You're not alone if you feel like 27. 5 inch wheels have swept through the mountain bike industry almost overnight. And, as a result, we've found that many brands are now completely reevaluating their approach to building trail bikes. In this spirit of throwing out old assumptions, SRAM started with a clean slate when it set to designing the ROAM 50 27. 5in Aluminum UST Wheel. Essentially it created that a wheel that's worthy of every part of the mountain, only at weight that's capable of dominating an XC race. In designing its new range of wheelsets, SRAM's engineers started with a blank slate. Accordingly, they focused on building wheels that provide durability, a responsive ride quality, and a light overall weight. The Taper Core construction of the aluminum ROAM rim is an illustration of this mission. Taper Core is the product of an extrusion process that allows SRAM to place more material where it's needed for durability. This results in a thinning of the remaining rim profile in order to optimize the balance of weight and strength. In fact, a cross section of the rim reveals that its main cavity is thinner on the sides than either the bead hook or the spoke bed. In other words, the sidewall thins gradually, providing a strong base for the bead hook. This way, the rim is more resistant to denting under hard impacts. The cross section of the ROAM 50's rim also reveals an asymmetrical shape that offsets the spoke bed. However, this isn't a mere novelty. Instead, it's actually key to building the ROAM wheels with zero dish, while simultaneously maintaining even spoke tension. Basically, with a traditional symmetrical rim, the spokes on the drive side must be shorter in order to keep the rim centered relative to the dropouts. Unfortunately, though, the discrepancy in spoke length puts greater tension on the drive side spokes than the non drive side spokes. As a result, this imbalance reduces the overall strength of the wheel. However, in the case of an offset ...