Bicycle Suspension Fork Air Volume Control for Stable Spring Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bicycle suspension forks experience pressure spikes and speed-sensitive return forces due to the casting ramp spring effect, which affects spring rate and consistency, leading to inconsistent riding performance.
Innovation Solution
Incorporating an increased internal air volume within the suspension fork, specifically through a housing that expands the casting volume capacity, reducing pressure spikes and speed sensitivity by maintaining a consistent air volume during compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the casting volume capacity is increased, then pressure spikes are reduced and speed sensitivity is reduced, but the device complexity increases due to additional housing structures
Solution Approach 1:
The patent implements nesting by placing the upper tube inside the lower tube, creating a telescopic suspension fork structure. The upper tube is received within the lower tube, with seals positioned between them to define casting volumes. This nested arrangement allows the suspension components to be compact while maintaining increased air volume capacity, thereby reducing pressure spikes and speed sensitivity without proportionally increasing external dimensions or structural complexity.
Solution Approach 2:
The patent utilizes the internal three-dimensional space within the telescopic tubes to create casting volumes that extend along the length of the tubes. By defining sealed regions between seals positioned at different locations along the upper and lower tubes, the design effectively uses the longitudinal dimension of the telescopic structure to increase air volume capacity without requiring larger external dimensions, thus avoiding excessive structural complexity.
2Reliability
If the air volume is increased to reduce pressure spikes, then the spring rate becomes more consistent, but the volume of the fork increases
Solution Approach 1:
The nested telescopic structure of the upper tube within the lower tube allows the casting volumes to be distributed along the length of the tubes rather than requiring a large external expansion. The seals define sealed regions within the nested configuration, enabling increased effective air volume while maintaining a compact external footprint, thus avoiding significant increases in fork volume.
Solution Approach 2:
The patent exploits the longitudinal dimension of the telescopic tubes to increase air volume. By positioning seals at different locations along the upper and lower tubes to define extended casting volumes, the design increases the effective air space within the existing external envelope of the fork, thereby avoiding the need to increase the overall volume of the moving object.
3Reliability
If seals are positioned to define casting volumes between tubes, then pressure spikes are mitigated, but the device complexity increases due to additional sealing components
Solution Approach 1:
The seals in the patent serve multiple functions simultaneously: they prevent fluid leakage between the upper and lower tubes, define the boundaries of the casting volumes, and contribute to the structural integrity of the telescopic assembly. By making the sealing components multi-functional, the design achieves pressure stability and consistent spring rate without requiring additional dedicated components, thereby avoiding excessive device complexity.
Solution Approach 2:
The patent merges the sealing function with the structural function by integrating the seals into the telescopic tube assembly where they simultaneously provide fluid containment and define the geometric boundaries of the casting volumes. This consolidation of functions into existing components rather than adding separate dedicated structures reduces the overall device complexity while achieving the desired pressure stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The increased air volume mitigates pressure spikes and reduces speed-sensitive return forces, providing a more consistent riding experience by stabilizing the spring rate and damping performance.
Implementation Method 1
the casting ramp spring effect... affecting spring rate and consistency... pressure spikes and speed-sensitive return forces... increased internal air volume... reducing pressure spikes by maintaining a consistent air volume during compression
Data Source
AI summary
Suspension forks for bicycles are described herein. An example suspension fork includes a first tube and a second tube slidably received within the first tube. The first tube includes an outer mounting portion. A first volume is disposed between the first tube and the second tube. A sealing element is provided for sealing the first volume between the first tube and the second tube. A volume control element is removably attachable to the outer mounting portion of the first tube, wherein the volume control element is operable to change a magnitude of the first volume disposed between the first tube and the second tube.