I take the matter of purchasing tires as personal as my research and purchase of a saddle. Tires are the only aspect of the bike that comes in direct contact with the ground (hopefully) and this becomes alarmingly apparent when hitting 50mph down Palomar or when you are suddenly caught out in a downpour. You want a tire that you can trust in all situations, no flats, no blowouts, no slide-outs. As with saddles, tires are also important in terms of comfort and overall ride quality.
A couple years back it seemed that the go-to tire was the Michelin Pro Race series. They had been tested and proven among amateur, pro, and recreational riders and could be found at a great price at just about any shop. Recently the tides have changed as the Continental Grand Prix 4000S series has quickly become a favorite.
At 460g for a pair they prove light enough for the hills yet they are able to maintain strength for rough roads. The 4000 S with added “Black Chili Compound” claims 26% reduced rolling resistance and 30% increase in grip over the 4000 line with no Black Chili.
No, Continental is not adding cooking spices to their tires. Black Chili Compound is composed of tiny black carbon particles incorporated into the rubber solution of the tire. With these particles being more flexible they are able to better mold to the road surface for better grip during cornering and also aid in rolling resistance.
Continental GP 4000 S tires are definitely not the cheapest of what Continental has to offer, but with tires cheap is the last thing you want. I have to admit to some personal, maybe accidental, testing of these tires through glass and gravel and they have yet to fail me.