Apparently so, according to the chart on page 4 of this PDF:
http://www.specialized.com/...ix_whitepaper_HI.pdf
I know they are probably playing games with 25mm versus 23mm tires, but really?
does that tire have a terrible reputation or something?
the gp4000s is sort of average, and yeah the wider roubaix would give it an ‘unfair advantage’ in this comparison.
I had the previous generation Roubaix Pro II on my Roubaix and I liked them. Bulletproof and I’d ride over everything. Only changed them out as I wore them off badly on the rollers.
The only other tire I’ve had on my bike is the Open Corsa Evo CX (23mm) and the rolling difference is significant.
I wouldn’t suspect that the newer Roubaix Tire is that much better than the old one, so it surprises me that it would be better than the GP4000s (which I though was at least a decently fast tire).
And if the tire is decently good, why don’t they equip the Roubaix with them? They come with either the Turbo Pro or a version of the Espoir.