For the majority of the last 20 years in mountain biking, the trend in frames has been to incorporate lighter and smarter suspension systems to help smooth out the trails. A dedicated few, however, have stuck by their hardtails, touting lower maintenance and a superior, more natural connection to the trail that translates into greater confidence than feel robbing rear shocks can ever provide. For hitting big lines and drops, of course, rear suspension has its place, but for those purists, hardtail bikes like the 2015 Niner ROS 9 3 Star X1 Complete Mountain Bike don't just do it well, they do it best. You'll notice that the ROS 9 looks a lot like the SIR 9 from which it's descended, but the burlier steel tubeset gets stronger welds and is far better equipped to handle bigger forks and wild riding styles. As a result, the ROS frame weighs in at 6 pounds, putting on the heavier side of the hardtail spectrum. But, as anyone who's ever walked back to the trailhead due to a broken frame can tell you, a little extra weight is well worth the peace of mind, especially when you're jumping that gnarly double for the first time. Weight and materials aside, a quick glance at the geometry sheet will confirm that the ROS isn't your average hardtail. Depending on your choice of a 120mm or 140mm fork, you'll end up with a 68 or 67 degree head angle, respectively. And in the world of 29ers, that's very slack perfect for going fast. Out back, the chainstays hover around the 16. 5 inch mark, with 5mm of foreaft adjustability courtesy of Niner's BioCentric bottom bracket. That keeps it turning on a dime, and makes full speed manuals a piece of cake. But it doesn't sacrifice stability with its roomy cockpit and low bottom bracket. Of course, a steroidal hardtail like this needs to be able to host parts that will keep up. That's where, for example, the 44mm head tube comes into play allowing compatibility with tapered forks. The 31. 6mm seat tube fits just about every dropper ...