Motorcycle fork bottom which is stiffer front-to-back than side-to-side

Abstract

A motorcycle or bicycle suspension having adjustable side-to-side flexibility. The suspension includes a telescopic fork and a fork bottom which couples the fork to the axle of a wheel. The fork bottom and the fork are stiff in the direction of travel, to avoid flexing under heavy braking. The fork bottom is flexible in the lateral direction, to improve the ability of the tire to stay in contact with the ground when leaned over and cornering over irregular, bumpy ground. The lateral flexibility of the fork bottom is adjustable by tightening or loosening a tension cable which is attached to the ends of the fork bottom and stretched over a fulcrum in the middle of the fork bottom. Tightening the tension cable increases sideways thrust of the fulcrum against the fork bottom, reducing the lateral flexibility of the fork bottom.

Description

RELATED APPLICATION [0001] This application is a continuation of co-pending application Ser. No. 10 / 634,041 entitled “Motorcycle Fork Bottom Having Different Longitudinal Stiffness and Adjustable Sideways Stifffiess” filed Jul. 31, 2003 by this inventor.BACKGROUND OF THE INVENTION [0002] 1. Technical Field of the Invention [0003] This invention relates generally to suspension components for two-wheeled vehicles, and more specifically to front fork components. [0004] 2. Background Art [0005] The vast majority of motorcycles are equipped with a sliding-tube or telescopic front suspension, consisting of a pair of forks coupled to the front axle and to the steering head of the motorcycle's frame. The forks are either of the “right-side-up” or sliding-female configuration, or the “upside-down” or sliding-male configuration. In either case, a cylindrical tube or piston slides axially within a generally cylindrical cylinder. As a motorcycle rider applies the front brake, the front forks ar...

AI Technical Summary

Problems solved by technology

Fork flex, especially under braking, is a significant contributor to the stiction which is known to dramatically reduce the effectiveness and perceived quality of a motorcycle's front suspension.

These engineering changes have an unfortunate side effect, which is exposed by the fact that motorcycles lean to the inside when cornering.

The forks' stiffness, which the engineer gave the fork tubes to counteract flex under braking, is now doing exactly the wrong thing with respect to the force of the bump—it is fighting the bump, rather than supplely allowing the front tire to track the road surface and remain in contact with the ground.

The result is often a front end push which may end in a crash.

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