Big wheels roll fast, especially on modern iterations of a 29-inch trail bike. But, a bigger wheel also amounts to more required leverage and more weight. For these reasons, SRAM focused on strength and weight loss when designing the ROAM 50 29in Aluminum UST Wheel. Not surprisingly, the ROAM makes good on those intentions, and delivers a wheels that holds up to the riding styles of modern trail riders. It features a wide, asymmetrical aluminum rim and hubs that are easily serviceable by home mechanics. So, you get the strength that you need, in a package that's light enough to warrant a spot on a XC race bike.
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 RAIL 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 RAIL 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 rim design, like the RAIL, the spoke bed aligns with the hub shell. This keeps both the spoke tension and spoke length equal on both sides, while the shape of the rim centers the tire relative to the dropouts. This way, the RAIL wheels maintain correct spacing and reap the benefits of even spoke tension. And remarkably, this is achieved with identical spoke lengths on both sides of the hub, at both the front and rear. This not only adds strength, but it also means that one replacement spoke is able to be used on the on any side of either the front or rear wheel.
Building a balanced wheel is important, but it doesn't mean much if your tire doesn't have a stable platform to rest on. SRAM's Wide Angle rim shape addresses this concern with a 21mm internal width that matches up with today's wider tires. So, your tires will remain planted through hard turns, not roll off of the rim.
At the center of the RAIL 50 wheels, you'll find user-friendly hubs. A straight-pull spoke design is employed, as opposed to a traditional J-bend spoke. As a result, stiffness was improved, while also adding the benefit of making on-the-fly spoke replacements a bit easier. The axles use push-on end caps at front and rear, meaning that fitting these wheels to nearly any mountain bike axle standard will be a breeze. The freehub is available in both a standard 9/10-speed configuration, as well as SRAM's XD freehub body. And regardless of the version, both freehub designs run on DT Swiss's Star Ratchet system. Not only has the Star Ratchet system earned a reputation for light weight and durability, but its design enables home mechanics to overhaul the rear hub without any proprietary tools.
The SRAM ROAM 50 29in Aluminum UST Wheel is sold individually and in a 29-inch wheel compatibility. Please note that the rear wheel is available with either a Shimano/SRAM 9/10-speed freehub body or a SRAM XX1-compatible free hub body.
- TaperCore construction
- Asymmetrical spoke bed
- 21mm internal rim width
- Straight-pull spokes
- Push-on end caps
- 9/10 or XX1 11-Speed
View more 29" Mountain Bike Wheels - Tubeless
Reviews & Community
I ride a 2014 Cannondale Scalpel 4 (no lefty). The front hub on this is a 20mm which is hard to find. Is this wheel compatible with both the 20mm and 15mm (for a future upgrade)?
- Familiarity: I've used it several times
I set these up on my Yeti sb95 carbon, and so far have been loving them. For a non carbon wheel, they are pretty lightweight, and have kept my bike weight down to 26lbs, which is pretty awesome for a trail bike 29'er.
These wheels are super easy to mount a tubeless tire on, and also switch between axle sizes really easily by just popping out one part of the hub with your hand (no tools) and adding one of the other sizes that are included with the set.