The Metzeler Six Days Extreme Hard 80/100-21 51M is a front enduro competition tire designed specifically for hardpack and rocky terrain. Developed in the FIM Enduro World Championship, this version uses a harder rubber compound for maximum durability, stability, and resistance to chunking in extreme conditions. Its tread block design provides precise steering feedback, excellent braking stability, and reliable grip on compact and rocky surfaces. The reinforced polyester carcass improves impact absorption and handling under aggressive riding, while maintaining consistent performance throughout long stages. With a 51M load/speed rating, this tire is competition-ready and ideal for riders tackling hard enduro events where durability and precision are key.