Princeton Carbon Works says it feels “validated” after SRAM dropped its appeal against a court’s ruling that the performance wheel brand’s aero design does not infringe the component giant’s patents, finally bringing an end to the long-running dispute.
The five-year legal battle between the two companies began in 2021 when SRAM filed a complaint accusing some of Princeton’s models of infringing on patents for the undulating rim shape, said to reduce aerodynamic drag and side force, used on SRAM’s Zipp 454 Carbon NSW wheels.
In February 2023, a jury in Florida returned a verdict that Princeton had not infringed either of the two patents SRAM had accused the company, established in 2018 by a group of engineering graduates from Princeton University, of violating.
SRAM then appealed the ruling, but road.cc understands that the Chicago-based components giant informed Princeton in recent weeks that it had dropped its appeal, a decision confirmed to us by Princeton on Wednesday.
“We are obviously happy this lawsuit is behind us and feel validated with the result,” a spokesperson for the company told road.cc.
“We look forward to continued innovation and offering the highest performance wheels to our world class athletes and customers.”
The wheels at the centre of the patent dispute – the Zipp 454 Carbon NSWs – rely on two patents from inventor Dimitris Katsanis, best known in the cycling world for designing track bikes used by Team GB.
SRAM’s patented rim shape is partly inspired by a humpback whale, with the article ‘Hydrodynamic Design of the Humpback Whale Flipper’, published in the Journal of Morphology in 1995, cited in the patent.
The sawtooth design came from the irregular shape of the leading edge of humpback whale pectoral fins.
On the other hand, Princeton argued the Wake 6560 design came as the result of four years of development by Princeton Carbon Works and contains 24 sinusoidal oscillations, giving a depth that varies from 60mm to 65mm.
As we noted in our original article on the patent dispute back in 2021, the depth of the Princeton rim and the Zipp rim each vary, but the Princeton undulations appear symmetrical while the shape of the Zipp is more like a sawtooth.
In its complaint from March 2021, SRAM alleged that Princeton was aware of the patent and continued to market its wheels. SRAM asked for tripled damages for wilful infringement and for Princeton to be ordered to deliver any remaining inventory up for destruction.
However, in the end, the jury ruled against the Chicago-based company, a decision that now appears certain to stick after five long years.
SRAM declined to comment when approached by road.cc.
