Sure, mid size wheels may be generating a lot of hype in mountain biking, but big wheel evangelist Niner doesn't seem to mind. And when looking at the freshly revised WFO 9 Mountain Bike Frame, it's easy to see why. The original WFO was arguably the first truly shredable wagon wheeler, and the latest version builds strength upon strength, with a renewed focus on being the fastest bike at your local Enduro race track. In other words, it's lighter, more responsive, and more refined than its predecessor. And even if you're not racing, the WFO's aggressive handling will have you looking at your favorite trails in a whole new light. The WFO established itself early on as an immensely capable bike when ridden wide freakin' open, and the latest version will crystallize that reputation. For starters, Niner relaxed the head angle to 67 degrees, which puts it on the very slack end of the spectrum for big wheeled bikes. And while this change enhances the high speed stability, it was important to keep the WFO responsive across a wide variety of trails. Accordingly, the chainstays were shortened to a more moderate 17. 4 inches, and the top tube lengths have also been reduced by 20mm across the size range. This gives it a lighter handling feel, and keeps the wheelbase from getting unwieldy. Rounded out with a slightly lower bottom bracket, the new WFO has all the stability of its predecessor, with greater versatility. With a generous 150mm of rear wheel travel, the WFO is clearly optimized for descending fast in hairy terrain. But you may be surprised to find how responsive it is when you get on the gas. That's thanks to Niner's CVA suspension platform. Unlike other designs, CVA is optimized for the increased bottom bracket drop inherent in 29in wheeled bikes, which helps to maximize efficiency. It tends to ride high in the travel, with a controlled mid stroke, which keeps the WFO stable through rock gardens and snappy when you get on the pedals. But one of the oft overloo...