The Vittoria Barzo is a classic hardpack race tire. Small, low-profile lugs grip firm, dry trails well and the continuous contact center lug pattern make this one of the fastest off-road tires out there. Lean-dependent sipe angles mean the hard cornering grip doesn’t kick in until the tire is leaned over, which keeps rolling resistance to a minimum and your speed cranked to 11. Counter V-formation channels shed mud and dirt, so you won't get bogged down after riding through some sticky stuff, and the 2.1-inch and 2.25-inch width offerings let you opt for more speed or grip, respectively.
Tread alone doesn't make the tire, though. Almost as important is the casing underneath. Vittoria TNT casing is made from a 120 TPI cloth, which is strong but supple for a smooth feel and good grip. The sidewalls are also reinforced with nylon in order to minimize cuts and folding when riding at lower pressures. Best of all, Vittoria's TubesNoTubes (TNT) bead lets you opt for or against tubes, depending on your preference.
Familiarity: I've used it several times
Like the tires. Nice grip with good damping through rocky bits - and fast on downhill sections. Only downside is they were 40g heavier per tire than the published spec. Vittoria lists this tire at 580g on their site and package however they both weighed in at 620g. Not a small margin... good for training but too heavy for a race tire. If not for this they would get 5 stars.