Modular Bicycle Stem with Interchangeable Intermediate Element

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Solution Overview

Problem

Existing handlebar stems for bicycles are either heavy, require significant assembly effort for adjustments, or lack secure fixation, making it difficult to change the inclination and length without replacing the entire stem, which is costly and inefficient.

Innovation Solution

A modular handlebar stem design featuring a first clamping element for the steerer tube, a second clamping element for the handlebar, and a detachable intermediate element that can be easily replaced to adjust length and inclination, ensuring secure fixation through a positive connection and minimal assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a joint with horizontal axis is used to change the inclination of the steering stem, then the inclination can be adjusted, but the handlebar stem becomes very heavy

Engineering Contradiction:
Improveinclination adjustmentVSAvoidhandlebar stem weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The handlebar stem is divided into three separate components: a first clamping element for the steerer tube, a second clamping element for the handlebar, and an interchangeable intermediate element. This segmentation allows the intermediate element to be replaced with different versions (including swiveling versions) without replacing the entire stem assembly, thereby reducing overall weight while maintaining adjustment functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The intermediate element is designed to be interchangeable, allowing the user to switch between a fixed intermediate element (for weight savings) and a swiveling intermediate element (for inclination adjustment). This dynamic configuration enables the system to adapt its functionality based on needs without permanently increasing weight.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the complete handlebar stem is replaced to change length or inclination, then the seating position can be improved, but the assembly effort and cost increase significantly

Engineering Contradiction:
Improveseating position adjustmentVSAvoidassembly effort
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

By segmenting the handlebar stem into replaceable components (specifically the intermediate element), the system allows adjustment of length and inclination by replacing only the intermediate element rather than the entire stem. This reduces assembly effort and time while achieving the desired seating position changes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design allows the intermediate element to be easily removed and replaced with a different length or inclination version, while the first and second clamping elements are retained and reused. This minimizes waste and reduces the time and effort required for adjustments.

Inventive Principle:
Principle #34Discarding and recovering

3Weight of moving object

If a tubular intermediate element is inserted into recesses and fixed by clamping, then the handlebar stem becomes lighter, but secure fixation is not guaranteed and the intermediate element may slip out

Engineering Contradiction:
Improvehandlebar stem weightVSAvoidfixation security
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The fixation system is segmented into multiple independent mechanisms: positive connection elements (protrusions and recesses) for preventing rotational movement, and clamping elements with retaining screws for preventing axial displacement. This segmented approach ensures reliable fixation while maintaining a lightweight design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design combines multiple fixation mechanisms (positive connection for rotation prevention and clamping for axial prevention) into a unified system that secures the intermediate element reliably without requiring excessive weight or complex structures.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If swiveling steering stems or length-adjustable stems are used, then inclination or length can be changed, but the handlebar stem becomes very heavy

Engineering Contradiction:
ImproveadjustabilityVSAvoidhandlebar stem weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The handlebar stem is segmented so that only the intermediate element needs to be replaced for adjustments, rather than the entire stem. This allows the use of swiveling or adjustable intermediate elements without the full weight penalty of a completely adjustable stem.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The intermediate element is designed as a relatively simple, interchangeable component that can be replaced easily. This allows the use of adjustable or swiveling versions without committing to a heavy, permanently integrated design, effectively treating the intermediate element as a replaceable accessory rather than a permanent structural component.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP2308749B1Stem for bicycle handlebars
Publication Date: 2017.06.07 CANYON BICYCLES
  • EP2308749B1 patent drawingFigure 1~2
  • EP2308749B1 patent drawingFigure 3

AI summary

The stem has a clamping element (10) for connecting with a fork tube by two screws, and another clamping element (14) for holding a steering wheel. An intermediate element (24) arranged between the clamping elements and detachably connected with the clamping elements. The intermediate element or the clamping elements comprise a recess, where an attachment piece is inserted into the recess. A retaining element (38) interconnects the two clamping elements, and the intermediate element is tubularly formed in longitudinal direction.