Reynolds Blacklabel 309/289 XC 157mm Wheelset

The Reynolds Blacklabel 309/289 XC 157mm Wheelset sits at the top of Reynolds’ mountain bike wheel lineup — a carbon wheelset built explicitly for aggressive XC racing and high-performance trail riding, built with the same material technology the brand uses on its downhill wheels. The Blacklabel designation marks Reynolds’ premium tier, and the 309/289 XC earns that position with a combination of IDM carbon construction, Industry Nine Hydra hub internals, and a rim geometry that was engineered with intent rather than convention. The 157mm rear hub spacing makes this the Super Boost version, built for the growing number of modern mountain bikes that run the wider rear axle standard.

The rim profile on the 309/289 XC is the result of a deliberate design choice. Reynolds built the front and rear rims to different widths — 30mm internal on the front, 28mm internal on the rear — and paired both to a very shallow 21mm rim depth. The logic behind the mixed widths is straightforward: a wider front rim (30mm) adds steering precision and sidewall stiffness where you need it most for cornering traction and control. The slightly narrower rear (28mm) is matched to 28 spokes for an ideal balance of strength, compliance, and ride feel — enough stiffness to transfer power efficiently under hard pedaling, but not so rigid that it punishes you on rough terrain. Reducing the depth to 21mm across both wheels improves overall compliance and comfort, offsetting the potential stiffness penalty of running wider rims. The result is a wheelset that’s noticeably more planted on the trail than narrow, deep-profile alternatives.

Reynolds wraps both rims in MR5 (Mountain Rim 5) carbon construction with IDM — Impact Dispersing Matrix — a proprietary combination of high-quality carbon fiber and a unique resin engineered for superior impact resistance. IDM was originally developed for Reynolds’ downhill race wheels and carried directly into the 309/289 XC, giving these XC-weight rims a toughness that the weight number alone doesn’t suggest. The rims use a hookless bead and are tubeless-ready. The hub spec is equally considered: Reynolds’ proprietary CNC-machined shell houses Industry Nine Hydra internals, delivering 0.52° of engagement — effectively instant power pickup from the moment you begin a pedal stroke. On technical climbs where you need to find traction in a precise window, that engagement is the difference between clearing a move and dabbing a foot. Spokes are Sapim CX-Ray throughout — one of the lightest and most aerodynamically optimized spoke options available — in a 24-spoke front and 28-spoke rear lacing pattern, with external alloy nipples. The wheelset comes in at 1468g for the pair (689g front, 797g rear), and the rims carry a lifetime warranty.

Design Benefits

1. IDM Carbon — Downhill Toughness at XC Weight — Reynolds’ Impact Dispersing Matrix resin system was developed for World Cup downhill racing and brought directly into the 309/289 XC. The result is a rim that handles real trail abuse without the weight penalty you’d expect from that level of durability.
2. Mixed Rim Width for Front and Rear — The 30mm front / 28mm rear split is a deliberate design choice. More width up front improves cornering precision and tire sidewall support; the slightly narrower rear, paired with 28 spokes, delivers the right balance of stiffness and compliance where the power actually goes.
3. 21mm Rim Depth for Maximum Compliance — Reynolds intentionally kept the profile shallow to preserve the ride quality benefits of running wider rims. The low depth reduces rim stiffness in the vertical plane, translating to a more comfortable and confidence-inspiring ride on rough terrain.
4. Industry Nine Hydra Internals — 0.52° Engagement — The I9 Hydra ratchet system delivers essentially instant engagement, critical for technical XC and trail riding where power application timing matters. No dead spot, no delay, no searching for the bite point mid-climb.
5. Sapim CX-Ray Spokes Throughout — CX-Ray bladed spokes are among the lightest and stiffest available. The 24-spoke front keeps weight down and adds compliance; the 28-spoke rear adds the structural integrity needed to handle sustained power output and hard rear-wheel impacts.
6. Super Boost 157mm Rear Spacing — Built specifically for Super Boost rear dropouts, this wheelset is compatible with the broader range of modern full-suspension XC and trail bikes without requiring adapters or compromises.

Final Take

The Reynolds Blacklabel 309/289 XC 157mm Wheelset is built for riders who want a genuine performance upgrade — not just lighter wheels, but smarter ones. The IDM carbon construction, mixed-width rim profile, and Industry Nine Hydra hubs combine into a wheelset that performs at the top of the XC carbon wheel category while carrying the durability credentials to handle real trail conditions. If you’re running a Super Boost frame and want wheels that won’t hold you back, these are the ones.