Thomas Gerlach wrote:
Stumbled upon that last night. Hopefully he will get the GP 5000 TL data up soon as well. AeroCoach also published some data here and included the 5000 (23 & 25), TL (25), 4000, and TTHmmm...the aerocoach data shows the 23C versions of the GP5K vs. GP4K2 to be ~13% faster...which matches what Conti said...while the 25C GP5K is 20% faster than the 23C GP4K. Since all are tested at 90 psi, that makes sense. BTW, I calculate that if the 23C is tested at 90 psi, then the 25C tires should be inflated to 80 psi for an "apples to apples" comparison. The 18% better rolling for the 25C version comparison (GP5K vs. GP4K2) as reported by BRR seems a bit "off"...
Of course, the same is true with the BRR data in regards to pressure. His ranking is all with tires inflated to 120 psi regardless of size. To be fair, that's how my own testing is reported, but I'm about ready to "freeze" that data set and start reporting only with the tires inflated to the "Berto 15% Drop" calculated pressure based on actual measured width.
I have a hard time believing the GP5K would be faster rolling than a Turbo Cotton...
http://bikeblather.blogspot.com/