Direct-Mount Bicycle Derailleur With Angled Pivot Axes

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Solution Overview

Problem

Bicycle derailleurs face challenges in mounting directly to sturdy bicycle frames without intervening hangers, especially when incorporating compact motorized components, and require separate hangers that complicate maintenance and alignment with driven sprockets.

Innovation Solution

A bicycle derailleur design featuring a base member with spaced mounting portions and angled pivot axes, allowing direct mounting to the frame, accommodating slanted links, and integrating a battery mount for compact motor operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate derailleur hanger is used to attach the derailleur to the frame, then the derailleur can be mounted on frames with various shapes and manufacturers' specifications, but the device complexity increases and maintenance becomes more inconvenient

Engineering Contradiction:

Improvecompatibility with various frame shapes and manufacturersVSAvoidnumber of separate components

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the derailleur base member with the mounting function by integrating directly onto the bicycle frame, eliminating the separate hanger component. The base member includes mounting portions that directly interface with the frame, combining what were previously separate functions into one integrated unit.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The base member is designed with universal mounting portions that can accommodate various frame shapes and manufacturers' specifications through standardized mounting interfaces. The mounting portions include features that adapt to different frame geometries while maintaining a single integrated structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If a separate derailleur hanger is used, then the hanger can be designed to break or bend to limit damage to the frame, but the ease of repair decreases due to additional maintenance requirements

Engineering Contradiction:

Improvedamage protection to frameVSAvoidmaintenance complexity

Core Design Contradiction:

Object-affected harmful factorsVSEase of repair

Solution Approach 1:

The patent extracts the sacrificial protection function from a separate hanger and integrates it into the base member structure. The mounting portions are designed to be replaceable or repairable without requiring separate hanger components, simplifying the repair process while maintaining frame protection.

Inventive Principle:

Principle #2Taking out (Extraction)

3Volume of moving object

If the rear derailleur is configured with linkages oriented at a slant for compact geometry, then the derailleur size is reduced and alignment with cassettes is improved, but the ease of operation for direct mounting without hanger becomes more difficult

Engineering Contradiction:

Improvederailleur compactnessVSAvoidalignment and mounting difficulty

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The patent employs asymmetric mounting arrangements where the mounting portions are positioned and oriented to accommodate the slanted linkage geometry. The first and second mounting portions are laterally spaced and oriented at specific angles to match the slanted pivot axes, enabling direct mounting while maintaining compact derailleur geometry.

Inventive Principle:

Principle #4Asymmetry

4Extent of automation

If motor or electrical components are incorporated into the rear derailleur, then wireless shifting and diagnostic capabilities are enabled, but the device complexity increases

Engineering Contradiction:

Improvewireless shifting capabilityVSAvoidintegration of electrical components

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The patent nests electrical components including a battery within the base member structure. The battery is positioned within the base member housing, and electrical connections are routed through the mounting portions to the moveable member, integrating power and control systems into the existing mechanical structure without adding external complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS20250319944A1Bicycle derailleur

Publication Date: 2025.10.16 SRAM LLC

AI summary

A bicycle derailleur includes a base member mountable to a bicycle frame and having first and second laterally spaced mounting portions defining first and second planes, and a space therebetween dimensioned to receive a portion of the bicycle frame. A first mounting arrangement defines a first pivot axis oriented at an acute angle relative to the first and second planes. A second mounting arrangement defines a second pivot axis parallel to the first pivot axis. A first link is pivotally connected to the first mounting arrangement and a second link is pivotally connected to the second mounting arrangement. A moveable member is pivotally connected to the first and second links. A battery may be mounted on the base member and electrically connected with a motor carried by the moveable member.