When deciding on this season's cyclocross tires, you need to evaluate what characteristics you actually need during competition. Resistance to punctures? Effective tread pattern? A compelling aesthetic? It's far-too-common to have to choose one and abandon the others. How about all of the above? The Challenge Grifo Cross Open tire carries multiple World Championships in its palmares for a reason -- it's one of the world's most well-rounded cyclocross tires.Grifo owes its success to a host of seemingly singular contributions, but ultimately, it all comes down the tread pattern. Challenge bestowed a pattern, that at first glance, appears low in profile -- and that's because it is. The pattern design doesn't require the extra weight of bulky, tall knobbies. Instead, the knob-shape provides ample grip in terrible conditions, while minimizing the associated rolling resistance. The highest point of the pattern lies in the middle of the tire, while moving outward, the knobbies gradually take on a svelte shape to provide traction in corners. However, the Grifo's tread pattern is intended to be mounted in either direction. Should you require heavy traction, say in hearty mud conditions, Challenge recommends that you mount the tire with the tread orientation facing backwards. For 'normal' race conditions, mount with the tread rolling forward. Regardless, you'll be rolling fast.For durability, the Grifo is constructed from a highly puncture-resistant and lightweight Super Poly casing. The bead of the tire uses an open tubular design. We know that it sounds like an oxymoron -- a clincher tubular. However, the benefits of Challenge open tubulars are astounding. They use the same hand-made construction techniques and materials as Challenge's tubulars. The only difference is that instead of being sewn, beads are actually formed by folding the casing around Aramid fibers. What's Aramid? Aramid is used for the tire beads for the same reason that it's used for bullet-proof vests -- its lightweight, compact strength. This fiber prevents rolling-off in corners, and adds to the cumulative strength of the tire.The Challenge Grifo Cross Open is only available as a 700c x 33mm open tubular tire and in the color Black/brown. Each tire weighs in around 340g without tubes.