There is some subjective and rational aspect on the ranking.NordicSal wrote: ↑Tue Jan 24, 2023 9:53 pmWould be really interesting if someone could write down a few points about how to read this info.
Points answering questions not limited to but like these:
What is good/bad stiffness and why?
What is good/bad aero and why?
So much knowledge in here that's not shared because a lot of you are already in the know.
Aero: ideally the lower the better, to be taken with a pinch of salt,
- those values are normalized from measures taken from -20 to 20 deg yaw angle (apparent wind angle) with a weighting (on top of my head you spend 90% of the time in less than 7deg yaw, so low yaw angle have more weight than large ones).
- Sometimes Tour publish sensitivity to lateral wind (how much instability is transmitted to the direction), if you get the magazin the details are there.
- Another limiting factor is the tire-impact, see below.
Stiffness: Stiffness impacts few rational and "feeling" aspect
- rational the power: long story short, out of the saddle you go faster. You have better pedal efficiency, out of your power, more is used to move you forward and in accelerations you have higher power-peaks.
- feelings, more difficult to quantify (better steering precision, more reactive bike).
--> Below 40N/mm I consider it quite too flexible (flagged in red) and the ideal being above 50N/mm (55 will flag green).
- One point I may illustrate later, wheels being assymetric (either the disc or the disc and the cassette) they are never as stiff in both direction but while some have few % difference, some display large variations.
Tour test with a GP4k in 25mm (that measures 27mm wide on a narrow rim -17c?- so likely close to 29 on 21 inner rim) so it benefits to wide rims. From the table published above I would say that Zipp 303, Bontrager and Cadex benefit from this tire-size when the Zipp 454, Cosmic Ultimate, Cadex 36 and LW would save 1-2 watts with an 25-27mm real width tire.Mr.Gib wrote: ↑Sat Jan 28, 2023 11:36 pmJust looking at that data, I am pleased to see that wider doesn't seem to be slower. All the 30mm and wider rims of adequate depth performed well. I always wondered what price I was paying for running 32mm wide rims. Apparently none according to this testing. However, assuming equal tire/rim aero optimization, a 28mm wide rim must be faster than a 32mm wide rim? Perhaps the differences are so small that they cannot be measured.