rmba wrote:
Quote:
basically was tied with the 24c Turbo Cotton (.0028 vs .0029 respectively), but actually measured slightly wider than the TC (24.6mm vs 24.25mm, mounted on a Mavic Open Pro at 120 psi), so make of that what you will...So you mean that the CRR was pretty well a wash but the GPTT 23 likely had increased CdA?
Any comment on old TC (~1000km max) vs new GP TT?
I think that is what Tom A meant for the rolling resistance yes.
For the CdA, wider does not always mean less aero as it is rim dependant... though as a general rule it makes sense but it can be wrong (like GP 4000S II 700x25 which is quite ok on modern rims).
The only aero test I've seen for GP TT is from Swiss Side on their Hadron 625 wheel (see below) and show poor aero for the TT after 7.5° of yaw... bad news. Good news is under 5° it seems to be on par of slightly better than GP4000S 700x23...
Now if we consider (and I'm not saying this statement is true) that on modern rims a tyre that is aero on one is often aero on another (that's the case for GP4000S 700x23, GP Attack 700x22 and GP Supersonic 70x23 for which we've seen results on more than one rim in more than one wind tunnel) then we can expect GP TT to be quite good at low yaws on most modern rims. And we also know that Turbo Cotton 700x24 is not so good at low yaws since it's also been tested on more than one modern rim.
So GP TT rolls slightly better, is slightly better at low yaws aerodynamically and in my experience is quite reliable... this is why it is my tire of choice for most races though I would probably now consider Force 700x24 (since the rims I use are wide enough for it)) on a very windy day...
