Bicycle suspension system

Abstract

There is disclosed herein a suspension fork assembly particularly for use with bicycles. The assembly comprises an outer tube which can be mounted in and extend through the head tube of the bicycle frame, and an inner tube that telescopes within the outer tube. A shock absorbing system, preferably in the form of a cartridge is provided within the tubes. The inner surface of the outer tube and the outer surface of the inner tube each have a plurality of axially arranged opposing longitudinal flat sections, such as four on each tube. A plurality of needle bearings are disposed between the tubes on these flat sections. This arrangement, with the needle bearings arranged on the flat sections between the inner and outer tubes, allows the two tubes to freely telescope in and out with respect to one another without any significant static friction, and also serves to maintain torsional rigidity between the outer tube to the inner tube. The needle bearings thus bear radial loads as well as maintain the in line relationship of the outer and inner tubes for rotational forces while allowing the two tubes to freely telescope. Further, a rigid front blade is secured the inner tube to hold the front wheel of the vehicle and to provide bending and torsional stiffness.