Slowman wrote:
dkennison wrote:
However, outdoor testing shows a whole lot of conditions (road surfaces) where pressures over 5 bar is faster. As the article points out most TT and triathlons are held on normal road surfaces as opposed to chipseal or cobbles.i'm not convinced of this. if you're talking about 28c and up. i don't think we've yet had that much testing on a 28c tire for TT applications. for Crr, that 28c tire in, for example, silca's calculator swells to 30mm when you put it on a hookless road wheel, because those wheels have such wide bead widths and silca specifies measured width. you have to get to a very smooth road before you exceed 5 bar on a 30mm measured wheel. and that's silca, which is going to yield higher pressures than what the manufacturers say their pro teams are using. i think this is one of those areas where we must agree to disagree pending some moment where those testing generate more agreement in their results.
I find it interesting that with NO DATA, we are claiming what is better/faster........and "I told you so".
"i don't think we've yet had that much testing on a 28c tire for TT applications", yet we're talking about a $3000 disc wheel for Tri and $2000 NSW wheels for Tri. Are we not ?
"pending some moment where those testing generate more agreement". If nobody shows their data, we will never get agreement. We have no data.
I have not seen any data on roads that resemble those used for TT and Tri. I have asked, nothing, nada.
I cannot release all my data. It belongs to the teams and the athletes and I know the team will not release it and I don't plan to ask the athletes. I can gladly talk about protocols to feel comfortable they make somewhat sense.
What I can release are "aggregated" results: very simply a 28mm tire (size on label), on a hookless rim, on a typical AGer, on a good bike path has an optimal tire pressure above 5 bar. This according to my results, which could be completely flawed. I don't pretend to have "the answer". But I do think what I am finding needs to be confirmed. I have also spoken to WT guys and they go "ya, that makes sense".
Speaking of WT experience, yesterday at breakfast a bunch of mechanics at the hotel were sharing their stories on hookless, tire recalls, disc brake specs, how they see things at 1000x the speed consumers do. That is worth an article all by itself.
I have quantified it for several riders, it's in single digit watts, but it's waaaaay more than the marginal aero benefit of a hookless interface.
The protocol could be optimized, how much you're leaving on the table should be better quantified.....there is definitely more work to do here, but it doesn''t seem anyone is interested on hard data.
We can do all kinds of mental gymnastics to get Silca to spit out a number below 5 bar. I never said Silca was right, I said my results are more like Silca than Zipp that chooses to ignore road conditions.
Dan, have Zipp send a wheel to Ronan. He is aware of the protocols, he has the equipment. Heck, send him the wheel and I am sure he'd come to Girona and we can find some interesting riders to test.
I did order myself a disk brake bike, just for hoots, to do more testing. There are things I've wanted to test as an AGer for a long time so I talked my Plasma 3 TT rim brake bike to share the garage. The tests are targeted to AGers wanting to quantify the BS level of some of the claims being made by manufacturers. Interesting enough, I was speaking to one manufacturer about something else, stumbled on my little project and he said "here, make these part of your experiment, no strings attached". That was cool.