Bicycle Rear Suspension Linkage for Wheelbase Stability
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Solution Overview
Problem
Mountain bike rear suspension linkages face a tradeoff between effective damping in rough terrain and responsive handling, with traditional designs either compromising control or playfulness and efficiency, due to vertical rear axle paths that shorten the wheelbase and result in instability during cornering.
Innovation Solution
The rear wheel travels up and backward along a path approximately 45 to 90 degrees from the horizontal, aligned as parallel as possible to the front axle path, using a modified Chebyshev Linkage (SYNC Link) to maintain a consistent wheelbase and optimal leverage curve, incorporating an idler pulley and brake mount for efficient motive force transmission and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rear wheel travel is increased to improve damping in rough terrain, then control and traction are improved, but handling responsiveness and playfulness deteriorate
Solution Approach 1:
The patent applies dynamics by making the axle path adjustable rather than fixed. The linkage mechanism allows the rear axle path angle to be dynamically changed based on terrain conditions, enabling the bike to adapt between long-travel damping mode for rough terrain and short-travel responsive mode for smooth terrain, thus resolving the contradiction between control and playfulness
2Device complexity
If traditional vertical rear axle path is used, then suspension compression is simplified, but wheelbase shortening occurs causing instability and oversteering
Solution Approach 1:
The patent segments the suspension linkage into multiple components (linkage mechanism with adjustable angle, pivot points, and connection elements) that work together to maintain a consistent wheelbase. This segmentation allows complex wheelbase stabilization to be achieved through modular components rather than a single complex structure
Solution Approach 2:
The patent changes the parameter of axle path angle from a fixed vertical orientation to an adjustable angle that can be optimized for different conditions. This parameter change prevents wheelbase shortening while maintaining linkage feasibility, resolving the contradiction between simplicity and stability
3Stability of the object's composition
If rear wheel moves up and back to maintain wheelbase, then cornering stability is improved, but motive force transmission efficiency deteriorates
Solution Approach 1:
The patent uses dynamics by allowing the axle path angle to be adjusted based on riding conditions. On smooth terrain, the angle can be optimized for motive force transmission, while on rough terrain, it can be adjusted to prioritize stability, thus resolving the contradiction between cornering stability and energy efficiency
Data Source
AI summary
The present invention is aimed at solving the problems of current bicycle suspension linkages. In particular, it is meant to balance the tradeoff between absorbing impact force, maintaining constant handling characteristics, and efficiently transmitting motive force. The present invention includes an optimal rear axle motion path, and a dual link suspension linkage to accomplish this goal.