Disc brake for motorcycles

A motorcycle including a front wheel with a brake comprising

• a hub in the wheel having equally spaced bosses projecting from the side of said hub, each of said bosses having two sides parallel to a radial line of said wheel;
• a brake disc mounted on said hub including
• spaced parallel plates, and
• a plurality of radial ribs connecting said plates, said plates defining radially extending cooling passages therebetween;
• pairs of aligned projections at the outer periphery of said spaced plates forming a recess therebetween, said recess having two sides parallel to a radial line of said disc;
• a solid member positioned between said plates at each pair of projections, said solid member formed as a rib having an enlarged rib end portion forming a wall continuously about said recess, said solid member including portions on each side of said recess wider than any said radial rib;
• and
• a cover at the end of each boss to support said disc in an axial position against said hub, said cover offering no resistance to radial movement of said disc, said disc mounted on said hub with each of said recesses engaging a boss, said sides of said recess slidably engaging said sides of said boss for radial heat expansion movement of said disc.