Bicycle Frame Adjustable Geometry via Eccentric Cam Assembly
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Solution Overview
Problem
Current bicycle frames lack the ability to easily adjust geometry without changing components, limiting adaptability to different riders and terrains, which affects riding characteristics such as comfort, pedaling efficiency, and handling.
Innovation Solution
Incorporation of a double eccentric cam assembly within pivot joints of the rear wheel suspension system, allowing adjustable pivot axes to modify the frame geometry, enabling adjustments to suit various riding styles and conditions without replacing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the bicycle frame geometry is fixed during manufacturing, then the manufacturing precision and structural stability are improved, but the adaptability to different riders and terrains deteriorates
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed frame geometry into an adjustable system. The double eccentric cam assemblies enable the pivot points of the rear suspension to be repositioned dynamically, allowing the frame geometry to adapt to different riding conditions and rider preferences without compromising manufacturing precision. The cams can be rotated to different positions and locked, providing discrete geometry adjustments while maintaining structural integrity.
Solution Approach 2:
The patent implements parameter changes by modifying the position parameters of the suspension pivot points through the eccentric cam mechanism. By rotating the cams, the effective length and angle of suspension links change, thereby altering frame geometry parameters such as head tube angle, seat tube angle, and chainstay length. This allows a single frame to provide multiple geometry configurations.
2Adaptability or versatility
If multiple frame sets are manufactured with different geometries, then the adaptability to different riding styles is improved, but the device complexity and inventory requirements deteriorates
Solution Approach 1:
The patent applies universality by designing a single frame structure that can perform multiple geometry configurations. The double eccentric cam assemblies are integrated into the existing frame and suspension components, allowing one frame set to replace what would traditionally require multiple different frame sets. This multi-functional design enables the same frame to be optimized for different riding styles such as cross-country, all-mountain, or downhill.
Solution Approach 2:
The dynamics principle is applied to transform a static frame into a dynamic, adjustable system. The eccentric cams provide mechanical adjustability that allows users to change geometry on-demand, eliminating the need to manufacture and inventory multiple frame variants. This reduces complexity in the supply chain and retail inventory while maintaining adaptability to different riding preferences.
3Stability of the object's composition
If the pivot points are fixed in position, then the structural stability and manufacturing simplicity are improved, but the ability to adjust suspension characteristics deteriorates
Solution Approach 1:
The patent applies dynamics by making the previously fixed pivot points adjustable through the eccentric cam mechanism. The cams are mounted on rotation axes that allow the effective pivot position to be changed while maintaining a stable, locked position during riding. This provides structural stability when locked but enables adjustment when needed, resolving the contradiction between stability and adaptability.
Solution Approach 2:
The patent applies segmentation by dividing the suspension system into adjustable modules. The double eccentric cam assemblies are separate, interchangeable components that can be independently adjusted or replaced. This modular approach allows the pivot positions to be modified without affecting the overall structural integrity of the frame and suspension system.
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 adjustable pivot axes significantly change the bicycle's geometry, enhancing flexibility and adaptability to different riders and terrains, improving performance and comfort by altering suspension travel, rate, and force distribution.
Implementation Method 1
an inner eccentric cam and an outer eccentric cam which when nested together and interlocked prevent relative rotation therebetween, the inner and outer eccentric cams being interlocked by a transversely extending fastener passing through an aperture in said inner eccentric cam such as to define a pivot axis, the aperture in the inner eccentric cam being eccentric relative to a perimeter of the inner eccentric cam, the inner eccentric cam being receiving within a correspondingly shaped opening in said outer eccentric cam which is itself eccentric relative to a perimeter of the outer eccentric cam
Data Source
AI summary
A bicycle frame set includes a main frame, a rear wheel suspension pivotally attached to the main frame, and a double eccentric cam assembly disposed within one or more pivot joints between the main frame and the rear wheel suspension. The double eccentric cam assembly includes inner and outer eccentric cams removably fastened together and retained in place within the pivot joint by a removable fastener passing through an aperture in the inner eccentric cam and defining a pivot axis. The aperture is eccentric relative to a perimeter of the inner eccentric cam. The inner cam is received within a correspondingly shaped opening in the outer cam which opening is itself eccentric relative to a perimeter of the outer eccentric cam. A rotational position of each of the cams is thus adjustable, so as to change a relative location of the pivot axis of the pivot joint.