The xt m8000 double 3828 11 speed 148mm boost chainset from shimano is a high performance chainset using the most advanced 11 speed dyna sys chainrings with a plus 3mm outboard chainline for use with 148mm rear axle widths this chainset will allow you to ride anywhere with 11 speed tuned gearing the power to choose how and where you ride the crank arms are forged hollowtech ii with unrivalled strength to weight ratio the lightweight construction teamed with an external super smooth bottom b