Bicycle Stem System Internal Clamping for Aerodynamic Design

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Solution Overview

Problem

Conventional stem systems for bicycles limit design options due to clamping means being arranged above the fork tube or head tube, restricting aerodynamic designs and handlebar configurations.

Innovation Solution

A stem system with a clamping device that projects through a peripheral insertion opening in the fork shaft, allowing for internal clamping and the use of intermediate elements for enhanced clamping force distribution, along with adjustable stem shaft height and flexible stem designs for improved shock absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clamping device is arranged above the fork tube or head tube, then the stem can be securely clamped, but the design possibilities for aerodynamic shapes and handlebar configurations are limited

Engineering Contradiction:
Improveclamping securityVSAvoiddesign possibilities
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The clamping device is nested inside the steerer tube, with the clamping element projecting through an insertion opening in the circumferential surface. This allows the clamping mechanism to be housed within the existing structural volume of the steerer tube, eliminating the need for external clamping components above the fork tube while maintaining secure stem attachment.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The clamping element is positioned in the longitudinal dimension within the steerer tube, projecting through an insertion opening in the circumferential surface. This dimensional repositioning moves the clamping action from the external region above the fork tube to the internal region within the steerer tube, freeing up space for aerodynamic design modifications.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If the clamping means are arranged above the fork tube, then assembly is straightforward, but the aerodynamic profile and frame configuration flexibility are restricted

Engineering Contradiction:
Improveassembly simplicityVSAvoidaerodynamic profile
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The clamping device is integrated within the steerer tube structure, utilizing the existing cylindrical space. The clamping element projects through an insertion opening in the circumferential surface, allowing assembly tools to access the clamping mechanism from the external side while maintaining a clean, aerodynamic external profile without protruding clamping components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stability of the object's composition

If the stem is fixed in position, then structural stability is maintained, but adjustability for different riding conditions is reduced

Engineering Contradiction:
Improvestructural stabilityVSAvoidposition adjustability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The stem is provided with an adjustment mechanism that allows it to be positioned at different heights and angles relative to the steerer tube. The clamping device maintains secure attachment while enabling dynamic repositioning of the stem within defined limits, allowing riders to adjust the handlebar configuration for different riding conditions while maintaining structural integrity.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3786046B1Stem system
Publication Date: 2023.10.04 CANYON BICYCLES
  • EP3786046B1 patent drawingFigure 1
  • EP3786046B1 patent drawingFigure 2~3

AI summary

A stem system for bicycle handlebars comprises a steerer tube (10) and a stem (16). The stem (16) projects into the steerer tube (10). A clamping device (18) arranged inside the steerer tube (10) enables a clamping connection between the stem (16) and the steerer tube (10). According to the invention, the clamping device (18) has a clamping element (20) such as a screw, which projects into the steerer tube (10) through an insertion opening (22).