Berd Spokes vs Steel: Ride Test & Wheel Building Deep Dive
Half of the gold medals in mountain biking at the 2024 Paris Olympics were won by athletes using bicycle spokes manufactured by Berd, a Minnesota-based company founded in 2015.
Berd Spokes began as a project in a Penn State University apartment, the brainchild of Charlie Spanjers, who was pursuing a PhD in chemical engineering, along with Brad Guertin and Kyle Olson. The initial goal was to improve cycling products through advancements in materials science. Their innovation centers on PolyLight™ spokes, constructed from Dyneema – an ultra-high molecular weight polyethylene fiber – and designed to be significantly lighter than traditional steel spokes.
The concept of using woven polymer spokes isn’t entirely new, with previous iterations appearing in products from companies like Tioga and Spinergy. However, Berd’s approach, and particularly the method of bonding a threaded stainless steel end to the Dyneema braid, proved successful. Spanjers described the initial breakthrough as accidental, stemming from a miscommunication between himself and Olson during the design process. This “finger trap” effect, where tension increases the grip between the fiber and the metal insert, became a key element of the spoke’s strength and durability.
For several years, Berd operated as a part-time venture, producing spokes in Brad Guertin’s basement. A turning point came in 2018 when the company won a business competition and secured grants that enabled a move to a facility in Minneapolis, and later Hopkins, Minnesota. This funding facilitated the development of an automated manufacturing process and the launch of the PolyLight spoke.
The company’s spokes are now available for around $9 USD each, a price point considerably higher than traditional steel spokes, which can cost around $4. Despite the cost, the weight savings – approximately two grams per spoke compared to a premium bladed steel spoke – and reported ride quality have attracted a growing following among cyclists and wheel builders. Wheelworks, a New Zealand-based wheel building business, has been a prominent advocate for Berd spokes since their early days.
Compatibility with existing wheel hubs initially presented a challenge. Fitting Berd spokes into hubs designed for traditional J-bend spokes requires a modification to enlarge the spoke hole from 2.6mm to 3mm, a process that can void the hub’s warranty and potentially introduce corrosion. Berd now offers protective inserts to mitigate corrosion risks. The company also offers hubs with a proprietary “hook flange” design, simplifying the installation process. Several hub manufacturers, including Onyx Racing Products, Erase Components, and Hope, now offer hubs compatible with Berd’s hook flange system.
Building wheels with Berd spokes also requires a different approach than traditional methods. The Dyneema material stretches under tension, necessitating a multi-stage build process where the wheel is repeatedly stressed and allowed to settle over several days. Berd and Wheelworks have developed specialized tooling, including pneumatic presses and digital truing tools, to streamline this process. Berd CEO Charlie Spanjers stated the company now stress-relieves all wheels built in-house for three cycles with 635 lbs of force on each side.
Berd currently offers the original PolyLight spoke, as well as the PolyLightX, a more robust version designed for e-bikes and gravity mountain biking. The company also provides a rebuild service, allowing customers to send in existing wheels for spoke replacement.