Yeah...it's been awhile. Lots of things happening in the last year.
Anyway, It's time to get caught up. Although this tire rolling resistance data was published last spring after I did a collaboration with Jon and Chris of Flo Cycling (see report here), I have been remiss in adding it to the spreadsheet linked to on the right side of this blog. These are tires I roller tested for the Flo tire aero study, models of which I had not already tested. Here are the additions from that testing:
Continental GP4000SII 25C = .0031, 28W for pair @ 40kph
Continental GP Attack 22C = .0033, 31W for pair @ 40kph
Continental GP4000SII 23C = .0034, 31W for pair @ 40kph
Schwalbe One Tubeless 25C = .0037, 34W for pair @ 40kph
Schwalbe One Tubeless 23C = .0041, 38W for pair @ 40kph
Felt TTR1 23C = .0048, 45W for pair @ 40kph
Continental Gatorskin 25C = .0048, 45W for pair @ 40kph
Continental Gatorskin 23C = .0052, 48W for pair @ 40kph
The interesting points in there for me are the confirmation that the GP4000SII rolls the same as the previous GP4000S, plus how poorly the Gatorskin models roll at 17-20W worse than the GP4000SII for a pair at 40kph. Wow.
Additionally, in August of 2016, I finally got around to testing a pair of tires that Eric Reid had sent me. One was a brand new model of the Continental Force tire (I had only previously tested a lightly used one) and also a Continental GP TT tire. The latter is a tire that hasn't had much test data on it, so it's something I really wanted to see. Here are those results:
Continental GP Force 24C = .0030, 27W for pair @ 40kph
Continental GP TT 23C = .0028, 26W for pair @ 40kph
That result for the GP TT makes it the new "top dog" for brand new tires I've roller tested. One caveat on that tire though...it measures much larger (24.6mm) than it's rated 23C on my narrow Mavic Open Pro rim, or nearly 2mm wider than a Continental SuperSonic 23C (22.8mm) on the same rim, and is only .0001 lower Crr (~1W difference at 40kph for a pair, or what I consider "tied").
Finally, in October of last year, I roller tested a couple of other tires. One was a newer version of the Continental 20C SuperSonic. I was interested to see if, like some of Conti's other tires, it had gotten any faster since I had last tested that model in 2012. It did. Here are the results:
Continental SuperSonic 20C = .0030, 28W for pair @ 40kph
That's a fairly significant change from the previous measurement of .0034 for that tire, and corresponds to an improvement of ~3W @ 40kph for a pair, and is just as fast as many tires of MUCH greater width.
The other tire I tested in October was the Specialized S-Works Turbo Tubeless 26C model. This tire was interesting to me because it had been getting some "buzz" about how it was a super-fast tubeless tire (most aren't up to this point).
In this case, I tested it both with a latex tube inside, and then also set up tubeless, with Orange Seal sealant inside (~20ml). Both tests measured nearly exactly the same (within less than .0001 Crr) with the result being:
Specialized S-Works Turbo Tubeless 26C = .0032, 30W for pair @ 40kph
Although that's relatively fast for a tubeless tire, it's not the world-beater it had been hyped to be...especially considering that it's mounted width on my Hed Jet+ wheel for that testing was nearly 30mm!
Anyway...good to be back at it, and I've got some other fun stuff (not so much tire related, hopefully) to be sharing with all of you shortly. Again, all of these updated entries are in the spreadsheet link in the upper right of this page.
edit 23Jan2017: After roller testing a newer version of the Continental SuperSonic in 2016 as described above, I decided to use the newer value in calculating the total power for the H3/Conti 20C SS combination in the chart shown in my last "Win Tunnel Playtime" post. With those changes, the chart looks as follows, and it appears the old H3 has some pretty good speed in it still with that tire: