SRAM is suing Princeton Carbon Works for infringing a patent relating to an undulating rim design that is said to reduce aerodynamic drag and side force, which is a factor when riding in crosswinds.
SRAM says that the wavy rim shape on Princeton's 6560 carbon road wheel infringes its patent for the rim design that features on its Zipp 454 Carbon NSW wheels.
“SRAM's wheels rely on two patents from inventor Dimitris Katsanis. The first patent was issued in 2017 and a related patent was issued in 2020. Katsanis assigned both to Metron IP Limited, a Nottingham, UK, company, who in turn assigned them to SRAM. It's not clear when the patent was assigned to SRAM,” Bicycle Retailer reports.
Katsanis is best known in the cycling world for designing track bikes used by Team GB.
SRAM’s patented rim shape is in part inspired by a humpback whale, with the "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.
Princeton Carbon Works is a relatively young US performance wheel brand that arrived on the scene in 2018, conceived by a group of engineering graduates from Princeton University.
Princeton’s Wake pattern is said to have taken four years of development, and what you are left with is a rim that contains 24 sinusoidal oscillations, giving a depth that varies from 60mm to 65mm.
"Advanced aerospace engineering facilitates better speed through the breakthrough of dynamic cross-section variability – WAKE – which yields lower drag and reduced effects of vortex shedding," says Princeton.
Stu Kerton recently reviewed Princeton’s Wake 6570 Disc Tune wheelset and his full review can be found here.
The depth of the Princeton rim and the Zipp rim each vary, but the Princeton undulations appear symmetrical while the shape of Zipp’s is more like a sawtooth.
SRAM complains that Princeton was aware of the SRAM patent and continued to market its wheels. SRAM is asking for tripled damages for willful infringement and for Princeton to be ordered to deliver up for destruction any remaining inventory, according to Bicycle Retailer.
As I posted earlier seat belts are not mandatory you can buy an old sports car that can do well over 100mph that requires no seatbelts or roll bar...
But what if it's crunchy peanut butter and the dog decides to bite?????
Much of your review might as well be writtten about your own review: I give it 6/10, and no, your style doesn't appeal to me.
Nissan Micra seized for parking on same Sheffield pavement twice in six months...
As per other comments, it's all out of sync with model years isn't it at the moment. Some bikes are still full price but still lots are discounted...
Highway Code Rule 59 is unusual...
JRA Monitors are 25mm deep - how's that 'deep section'?
not least because it's a special edition - chromed mirrors and black wheels. There can only be a few hundred of those at most.
She could buy a bike manufacturer and have the firm build her a series of different bikes to suit her mood.
Wot no Furry of the Mountain?