Segmented Bicycle Chain Guard for Rear Suspension Movement

Solution Overview

Problem

Conventional chain guards on bicycles with rear suspension fail to effectively cover the drive chain when the rear wheel compresses or extends, leading to inadequate protection against soiling of clothing.

Innovation Solution

A chain guard divided into two independently attachable sub-sections, one attached to the frame triangle and the other to the swingarm, allowing the guard to adjust its position relative to the drive chain's movement due to suspension compression or rebound.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional fixed chain guard is used on a bicycle with rear suspension, then the chain guard structure is simple and easy to manufacture, but the chain guard fails to follow the drive chain when suspension compresses or extends, resulting in inadequate coverage

Engineering Contradiction:

Improvechain coverage effectivenessVSAvoidchain guard structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The chain guard is divided into multiple independent sections that can be attached at different locations on the bicycle frame. Each section can move independently relative to the others, allowing the overall structure to adapt to chain position changes while maintaining coverage effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The chain guard transitions from a fixed rigid structure to a dynamic articulated structure. The sections are connected in a way that allows relative movement, enabling the chain guard to follow the drive chain's position changes during suspension compression and extension while maintaining continuous coverage.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the chain guard is made as a single fixed piece, then the manufacturing process is simple, but the chain guard cannot adapt to position changes of the drive chain caused by suspension movement

Engineering Contradiction:

Improveadaptation to chain position changesVSAvoidmanufacturing complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The chain guard is divided into multiple independent sections that can be attached at different locations on the bicycle frame. Each section can move independently relative to the others, allowing the overall structure to adapt to chain position changes while maintaining coverage effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The articulated chain guard design provides multi-functionality: it maintains chain coverage during suspension movement, allows for easier installation and adjustment, and can be configured in different arrangements depending on the specific bicycle application.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If a fixed chain guard is used, then the structure is stable and simple, but clothing protection is insufficient when the rear wheel suspension moves

Engineering Contradiction:

Improveclothing soiling preventionVSAvoidchain guard construction

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The chain guard transitions from a fixed rigid structure to a dynamic articulated structure. The sections are connected in a way that allows relative movement, enabling the chain guard to follow the drive chain's position changes during suspension compression and extension while maintaining continuous coverage.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The chain guard is divided into multiple independent sections that can be attached at different locations on the bicycle frame. Each section can move independently relative to the others, allowing the overall structure to adapt to chain position changes while maintaining coverage effectiveness.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4647329A1Chain case for a bicycle, in particular for a bicycle with at least one rear wheel suspension, and bicycle

Publication Date: 2025.11.12 KALKHOFF WERKE

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AI summary

A chain guard for a bicycle, particularly for a bicycle with at least rear suspension, preferably for a full-suspension bicycle, with a housing body that at least partially follows the path of the bicycle's drive chain, is designed to consist of at least two sub-bodies, each independently attached to the bicycle. This chain guard is suitable for a bicycle with a sprung rear wheel.