The 27. 5in Trail King is a large volume tire that uses Continental's ProTection casing with Apex sidewalls to make it ideal for long-travel mountain bikes with mid-size wheels. Available in both 2. 2- and 2. 4-inch widths, the Apex sidewall design uses a strip of additional material above the bead that helps stiffen the sidewall. This increases tire stability and control in hard turns and off-camber terrain. The extra sidewall support also means that you can run slightly lower tire pressures without worrying about burping your tires or losing control. The Black Chili compound is a synthetic rubber with nano-sized particles to react to surface irregularities more effectively. This not only improves grip, but these particles also form a tighter bond to improve compound strength, lengthening tread life and reducing the chances that lugs will rip and tear. Compared to Continental's earlier-generation tire compound, Black Chili tires provide 20% less rolling-resistance, 30% more grip, and an improved tread life of around 5%. The tread pattern is aggressive and designed for loose and rocky scenarios. Staggered side knobs and siping provide excellent traction over a variety of surfaces. The Continental Trail King Tire comes in either 2. 2 or 2. 4in widths and with a black sidewall only.