Reynolds Blacklabel 309/289R Boost Wheelset

The Reynolds Blacklabel 309/289R Boost Wheelset is a limited edition XC carbon wheelset that pairs Reynolds’ proven rim construction with turquoise-anodized Ringlé Super Bubba X hubs — a collaboration between two brands with deep mountain bike roots. The 309/289R name reflects the most distinctive feature of this wheelset: front and rear specific rims, each engineered for the unique demands of its position on the bike. The front 309 rim runs approximately 30mm internally; the rear 289R runs 28mm. That difference is intentional, not incidental, and it shapes how the wheels perform at both ends.

Reynolds designed the wider front rim to support the modern trend toward larger-volume front tires, giving the bead more surface area to seat against and allowing the tire to maintain its intended profile under cornering loads. The narrower rear rim keeps weight down where it matters most for acceleration and climbing, and suits the slightly narrower rear tires most XC riders run. Both rims are built with Reynolds’ IDM (Impact Dispersing Matrix) — the same high-quality carbon fiber and impact-dispersing resin combination found in their gravity wheels — combined with MR5 (Mountain Rim 5) construction, which engineers each structural zone of the rim individually to balance strength, weight, and compliance. The result is a rim that holds up to aggressive XC riding while remaining light enough for race use. Claimed weight for the set is 1,540g, and both wheels are tubeless-ready.

The hub story is what makes this a limited edition. Ringlé’s Super Bubba X is a fully CNC-machined hub with turquoise anodizing that references the original Super Bubba hubs of the 1990s — an era when Ringlé’s components were fixtures on the most capable XC bikes of the day. The Super Bubba X uses a drop-in ratchet ring design with 4° of engagement, delivering immediate power delivery for trail riding and technical XC. Straight pull Sapim CX-Ray spokes — among the strongest and lightest straight-pull spokes available — are laced with external alloy nipples, using 24 up front and 28 in the rear, a distribution that balances the stiffness requirements of each wheel’s role.

Design Benefits

1. Front and Rear Specific Rim Widths: The 30mm internal front and 28mm internal rear aren’t simply trimmed from the same mold. Reynolds designed each rim profile for the specific performance requirements of its wheel position — maximizing front tire support for grip and cornering while keeping rear weight and profile optimized for acceleration and climbing efficiency.
2. IDM + MR5 Construction: Impact Dispersing Matrix carbon combines high-quality fibers with a specialized resin tuned for impact absorption without sacrificing structural performance. MR5 rim architecture treats each zone of the rim individually — spoke bed, bead wall, and center channel — balancing strength, compliance, and weight at every point. These are the same technologies Reynolds uses in their gravity wheels, applied to an XC-weight package.
3. Ringlé Super Bubba X Hubs: The turquoise anodizing is a nod to Ringlé’s heritage, but the Super Bubba X is a performance-first hub. CNC-machined, with a drop-in ratchet ring for easy maintenance and 4° of engagement for crisp power delivery on technical terrain and out-of-the-saddle efforts.
4. Sapim CX-Ray Straight Pull Spokes: CX-Ray spokes are the choice of high-end wheel builders for their combination of tensile strength and minimal weight. The straight-pull configuration eliminates the stress concentration at the spoke elbow that can lead to fatigue over time. 24 up front, 28 in the rear, with external alloy nipples for easy field tensioning.
5. Lifetime Rim Warranty: Reynolds backs the structural integrity of every Blacklabel rim with a lifetime guarantee to the original owner — a statement of confidence that holds up to the wheelset’s race and trail use case.

Final Take

The Reynolds Blacklabel 309/289R Boost Wheelset is a well-considered XC carbon wheelset that earns its price through specific engineering, not spec sheet padding. The front/rear rim differentiation reflects how XC riders actually use their wheels. IDM and MR5 construction bring Reynolds’ durability reputation to a lightweight XC platform. And the Ringlé Super Bubba X hubs make this the version worth having — turquoise anodizing, immediate engagement, and the kind of finish quality that holds up to close inspection. Available while supplies last.