Hexsense wrote:Interesting. I recall that you said for 50.7mm best aero with U-shaped would be 30mm+ that's why we get the 507's V-like shape. So the deeper it get, the more wide it require to make it best aero possible?
In that case, the limit would be around 32mm for disc brake (like Enve 4.5 AR disc) and around 29.9mm (like Roval CLX64) for rim brake right?
Also, 25mm tire means literally 25mm measured width? or the tire labelled 25c which is usually 28-29mm wide?
Yes, that is why I did not go with a "U" shape with the 507 as it cannot do much due to the 25mm wide tire as measured, not as it says on the tire casing. 507 thus has good trailing edge aerodynamics and very good handling characteristics.
Regarding the depth, no...the reason for the rim width is the shape of the tire which is aerodynamically very bad. The extra rim depth only makes it a bit less terrible. Any open (ie. not solid disc) rim would need to be about 45mm wide in order for the aerodynamics to be optimal with tires inflated to 25mm wide. If you then go to 28mm tires, you'd basically need an airplane wing to make it work.
There are no aerodynamically optimal rims available (besides solid discs, they are cool). We are all limited by the real life constraints: available space and acceptable weight. Lastly, open wheel, unfaired vehicles are beyond salvation when it comes to aerodynamics, so all we can do is focus on minimising the damage...
When the market moves back to narrow tires (everyone realizes that crr is irrelevant compared to aerodynamic drag, and comfort is subjective) we can do a better job
V.