The 3D printed rotor guards tested, raced and won at the highest level of mountain biking

Disc brake covers have become a regular sight on the professional downhill MTB scene, and a UK-based company – G10 PRJCT – has brought the tech to the public at elite competition quality and reasonable prices, using 3D printing.

Gio Piras transferred years of motorcycle data engineering expertise across national supermoto and superbike championships, World Superbikes and MotoGP to the world of downhill mountain biking in 2025, when he saw the opportunity to apply his wealth of experience to a sport that was taking marginal, data-led inputs more and more seriously.

Linking up with leading pro team Santa Cruz Syndicate, the G10 PRJCT disc covers were tested and ridden to World Cup and World Championship titles by Jackson Goldstone.

Piras explained to voxelmatters.com his design, validation and production process, as well as the principles that drive G10 PRJCT’s current product line of specialized rotor guards.

“Production is currently carried out using a number of Bambu Lab H2-series printers. In terms of materials, we work with engineering-grade, fiber-reinforced polymers that are selected to perform well beyond the intended mountain bike operating scenarios,” Piras told voxelmatters.com.

“From a design standpoint, the key properties we prioritise are impact resistance, stiffness, thermal stability, and weight. The guards need to offer meaningful protection while remaining lightweight, and in racing conditions their primary function is to keep braking performance consistent by shielding the system from water, mud, and debris. The materials we use allow a good balance between these competing requirements without compromising durability.”

The design process is based on parametric and surface-driven CAD workflows. “This allows the development of organic geometries that closely follow modern suspension components,” explained Piras.

“Accurate fitment is critical, so the process starts from detailed 3D scan data of the fork and brake interfaces rather than relying on nominal dimensions. Earlier in development, iteration counts were higher, but as the workflow has matured we are often down to one or two design iterations before final validation.

“Regardless, every new product is physically checked for fitment and reviewed for potential improvements before release.”

Initial versions were tested during UCI Downhill World Cup racing last year, with wet and muddy conditions providing ideal validation scenarios. Rider feedback was positive on braking consistency, and more testing was done through the unforgiving British winter.

“Beyond riding and race testing, we have performed in-house destructive testing to validate impact resistance well beyond typical MTB use cases,” Piras told us. “A product is considered ready for sale only once the performance benefit is clear, fitment is precise, and the manufacturing process is fully dialled.

“Visual finish is also important – time is spent refining print parameters so the final part looks intentional and integrated on the bike rather than appearing as a prototype.”

Production of the covers is currently handled in small batches. This allows Piras to maintain a tight control over quality and availability, and the most popular configurations are kept in stock to avoid lead times for customers, who have ranged from dedicated private riders to racers and teams, with orders shipping worldwide.

The philosophy around G10 PRJCT focuses on elite level racing feedback that directly impacts everyday riders through the product. “The company is positioned first and foremost as a performance-driven engineering consultancy, with products acting as a tangible extension of that philosophy.”