Vittoria Corsa EVO CX Clincher Tire
The Vittoria Corsa EVO CX Clincher is what we've been trained to see as a high-performance tire. It has a round profile, a file tread down the middle and diagonal sipes on the shoulders, and a heat transfer label embedded on the edge of the tread. Everything about it says 'handmade tubular.' It's not as modern as a Michelin or Schwalbe, or as industrial as a Continental: the Vittoria embodies the traditional tubular aesthetic.
Tests indicate it yields performance on par with its image. The Bike Tech Review tire testing guru, Al Morrison, has tested this tire and found it among the top performers. It isn't as fast at the winning Vittoria Pista EVO CS tubular, but that's a track tire, and it ranks behind the Vittoria EVO Chrono tubular and Vittoria Ultra Speed clincher, but ahead of the Vittoria Corsa EVO CX Tubular.
An 'open tubular,' for those not familiar with the concept, is a clincher tire built with a tubular tire casing. It's true that there are cheap tubulars and that cheap clinchers could come out of the same process, but here, and in most open tubulars, the casing is taken from top-of-the-line racing tubulars. Vittoria uses a fine 320 Threads Per Inch (TPI) cotton/polyester casing for their tubulars and thus uses the same material for their open tubular tires as well.
We've been riding open tubulars for years. We were initially drawn in by the idea of a tubular casing and tread, but once on them won over by the noticeably better ride. The basic idea is that a thinner, more flexible casing deforms more easily at a given pressure and thus both flexes better when going over rough roads and sticks better to the road for better traction. This isn't to say that other racing clinchers don't have a thin, flexible casing, but that the open tubular concept seems to do a bit better much of the time.
The drawbacks to open tubulars are twofold. One is that the tread rubber is on the thin side, so that the tires don't usually last as long as other tires. The second is the thinner casing has proven to be less cut-resistant than other tires. Overall, however, for the convenience of a clincher in racing, we'll take this tradeoff.
We've had several sets of Vittoria Corsa CX EVO Clincher tires over the years. We tested the 25mm version of this tire a few years back and loved it. There was little in the way of new discovery here. We started by weighing the tires: 217g and 218g. This is over the claimed weight by 7-8g. Of course, all manufactured goods vary a little in production and the extra weight was probably in the tread, and that wears off. The tire went onto Zipp 303 Firecrest rims without stretching and without a tool. This is also expected; we don't think we've ever used tire levers to install or remove Vittoria Open Tubulars with any of our wheels.
The tires actually have a directional arrow on them. According to the tires, the forward direction is having the label on the right side. While we don't believe this could make a difference, as tread patterns on road tires doesn't seem to matter, we mounted them the recommended way anyways. The label is thus on the right side of the bike.
The tires have a recommended pressure of 115-145psi. These numbers are definitely high by standards of other tires and higher than what we've seen to be fast in scientific testing. A call to Vittoria yielded the following info: they mark it that way because the high TPI means the tires can be used at those pressures. All the same, Vittoria has a recommended tire pressure chart. According to their chart, you'd have to be over 165lbs to consider putting in over 115psi.
We typically ran the tires at 110 PSI front and rear?Vittoria recommends 110 for the front and 115 for the rear at our weight. We dropped pressure down to 100 PSI for crit racing and 95 PSI for riding in the rain. In all conditions, the tires felt fine. If we didn't have latex tubes inside the tires, we'd probably have let the pressure run down to 75 PSI or less before pumping up again.
In terms of speed, the tires seem to have a real effect. We used the same wheels and tubes for 10k rides at a low threshold pace. One run was on training tires, the next on the Vittoria Corsa CX EVOs. Granted, the efforts were a few weeks apart, but on the same course with the same tire pressure, two degree Fahrenheit difference in temperature, and same power, we gained 25 seconds. Even if we could have more carefully controlled for wind direction and humidity, it seems likely that the tires were much faster.
Now, after over 1200 miles of riding on the tires, the rear tire is showing some signs of wear. The file tread is gone in the back and the crown has flattened. The front tire is still showing the file tread. These tires have been in use daily, have taken in all our regular roads, and have been raced on courses both smooth and rough. No flats, either. Considering how good the tread looks to us, we're wondering if pumping up tires every ride has made a difference as it's hard to believe we've ridden more carefully on these tires.
There's a great feeling when riding these tires, it's nice to have it every day. At the same time, getting this little boost just from race wheels might make the joy of riding them more delicious.