He apparently caught his own reflection in the handlebar mirror, and became so aroused by it that he burst his Speedo shorts which then got caught in the gears and just threw him on his face, splatter.
Ta märkas ilmselt iseenda peegeldust leistangi peeglist ja läks... sellest nii närvi, et jäi oma pükse pidi... hammasrataste vahele, mistõttu ta maha lendas.