Take2 weeks ago
Berd wants vibration damping counted as a performance metric
Berd published a white paper on August 18, 2026 arguing that vibration damping and impact reduction should count as part of rolling resistance in performance modeling. The company wants smoothness treated as a hard number, not a subjective feel — and it has data to back the claim: independent testing found its spokes save 5 watts of rolling efficiency at 30 km/h on rough gravel compared to steel spokes. Co-founder Charlie Spanjers calls the damping effect from the material's viscoelastic polyethylene something that "took us a long time to quantify."
What this means
Berd is asking buyers and testers to evaluate wheels on a damping metric it is proposing itself, backed by watt measurements from independent testing rather than in-house claims alone.
The case rests on more than one number. Berd's white paper states the Sparrow50 Gold is 14% more aerodynamic than Berd's previous-generation Sparrow gravel wheel, so the white paper is pitching damping as a category to sit alongside aero and weight, not replace them. The energy transfer from the rim to the hub decays two to three times faster with Berd fiber spokes than with steel spokes, and Berd spokes show a 200% improvement in vibration damping compared with steel spokes. Spanjers describes the damping effect as an accidental benefit of the polyethylene's viscoelastic properties, one that "has taken us a long time to quantify."
Sources
Smoothness as a performance metric: Berd's case for why vibration is part of rolling resistanceBerd Sparrow50 Gold Carbon Wheels – Berd SpokesBerd's 1,298-Gram Gravel Wheelset Wants to Be the Fastest You Can BuyThe Berd Sparrow 50 Sets a New Gold Standard for Gravel Race WheelsReview: Berd PolyLight Fiber Spokes | The Loam Wolf
Analysed 5 sources, written and summarised with AI · How we work