@Ronan_Mc_Laughlin On Geek Warning #178, 17 Oct, you mentioned something to the effect that the so-called rule of 105 wasn’t held in high regard by aerodynamicists. Can you direct me to your podcast or article where you discussed this? Cheers.
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I believe it was the episode with Xavier Disley from Aerocoach from November 2024
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Perhaps I misheard, but I thought that it was more that the rule of 105 relevant with narrower tires and v shaped rims, but is outdated at this point.
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I think there was an interview (possibly around the time of the TDU, but I could be wrong on that) with JP Ballard, and I believe he said testing at Swiss Side didn’t show any particular benefits to the rule of 105.
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yeah, the two that spring to mind are an episode with Xavier Disley, (I think this one Performance Process: Aero secrets with the Aerocoach, Xavier Disley , maybe this one Performance Process: Aero claims exposed & how to spot marketing spin) and an episode with JP Ballard from the three part series I did with him in January 2024. Podcast: Aero myths and the best bang-for-buck gains with Swiss Side's JP Ballard
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Thanks everyone. FYI, In episode 4 Aero claims exposed and how to spot marketing spin with Xavier Disley at 40:09, in response to Ronan’s question about the rule of 105, Xavier calls it “absolute garbage” and says “it only was relevant for rims that were a shape we’ve long gone passed…” In episode 53 Is lower slower? Aero part 2 with JP Ballard at 52:50, JP says “I can categorically say isn’t true.” This confirms exchanges I had with engineers and product managers at ENVE, Bontrager, Campagnolo and Zipp in 2022 who said they didn’t follow this or any other rim to tire width ratio to guide their wheelset development when optimizing aero performance. Cheers.