Bicycle Seat Post Struts for Torsional Rigidity and Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Racing bikes lack a seat post that balances torsional rigidity with flexibility to improve comfort and handling, as existing solutions are either too heavy or compromise on torsional rigidity.
Innovation Solution
A seat post design featuring two hollow profile struts with a contact surface at the frame-side end, allowing for increased flexibility while maintaining sufficient torsional rigidity, which are connected to the seat tube via a seat clamp without the need for a connecting element, and can be made of fiber composite materials with varying cross-sections and wall thicknesses for optimal load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If spring-loaded rear structures or damped seat posts are used to improve comfort, then flexibility is improved, but weight increases making them unsuitable for racing bikes
Solution Approach 1:
The seat post is divided into multiple separate struts (typically three) that can move independently relative to each other. This segmentation allows each strut to provide flexibility through relative movement while maintaining a lightweight overall structure suitable for racing bikes, avoiding the need for heavy spring-loaded mechanisms.
Solution Approach 2:
The struts are designed to be dynamically movable relative to one another, allowing the seat post to adapt to road conditions through relative strut movement. This dynamic configuration provides comfort through flexibility without requiring heavy damping mechanisms, as the movable struts naturally absorb vibrations.
2Stability of the object's composition
If flexible plastic struts are used to improve comfort, then flexibility is improved, but torsional rigidity decreases impairing bike handling
Solution Approach 1:
The struts are constructed from composite materials, specifically carbon fiber reinforced plastic (CFRP), which provides both flexibility and high torsional rigidity. This composite material allows the struts to be lightweight and flexible for comfort while simultaneously maintaining sufficient torsional stiffness for proper bike handling.
Solution Approach 2:
The struts have varying wall thicknesses along their length, with thicker sections where higher strength is needed and thinner sections where flexibility is prioritized. This local variation in quality allows the structure to achieve both flexibility for comfort and sufficient torsional rigidity for handling by concentrating material where most needed.
3Strength
If connecting elements are added between struts to fill gaps, then structural integrity is improved, but device complexity increases
Solution Approach 1:
The connecting element is merged with the struts themselves, forming an integrated structure where the struts and connector are essentially one piece. This eliminates the need for separate connecting components and simplifies the overall structure, reducing assembly steps and potential failure points while maintaining structural integrity.
Solution Approach 2:
The connecting element serves multiple functions simultaneously: it joins the struts together, provides structural support, and maintains the hollow profile configuration. This multi-functionality reduces the need for additional specialized components, thereby reducing overall device complexity.
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 design enhances comfort and handling by providing improved flexibility and torsional rigidity, reducing the weight and complexity of the seat post, making it suitable for racing bikes without the need for additional components.
Implementation Method 1
the struts are designed as hollow profiles in their frame-side end region... sufficient torsional rigidity, at least in their frame-side end region as a hollow profile
Data Source
Figure 1~4
Figure 5~6
Figure 7
AI summary
A seatpost for bicycle saddles, particularly for racing bikes, has two struts (10). The struts (10) are connected to a head element (26) for connection to a saddle element (44). In their frame-side end region (12), the two struts (10) are designed as hollow profiles. Preferably, the two struts (10) have a semicircular cross-section in this region, so that a common contact surface (16) is formed.