Big wheels and big travel make for some speedy descents aboard the Pivot Firebird Pro XO1 Mountain Bike. Bred for the highest levels of enduro racing, the Firebird is our first choice for black diamond runs and technical mountain terrain. But since it's powered by an efficient DW-Link suspension platform and Pivot's legendary carbon frame, we don't hesitate to tackle big mileage rides deep in the forest, considering the Firebird pedals much more comfortably than other bikes in the enduro category. Equipped with 165mm of rear travel, a 170mm FOX 38, and a slack 64-degree head tube, it's pretty clear the Firebird's intentions are to get down the mountain as fast as possible. The DW-Link rear suspension uses a longer link that's inspired by the Pivot Phoenix downhill bike, maximizing the Firebird's rearward axle path to make quick work of square-edged bumps and softening the blow of repeated chunky hits. Greater control means greater speed, and it's certainly noticeable aboard the Firebird. Balancing the suspension with materials that can handle the terrain, the Firebird is crafted from a painstakingly precise mix of composite fibers and resin, then meticulously laid to create a frame that finds the happy medium of strength, stiffness, and weight. The chassis itself benefits from Pivot's hollow-core internal molding process for uniform, controlled wall thicknesses, and material distribution. This process virtually eliminates inconsistencies and resin pooling, increasing structural integrity while targeting areas for weight loss. In addition to hollow-core molding, Pivot implements size-specific design and ride tuning on their frames. In essence, the carbon lay-up, tube thicknesses, and tube shapes vary a bit between sizes in order to maintain a consistent ride quality across all frame sizes. Simply put, it's the best way to make a strong and lightweight carbon frame with an excellent ride feel. Pivot offers a variety of build kits to meet different price levels, ...