Bicycle Stem Length Adjustment via Segmented Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bicycle stem technologies require numerous manufacturing molds and are expensive due to the need for various lengths to accommodate different user preferences, and they often compromise on adjustability and safety, particularly for carbon steerer tubes.
Innovation Solution
A bicycle stem assembly with a clamping organ featuring an oblong symmetric clamping opening and complementary shaped insert parts that allow for flexible length adjustment and reliable clamping, minimizing the need for multiple molds and ensuring safety for carbon steerer tubes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different lengths of stem body are manufactured to accommodate user preferences, then the adaptability for different users is improved, but the manufacturing complexity and cost increase due to requiring multiple manufacturing molds
Solution Approach 1:
The stem body is divided into a main stem body and a separate adjustable extension element. The extension element can be inserted and secured at different positions along the stem body, allowing length adjustment without requiring multiple complete stem body molds. This segmentation enables continuous or stepped length adjustment while using a single base manufacturing mold.
Solution Approach 2:
The stem assembly transitions from a fixed length design to a dynamically adjustable length design. The extension element can be positioned at multiple locations along the stem body and secured using clamping mechanisms, allowing the effective length to be changed based on user preference. This dynamic adjustment capability replaces the need for multiple static stem body variants.
2Adaptability or versatility
If angular adjustment mechanisms are added to change handlebar orientation, then the adaptability for different riding positions is improved, but the device complexity increases and the clamping mechanism becomes more vulnerable
Solution Approach 1:
The angular adjustment function is merged with the existing length adjustment mechanism. The extension element serves dual purposes: it adjusts the stem length and provides the angular adjustment capability through its rotational connection to the main stem body. This integration eliminates the need for a separate angular adjustment mechanism, reducing overall device complexity.
Solution Approach 2:
The extension element is designed as a multi-functional component that performs both length adjustment and angular orientation adjustment. By rotating the extension element to different angles and securing it at various positions, the system achieves both linear and angular adaptability from a single component, rather than requiring separate mechanisms for each function.
3Reliability
If the clamping opening is made smaller to accommodate carbon steerer tubes, then the safety and protection of carbon steerer tubes is improved, but the ease of operation for inserting and removing the stem is reduced
Solution Approach 1:
Alignment features such as guide ribs or tapered leading edges are provided on the extension element and stem body to pre-align the components before final insertion. This preliminary alignment action ensures that even with a smaller, more protective clamping opening, the stem can be easily and correctly inserted without forcing or misalignment that could damage carbon steerer tubes.
Solution Approach 2:
A tapered guide section or alignment feature acts as an intermediary between the larger external dimensions and the smaller internal clamping opening. This intermediary feature gradually transitions the material flow and guides the stem into the correct position, facilitating easy insertion while maintaining the integrity and protection of the carbon steerer tube within the smaller clamping opening.
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
Enables easy, quick, and flexible length adjustments with reliable clamping, reducing manufacturing costs and protecting carbon steerer tubes from pinching risks, while allowing for a range of length options without compromising on adjustability.
Implementation Method 1
A wedge member can be placed from below into this cavity such that it comes to lie with a convexly curved inner clamping face against the steerer tube and with an angled clamping face slideable along a wall of the cavity. A bolt is provided with which the wedge member can be pulled tighter into the cavity while at a same time getting to exert an increasing clamping force onto the steerer tube.
Implementation Method 2
An operable clamping organ is provided for clamping the steerer tube inside the clamping opening. The clamping organ has at least one operable insert part that is destined to lie with an inner clamping face against the steerer tube and with an outer clamping face against the clamping opening and that is tightenable for exerting a clamping force between the clamping opening and the steerer tube for fixedly connecting the stem body to the steerer tube.
Data Source
Figure 1a
Figure 1b
Figure 2~9
AI summary
An assembly of a bicycle stem and one or more clamping organs, comprises a stem body (1) with a clamping opening and at least one clamping organ for clamping a steerer tube (25) inside the clamping opening. The clamping opening has symmetric opposing end sections. Those opposing end sections as well as inner and outer clamping faces (18, 19) of one or more insert parts (12) of a clamping organ are shaped complementary to outer circumferential parts of an upper end of the steerer tube, such that the at least one insert part of the clamping organ is positionable in two different rotational positions on either side of the steerer tube inside the clamping opening for adjusting a distance between the steerer tube and the handlebar.