The SB140 has a nice upright position for climbing with the 77-degree seat tube angle and 460mm reach on the size medium. The firm pedaling platform means that I didn't feel the need to lock out the rear shock on anything but the most onerous of paved climbs. Despite that efficient pedaling platform, there's good traction on climbing trails scattered with rock obstacles and slippery roots and when fire roads get steep with loose gravel.
While the front end feels like it's a long way in front of you on the SB140, it tracks well. Although I did find the length of the bike noticeable when making my way around tight switchbacks. I also found that it took a bit of an effort to maneuver the SB140 up big square-edged steps. This was especially noticeable during my time in Moab, Utah. While there's enough standover height for shorter riders and Yeti's size range for the medium is 5'5" - 5'11", it definitely feels bigger than mediums from some other brands, and from Yeti's previous generation, so I would keep that in mind if you're between sizes.
All in all, while you're not going to win any climbing segments on the SB140, it's an incredibly dependable climber and it will get you to the top of the climb with plenty of energy left for the fun part. Descending
Despite riding it for months, every time I took the Yeti SB140 out, I was shocked by how fast it could go when you pointed it down a straight section of trail or a rock slab. Yet even when I felt like I was going Mach 10, I felt in control and the bike felt stable and composed.
Some of the most fun I had on the SB140 was when I took it to the Whistler Bike Park. Normally, I prefer tech trails to A-Line laps, but on the SB140 I felt so comfortable at speed, in bermed corners, and in the air, that I wanted to keep lapping jump trails all day and whipping the back end quickly around turns. The orange speed demon was forgiving with mistakes and didn't blow through its travel easily, despite having much less travel than most bikes in the line-up for the chair lift.
Back home in Squamish, I found that the one place that the SB140 struggled a bit more was on steep technical descents with tight trees and lots of cornering, where even the strongest of riders have to grab fistfuls of brakes to slow down. The bike didn't feel as composed and stable under braking, and the smaller wheels didn't make their way through chunky holes and over roots the same way that a 29er would.
While you could race the SB140, a better option for a racer is Yeti's SB150 with slightly more travel and bigger wheels, and the SB130 is a better all-rounder for big days in the mountains. My favourite laps on the SB140 had lots of alternate line options, wider bermed corners, and good lines of sight so that I could hoot and holler without my fingers on the brake levers. Dream rides on it are party laps in the Whistler Bike Park and riding in the middle of a pack of friends in a social race.