Product Test: Pirelli Scorpion Tires
Pirelli has been making tires for two- and four-wheel motorsports since 1872, and now they are applying all that experience to mountain biking. Pirelli’s first mountain bike product aims to reduce confusion when purchasing a tire. Designed to be terrain-specific, the Scorpion tires come in four versions: Hard Terrain, Mixed Terrain, Soft Terrain and Rear Specific.
Tech features: All four choices are available in 27.5-inch and 29-inch wheel sizes. The 27.5-inch comes in two widths—2.4 and 2.6 inches—and the 29-inch comes in three widths: 2.2, 2.4 and 2.6 inches. Every tire in the line is tubeless ready with a standard 60 tpi (thread-per-inch) casing. The 29-inch tire is also offered in a lighter-weight “Lite” casing with 120 tpi that can be found in the 2.2- and 2.4-inch widths, but in the rear-specific model.
SmartGRIP is Pirelli’s rubber compound that was developed to work in all conditions—producing traction in dry terrain while retaining wet-weather grip. Using the single compound, Pirelli then slightly modified each tire’s knob width, height and spacing to better suit the performance needs in different conditions.
Field test results: The Scorpion is designed for wide rims. Pirelli suggests using a 25mm inner rim width with the 2.2-inch tire and using the 2.4- and 2.6-inch tires with rims of at least 30mm inner width. Pairing the tire with the correct rim will give the tire appropriate volume for its application—a narrower tire and rim can deliver more energy-efficient performance, while a wider tire and rim can support more aggressive riding.
For our test, we chose to outfit a few 29ers with a combination of Scorpions before settling on the Mixed Terrain up front and a Hard Terrain in the rear. Let’s break down the performance of each.
Using the Mixed Terrain (M label) up front, we found it capable of delivering bite in a range of soft to hard terrain. The M-label tire performed consistently and was reliable when cornering. The outer knobs of the tire could dig in to claw around turns and would not break loose without warning. The M label encouraged leaning the bike into turns and helped carry momentum when changing direction. Compared to the rest of the Scorpion family of tires, the Hard Terrain (H label) has the most plentiful, smallest and most tightly packed tread blocks. This design produced a faster-rolling tire that worked well in the rear. On hardpack, compact surfaces, the wide center patch of knobs created a broad footprint that offered powerful braking performance when needed.
Mounting the Scorpions took some effort. Though they were not the hardest tires to install that we’ve encountered, it took a little extra muscle to seat the bead on the wheelsets; however, once we hit the dirt, the Scorpion tire’s casing proved compliant, molding to the contours of the trail, including rocks and roots. Beyond the knob and rubber compound’s ability to provide traction, the whole tire, from the bead through the casing, offered enough pliability to create grip when needed. And, unlike multi-rubber compound tires, Pirelli’s use of a single rubber compound ensures even greater durability as the knobs wear down over time.