Berd has made a name for itself with its unique PolyLight spokes and lightweight, high-end wheelsets. Today, the brand introduces the new Sparrow50 Gold gravel wheelset, which it claims is “the lightest production 50 mm gravel wheelset on the planet.” With 30 mm-wide, 50 mm-deep carbon rims and Berd’s Polylight vibration-damping spokes, they also state that the Sparrow50 Gold is the “fastest and smoothest gravel wheelset available today.”
That’s a bold claim, but the self-proclaimed bike nerds at Berd (Bike + Nerd = Berd) are backing it up with science, of all things. Not only are they launching the Sparrow50 Gold wheels today, but they’re also laying out the engineering framework in their white paper, including the equations, physics, and field data behind their claims. Along with that, Berd is also launching a free “finish time calculator” so riders can compare the effect of wheels and tire widths on their ride times.
Sparrow50 Gold Details
The Sparrow50 Gold wheels are made with “super aerodynamic” 50 mm deep carbon fiber rims in 700c (29”) or 32” diameters. The rims have a 30mm internal width, a hooked bead, and a 4mm-wide bead top to reduce the chances of pinch flats. The 30 mm width is compatible with tires from 40 mm to 60 mm wide, and has been “tunnel-optimized at 45-55 mm” with Schwlabe G-One RS Pro tires. According to Berd, the new Sparrow50 rim and wheelset is 14.3% more aerodynamic than the standard Sparrow in wind tunnel testing.
Of the tires tested, Berd says that the 45mm Schwalbe G-One RS Pro had the lowest drag and was the fastest on smooth gravel. However, through their finish time modeling, they say that 55mm tires can be faster on rough gravel, despite having slightly worse aerodynamics.
Talon ESL-R Hubs
At the center of the Sparrow50 Gold wheels are Berd’s Talon ESL-R hubs, which the brand calls its “fastest gravel hub yet.” These hubs use Berd’s patented hook flange design with Equal Spoke Length (ESL) technology. By varying the hook flange widths, every spoke, front and rear, is the same length to keep wheel building and maintenance simple.
The Talon ESL-R rear hub uses a dual-sprung 36-tooth ratchet for quick engagement and a Tri-Coat aluminum freehub, which is available in SRAM XDR, Shimano Microspline or HG, and Campagnolo N3W. The front hub is convertible between 12 and 15 mm axles with tool-free end caps, and the wheels are available in standard gravel (12 x 100 mm / 12 x 142 mm) and Boost (12 x 110 mm / 12 x 148 mm) spacing with a centerlock brake rotor interface.
Berd Spokes
Tying those aerodynamic rims and hubs together are Berd’s unique Polylight spokes. Berd tells us that its spokes have “earned two Olympic Gold Medals and more than 50 UCI World Cup cross country podiums over the last two seasons, making them the winningest XC mountain bike spokes in the world.” According to the brand, the viscoelastic spokes damp vibration, reducing feedback and fatigue, but also smoothing the ride and enhancing efficiency.
In fact, along with the more easily measurable variables of aerodynamic drag and mass, they believe the Berd Spokes’ dissipation of high-frequency vibration contributes to lower rolling resistance compared to metal spokes. You can learn more about it in Berd’s white paper, but they claim that independent third-party testing by John Karrasch showed a 5-watt savings at 30 km/h from vibration damping alone.
Berd is based in Hopkins, MN, where each Sparrow50 Gold wheelset is hand-laced, then precision trued by TRUDI, the brand’s automated wheel truing system.
Weight
According to Berd, the 1,298-gram weight of the 700c (29”) wheelset is the “lightest production 50 mm gravel wheelset on the market.” That weight goes up to 1,541 grams for the 32” size.
Warranty
The Berd Sparrow50 Gold wheels are covered by a lifetime warranty against manufacturing defects. Additionally, they are backed with lifetime crash replacement — “if you damage your rim while riding, you’re covered under our free crash replacement program.”
White Paper and Finish Time Calculator
Are you a bike nerd interested in all of the physics, equations, and data behind Berd’s spokes and performance claims of the new Sparrow50 Gold wheels? Berd’s white paper lays it all out for you to see. Check it out here.
Berd’s finish time calculator is also live on the Sparrow50 page of the Berd website, down near the bottom of the page. According to Berd, “The model accounts for aerodynamic drag, rolling resistance, and the vibration-induced losses that Berd spokes uniquely reduce. Results are intended for comparative purposes only — the calculator uses simplified assumptions for rider aerodynamics and does not account for elevation, drafting, or variable pacing.”
Sparrow50 Gold Specs
- Wheelset Weight (w/out rim tape or valves):
- 700c, 29”: 1,298 g (600 g front, 698 g rear)
- 32”: 1,541 g (718 g front, 823 g rear)
- Internal Rim width: 30 mm
- External Rim Width: 38 mm
- Rim Depth: 50 mm
- Rim Material: Carbon Fiber
- Wheel Size: 700C (29”) or 32”
- Hubs: Berd Talon ESL-R
- Front Spacing: 12 x 100 mm, or 12 x 110 mm (convertible to 15 mm)
- Rear Spacing: 12 x 142mm, or 12 x 148 mm
- Freehub: SRAM XDR, Shimano Microspline, Shimano HG, or Campagnolo N3W
- Brake Rotor Interface: Centerlock
- Spokes: 24 Berd PolyLight spokes
- Nipples: Sapim Aluminum Double Square Lock
- Tire Compatibility: 40 to 60 mm (1.50” to 2.35”), tubeless-ready
- Max Tire Pressure: 60 psi (4.14 bar)
- Weight Limit: 280 lbs / 127 kg
- Warranty: Limited Lifetime Warranty and Free Crash Replacement
Berd Sparrow50 Gold: Pricing and Availability
If you’re interested in the “fastest and smoothest” gravel wheels available today, it’ll cost you. The 700c / 29” Sparrow50 Gold wheels retail for $2,395, and the 32” version goes for $2,495.
The 700c wheels are in stock and ready to ship, and the first 50 orders get a set of Schwalbe G-One RS Pro 45mm tires. The 32” wheels are available for preorder with an estimated ship date of 9/21/2026. Head to the Berd website to learn more or pick up a set.
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