Lubrication system and method of lubricating an internal-combustion engine

A gearbox comprising:

• a wall defining a cavity, the wall at least partially enclosing the gearbox;
• a shaft extending through the gearbox, the shaft having a longitudinal axis;
• a gear coupled to the shaft to rotate with the shaft about the longitudinal axis;
• a sliding sleeve coupled to the shaft to rotate with the shaft about the longitudinal axis, the sliding sleeve being adapted to move axially along the shaft;
• a gearshift fork in mating engagement with the sliding sleeve, the gearshift fork moveable in a direction parallel to the longitudinal axis to move the sliding sleeve axially along the shaft;
• and
• a rib extending from the wall into the cavity, the rib positioned so that at least some of a lubricant flung from the shaft, the gear, and the sliding sleeve contacts the rib, the rib being adapted to direct the lubricant onto at least one of the sliding sleeve and the gearshift fork.

A method of lubricating a motorcycle engine, the engine having a gearbox with a wall defining a cavity, the wall at least partially enclosing the gearbox, a rib extending from the wall into the cavity, a sliding sleeve coupled to the shaft to rotate with the shaft about a longitudinal axis, the sliding sleeve adapted to move axially along the shaft, a gearshift fork in mating engagement with the sliding sleeve, the gearshift fork moveable parallel to the shaft, the method comprising:

• rotating the shaft within the gearbox, the shaft coaxial with the longitudinal axis and rotating about the longitudinal axis;
• rotating a gear with the shaft, the gear coupled to the shaft to rotate with the shaft about the longitudinal axis;
• rotating the sliding sleeve with the shaft;
• flinging a lubricant from at least one of the gear, the shaft, and the sliding sleeve;
• collecting at least some of the lubricant on the rib;
• and
• directing the lubricant from the rib onto at least one of the sliding sleeve and the gearshift fork.