Vittoria Open Corsa EVO SL

After, literally, millions of miles of race testing, Vittoria has developed its new EVO line of Open Corsa tires. And while the each of these cotton-cased tires plays a specific role, the EVO SL differentiates itself from the SX and SC tires in the Corsa line by featuring a slick tread pattern. So, with an emphasis placed on low rolling-resistance over traction, the SL is particularly adaptable to racing and time trials. Or, more simply put, the SL is solely built for speed. Now, if you're unfamiliar with how the Italians operate, we'll breakdown the title for you. 'Open' is the Italian terminology for clincher, as in the clincher-version of Vittoria's Corsa SL tubular tire. Meanwhile, 'Corsa' translates directly to 'race,' as in, this is a race-designated tire. Put the two together, and add in the evolution designation of 'EVO,' and you have a next-generation tire that's designed for speed. And while we understand that a name is simply a name, the Open Corsa line's results speak for themselves. Simply put, this line boasts more race wins than any other tire in history. And now that we have your attention, let's dig into the SL's construction. Vittoria gave this tire a 320TPI casing composition, meaning that the casing of the tire (what the rubber is applied to) is comprised of 320 threads per inch. And if you're wondering why there are 'threads,' this is because the EVO SL is a cotton tire. But, don't think that this decreases durability. In fact, Vittoria used a corespun, or 'polycore,' technique for the casing's construction. Essentially, this means that the casing fibers are made by twisting staple cotton fibers around a central filament core, creating one yarn from multiple fibers. As a result, the material is between 40 and 50% stronger than typically spun materials, while retaining a similar, if not lower, overall weight. Additionally, the 320TPI cotton casing provides the ideal stiffness-to-weight ratio for the SL. By this, we mean that the tire's weigh...