach, 20 to 40 millimeters lower in standover, a degree-and-a-half slacker in head angle and 4 goddamned degrees steeper in seat angle. Throw an in-triangle water-bottle mount on it, and you’ve got yourself an SB165.

Of course it’s not that simple, but it’s no surprise that the SB165’s updates were conceived pretty much simultaneously with those of the SB100, 130 and 150. The market has been a little gaga over 29ers in recent years, so the big-wheeled bikes took precedent. But now that it’s 27.5’s turn, we have to unpack those updates in a whole new context.

Big Geo, Small Wheels

When we ran the SB150 through the Bible of Bike Tests gauntlet, we all remarked on how it encouraged us to ride farther over its front end. The long reach and slack head angle meant that, unless we leaned in, there wasn’t enough weight on the front tire for it to sink its teeth into the trail. The same is true on the SB165, but on 27.5-inch wheels, that commitment offers rewards beyond just more traction and more speed. On this bike, it offers precisely what would make you choose smaller wheels in the first place: More fun. 

I’ve been called out in the past for drawing a distinction between speed and fun. “Speed is fun,” the internet tells me. Point taken, but that doesn’t mean they’re the same thing. One wins races and the other does not. The role wheel size plays in this debate is nothing new, but it’s a little different on the SB165. When I was gunning for it, my mind on the clock, my eyes wide and my elbows pointed, the SB165 seems to have equal focus on speed and fun. With a slack 180 millimeters up front, I knew there was always a healthy buffer between me and utter disaster. I did end up with four volume spacers in the fork, though. Not because I was bottoming out often, but to make that buffer just a little more healthy. Small wheels or not, it’s clear this bike’s stance is bracing for impact, not winding up for a triple lutz.

But what was happening behind me was a different story. Sure, this bike has 433-millimeter chainstays which are admirably snug given the 165-millimeters of travel and 2.6-inch tire clearance. Of course it’s going to feel nimble at the ankles. But there’s one other factor. A lead that I’ve buried at least three-banner-ads-deep in this web review. That coil shock you see isn’t just an option on a couple builds like we’ve seen from Santa Cruz, Evil and Orbea. It’s standard equipment on every build, because every build was built for it. 

Spring is in the Air

How well a bike will work with a coil shock is factor of its linkage’s leverage curve. A bike whose linkage maintains a similar leverage ratio throughout the shock stroke needs to rely on the natural progressivity of an air spring to remain supportive. But a progressive leverage curve can offer that same support even with a coil spring as long as it’s progressive enough. The simple way to measure that progressivity is by comparing the ratio of wheel movement to shock movement at the beginning of the stroke to that at the end of the stroke. For instance, if at the beginning of the stroke, the axle moves 20 millimeters for every 10 millimeters the shock moves, it’s got a 2:1 leverage ratio for that bit of the stroke. But let’s say at the end of the stroke, the shock moves 10 millimeters for every 18 millimeters the axle moves. That would give it a 1.8:1 ratio at the end of the stroke. The difference is 10 percent, giving that bike 10-percent progressivity. That’s about what Yeti’s SB100 has. More aggressive bikes like the SB130 have 12-percent progressivity. The SB150 has 15 percent. But this bike, the SB165, has 27-percent progressivity.

That means a lot of things, but back to our speed vs. fun scenario, it means you get the best of both worlds. When I’m going full speed on the SB165, the rear end is floating through high-speed chatter thanks to that buttery coil goodness. But if I want to give it a flick to break the rear end loose, or if I want to lean back and pop up, that energy does exactly what I want it to. While trail energy is disappearing into the shock, my energy is being redirected exactly where I want it. I was able to let the rear end dart back and forth, into and out of berms and across scree fields where traction can actually be a buzzkill. It’s something best achieved with a perfect storm of tight geometry, a stiff chassis and suspension that seems able to both read your mind and tell the future. 

Mind you, the entire trail was not made of those moments. For a mere mortal like myself, the stars have to align to compose the chaotic poetry that long-travel 27.5-inch bikes are meant for. More skilled riders will be able to treat the SB165 like a wakeboard in situations where I’ll be lucky to treat it like a life raft. But those moments did happen, and they happened more and more frequently the more I got used to doing what the 165 is best at doing.

The Part Where We Talk About Climbing

Surprisingly, it makes it easy to do more of it. I didn’t expect the closing paragraph to be about climbing, but here we are. Combining Yeti’s chosen 77-degree seat tube angle with that straight progressive leverage curve and coil shock lead to an unbeatable mix of support and sensitivity. Of course, Switch Infinity plays quite a role here. We’ve praised the unique floating lower pivot for years, but this is something new. Because of that steep seat angle, you sit high in its travel where the shock is especially sensitive. I won’t say I never missed my 29-inch wheels when climbing the SB165 through deep rocky chunk, but I didn’t miss them for long. The shock is always ready to yield to an impact, but never to pedal input. Whether I need to or not, I tend to like switching my shock into a climbing mode on smooth uphills, but I dare say I kept my fingers off it unless I was on the pavement. I never thought I’d say this about a coil-sprung long-travel 27.5-inch bike with the head angle of a DH sled, but the SB165 is downright practical. But don’t let that fool you It’s also both fun and fast, whether or not you might think the two are mutually exclusive.