Vehicle body frame for motorcycle

A vehicle body frame for a motorcycle for mounting a front fork and a rear fork comprising:

• an engine;
• a pair of right front and left front frame members, said right and left front frame members being secured to each other and extending forwardly and upwardly relative to said engine and having a predetermined vertical width to form a support for a front fork of a motorcycle at each upper front end thereof and being spaced relative to each other to form an interior portion for retaining said engine therebetween;
• bosses being formed on an internal lateral wall of each of said pair of front frame members and projecting from said internal lateral wall to be contacted and connected to each other in face-to-face relation for forming a predetermined lateral interval therebetween;
• a rear frame including a right rear frame member and a left rear frame member, said right and left rear frame members being secured to each other to form a support for a rear fork of a motorcycle and to form an interior portion for retaining said engine therebetween;
• a fuel tank being positioned in an open space formed rearwardly of said front frame members and above said engine;
• and
• a seat rail mounted at a front end on each of said rear frame members and extending rearwardly of the rear frame members toward and above said rear fork;
• respective lower rear ends of said front frame members being secured on opposite sides of said engine at two spaced upper and lower portions and at said predetermined lateral interval and said rear frame members being secured to said engine for forming the motorcycle body frame with said engine being one of the elements of the body frame.