Bicycle Frame Derailleur Mounting Element with Plastic-Metal Hybrid

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Solution Overview

Problem

The assembly of rear derailleurs on bicycle frames is complicated due to varying positioning differences caused by different switching barrels, leading to potential damage and interference in the chain transmission, especially during gear changes or crashes.

Innovation Solution

A holder element made of a combination of plastic and metal, with the plastic section being injection-molded to fit specific geometries and tolerances of the bicycle frame and derailleur, providing a stable and durable connection that compensates for manufacturing tolerances and reduces interference in the chain transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate derailleur hangers are used to attach the rear derailleur to the bicycle frame, then the derailleur can be mounted with adjustable positioning, but the assembly becomes more complex and requires additional components

Engineering Contradiction:
Improvepositioning adjustmentVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the derailleur hanger with the bicycle frame into a single integrated component. The frame includes a mounting section with a mounting opening that directly receives the derailleur base element, eliminating the need for separate hanger components. This integration maintains positioning adjustability through the mounting opening design while reducing assembly complexity by removing intermediate parts.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mounting section of the frame serves multiple functions: it provides structural support as part of the frame, creates the mounting opening for derailleur attachment, and enables positioning adjustment. This multi-functionality reduces the need for dedicated separate components while maintaining the required adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If derailleur hangers are clamped to the frame using quick-release axles or thru-axles, then assembly is simplified, but positioning precision and stability are reduced

Engineering Contradiction:
Improveassembly easeVSAvoidpositioning precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

By integrating the hanger function into the frame's mounting section, the patent eliminates the need for separate clamping mechanisms like quick-release axles or thru-axles. The mounting opening is directly formed in the frame structure, providing both precise positioning and stable attachment without requiring additional clamping components.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the derailleur hanger is positioned radially offset from the rear wheel axle, then the derailleur can be mounted, but positioning variations between different hangers complicate derailleur design and installation

Engineering Contradiction:
Improvemounting flexibilityVSAvoiddesign complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mounting section integrates multiple functions including radial offset positioning, structural support, and alignment reference. By incorporating the positioning geometry directly into the frame's mounting section, the patent establishes a universal reference point that simplifies derailleur design while maintaining the necessary radial offset for proper derailleur positioning.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 holder element ensures precise positioning and stability, reducing the risk of damage to the bicycle frame and chain circuit, and allows for quick assembly and adjustment, minimizing disruptions in power transmission.

Implementation Method 1

The holder element (1, 101) is formed with at least one plastic-made region (2) and one metal-made region (3), wherein the plastic-made region (2) is firmly connected to the metal-made region (3)

Methodology Applied
Scientific EffectInjection molding:

Data Source

PatentEP4063250B1Support element and bicycle comprising a support element
Publication Date: 2025.02.12 SRAM
  • EP4063250B1 patent drawingFigure 1
  • EP4063250B1 patent drawingFigure 2a~2b
  • EP4063250B1 patent drawingFigure 3a~3b

AI summary

According to one aspect of the invention, it provides a mounting element designed to connect a bicycle frame to a rear derailleur of a derailleur system, wherein the mounting element comprises a first section having an opening or recess for receiving a section of a bicycle rear axle, and a second section having a mounting opening to which a base element of the rear derailleur can be attached. According to the invention, the mounting element is designed with at least one area made of plastic and one area made of metal, and the plastic area is rigidly connected to the metal area.According to a further aspect of the invention, it provides a bicycle which includes a retaining element with a deflecting surface area on which a bicycle chain, when it has jumped off a sprocket of a sprocket set, can rest and then slide down towards the smallest sprocket in order to restore the engagement of the chain with a sprocket of the sprocket set.