UnUnU wrote:
Another question. Zipp 858 Disc Brake has max wide 23.7mm, why it is much lower than 454 (27.72mm) and 808 NSW (26.4mm)?
https://www.zipp.com/wheels/858-nsw-carbon-clincher-disc-brake/#
https://www.zipp.com/wheels/454-nsw-carbon-clincher-disc-brake/#
https://www.zipp.com/wheels/808-nsw-carbon-clincher-tubeless-disc-brake/# Ok just found this from aerogeeks.
"One more thing worth mentioning about the design… if you compare the 858 with an 808 NSW, you’ll quickly notice that the 858 is thinner—significantly so. An 808 is 26.4mm (front and back), while the 858 has a maximum width of 24.4mm at the front and 23.7mm for the rear wheel. According to Zipp, the reasoning behind the width difference as to reduce aerodynamic drag. In the absence of a crosswind, a narrower wheel is always going to be aerodynamically faster. One of the reasons aero rims have grown wider (an innovation that was first made by Zipp with their Firecrest wheels) is because, with a conventional rim, wider rims are less affected by crosswinds. With the Sawtooth rim design, Zipp has improved crosswind performance so much that they were able to go to a narrower rim and improve the aerodynamics even more. In short, they are able to get the best of both worlds—a wheel that is aerodynamically faster and more stable in a crosswind than a wide conventional rim."
If that is the case why 454 still has quite wide (27.72mm)? 454 also have good aerodynamic of a crosswind from Sawtooth design.