DIY recumbent bicycle made from recycled parts

Step 3: The bottom bracket triangle

The bottom bracket triangle was designed to have pivoting at all tree vertices to utilize the spring action of the suspension fork. The chain stays with the bottom bracket from a the sacrificed bicycle frame makes up one side of the triangle; the suspension fork is its second side; and the third upper side is made from the inside tube steering column of an old Razor scooter.  The front end of the triangle is pivoted at the bottom bracket and the trailing end is pivoted at a bracket hammered into proper shape from a piece of tubing. This bracket is rigidly mounted inside the top of the fork with a bolt and a conical nut that is jammed inside against the steering column's butted end by tightening the bolt.