Bicycle Front Fork Buttress for Lateral Stiffness and Lower Weight
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Solution Overview
Problem
Prior art front fork assemblies require added material for lateral stiffness, increasing weight and limiting the amount of stiffness that can be achieved due to the diameter of the tubes used.
Innovation Solution
A bicycle frame with a front fork assembly featuring a buttress that tapers in width and is disposed forward of the head tube, providing enhanced lateral stiffness with reduced material usage, and a rotational limiting device to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If material is added to the connection between fork legs and the fork crown to provide lateral stiffness, then lateral stiffness is improved, but weight increases
Solution Approach 1:
The patent applies local quality by creating a buttress structure with varying thickness - thicker at the base where lateral stiffness is most needed, and tapering to thinner sections toward the top. This localized material distribution provides maximum structural support exactly where the fork legs connect to the crown, while minimizing material usage in areas where less support is required, thereby reducing overall weight while maintaining lateral stiffness.
Solution Approach 2:
The patent introduces a new dimensional element by adding the buttress structure that extends forward from the head tube area. This creates an additional structural dimension that reinforces the fork assembly's lateral stiffness without simply increasing the diameter of existing tubes. The buttress projects forward to provide a broader base of support, effectively using spatial arrangement to achieve stiffness goals.
2Strength
If material is added to the connection between the fork crown and the steerer tube to provide lateral stiffness, then lateral stiffness is improved, but weight increases
Solution Approach 1:
The buttress structure implements local quality by concentrating material where it is most effective - at the base of the fork crown where it connects to the head tube and steerer tube area. The varying thickness design ensures maximum reinforcement at the critical connection point while reducing material toward the top, providing lateral stiffness support without proportionally increasing weight throughout the entire fork assembly.
Solution Approach 2:
The patent adds structural support in a new dimension by projecting the buttress forward from the head tube area. This creates an extended structural element that reinforces the connection between the fork crown and steerer tube without simply increasing tube diameters. The forward projection provides a broader structural foundation that enhances lateral stiffness through spatial arrangement rather than just adding material volume.
3Strength
If the diameter of tubes is increased to provide more lateral stiffness, then lateral stiffness is improved, but weight increases
Solution Approach 1:
Instead of uniformly increasing tube diameters throughout the fork assembly, the patent applies local quality by adding the buttress structure only where it is most needed - at the base of the fork crown. This localized reinforcement provides the necessary lateral stiffness support without increasing the diameter of the fork legs or other tubes, thereby minimizing weight increase while achieving the stiffness goal.
Solution Approach 2:
The patent solves the stiffness problem by introducing a new structural dimension - the forward-projecting buttress - rather than simply increasing tube diameters. This creates an additional structural element that provides lateral stiffness through its spatial arrangement and leverage, effectively achieving stiffness enhancement without the weight penalty of larger diameter tubes throughout the assembly.
4Quantity of substance
If a buttress with varying width is used to provide lateral stiffness, then material usage is reduced, but manufacturing complexity increases
Solution Approach 1:
The varying width of the buttress is designed to match the local structural requirements - wider at the base where support is needed and tapering toward the top. This local quality approach optimizes material usage by placing material only where structurally necessary, reducing overall material consumption while maintaining strength. The gradual taper simplifies manufacturing compared to complex variable geometry, as it can be achieved through standard forming or molding processes.
Solution Approach 2:
The buttress employs smooth curved transitions and tapered geometry rather than sharp angles or complex variable sections. This use of curvature and gradual transitions simplifies manufacturing by allowing the use of standard forming, molding, or machining processes, while still achieving the material reduction goal through the optimized varying width profile.
Data Source
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AI summary
A bicycle according to the present disclosure comprises a frame assembly and a front fork. The frame assembly includes a head tube defining a steering axis. The front fork is rotatably coupled to the head tube and includes upper and lower supports aligned with the steering axis. The upper and lower supports project away from the fork assembly and rotationally couple the front fork assembly to the head tube. A buttress is coupled to the upper and lower supports at upper and lower buttress ends. A pair of laterally spaced fork legs project from the buttress lower end at one end of the fork legs. The buttress is disposed forward of the head tube and has a lateral width which tapers from a first width at the buttress lower end to a second width at the buttress upper end.