I've searched but I don't see any real comparisons between the two. They are comparably priced, one comes in colors and multiple sizes and the other comes only in black and 23mm. If you compare black to black, both have the "black chili" compound and Vectran fabric. The 4000S is marginally lighter. Both claim reduced rolling resistance, increased grip and increased tread life.

Does anyone have direct experience with both? Is the difference worth commenting on or worrying about, or should I go with the one that looks better?

Thanks.

-soma5

The black ones are the same except for the graphics.
The colored ones don't have black chilli, which is a big improvement over the old compound

I've run the GP4000s for a while and get about 3500 miles out of them. I bought a pair of the GP4000S's last year, hung them in the garage for the winter, and then started riding them at the end of March. I don't feel a noticeable difference between the two tires but my rear tire only has one minor nick on it after 500 miles. By this distance, I would usually see a few nicks or cuts on the GP4000's that I fix with superglue gel but nothing on the S so far. So, I do not know if the minimal wear/damage is caused by the new rubber compound or the aging in the garage but I like the S tires better than the standard GP so far.

What is this "chilli" compound? What does it do, how does it work? I thought it was just marketing BS. I use red GP4000s anyway but if there was a measurable difference I would change back to black.

Here you go.