From a
Competitive Cyclist review of the GP4000S:
"We were staring at the tread and riding and staring, wondering how this tread was supposed to grip better than a traditional "slick" tread. In our riding, we didn't notice any better or worse grip. So we asked. We were told that the little side tread shapes are for show. Slicks grab better and bikes don't hydroplane, but there are people who just refuse to believe that slicks are better. So Continental puts a little side pattern on to make a good show to allay the concerns of the doubters who want tread."
From this it appears that tread is just a marketing "gimick".
