The world of mountain bikes seems to be evolving at an exponential rate these days. Blame the introduction of global communications and manufacturing technology that are serving to accelerate development in this industry and many others, if you want. Or blame elves. Whatever you attribute it to, it's producing high tech marvels of engineering, but also dirt simple factory rigs like this fantastic Niner ROS 9 Plus 3 Star Complete Mountain Bike, and for that alone, we're grateful. The ROS 9 Plus's frame splintered off of the standard ROS 9 frame family, which itself was spawned from Niner's original SIR 9 steel hardtail platform. The ROS's aim was to dig deeper into big lines and enduro type terrain, with slacker frame geometry oriented around longer travel forks. The ROS 9 Plus, then, takes that frame and widens the rear triangle enough to accommodate the so called 29 Plus rim and tire standard that's growing in popularity, thanks to its just ride sizing that splits the difference between fat bike fatties and standard 2 ish inch wide traditional mountain bike tires. The result is a fast, playful, and relatively light 29 Plus ready steel hardtail frame on which a wide variety of riding would be very welcome. Here's where the dirt simple part comes in: the refreshingly sparse build that doesn't sacrifice any of the frame's readiness. Sure, it could be even dirt simpler, with a single speed drivetrain, and maybe a coaster brake, but you can buy your own ROS 9 frame and build up that machine. This one comes with a SRAM X1 drivetrain and Niner's own chro mo steel fork. In conjunction with the tough 4130 frame, it's a strong but supple combo that will let you feel the trail without giving up the compliance you want to tackle the big stuff. In short, it's a dream machine for anyone from weekend warriors to junior varsity masochists, or just anyone looking for a good, fun, fast mountain bike.