Quick-Connect Pivoting Chain Tensioner for Bicycle Trainers

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Solution Overview

Problem

Existing chain tensioners for bicycles and bicycle trainers are cumbersome and difficult to remove, as they constantly exert tension, making it challenging to mount or un-mount a bicycle or bicycle frame to a trainer, especially when using single-sprocket systems.

Innovation Solution

A chain tensioner system with a pulley arm that can pivot between open and closed positions, utilizing a tensioner element like a spring to maintain tension when closed and release it when open, allowing easy installation and removal of the bicycle from the trainer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional chain tensioner is used to maintain constant tension on the bicycle chain, then the chain remains securely engaged with the cassette gears, but the tensioner becomes difficult and cumbersome to remove when mounting or un-mounting the bicycle from the trainer

Engineering Contradiction:
Improvechain engagement reliabilityVSAvoidease of mounting/dismounting bicycle
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The chain tensioner transitions from a static constant-tension design to a dynamic design where the tensioner arm can pivot between positions. The spring-loaded mechanism automatically adjusts tension based on the arm's position, allowing the system to adapt between two states: engaged (providing tension) and disengaged (releasing tension for easy removal).

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The tensioner arm is divided into functional segments with a pivot point that allows independent movement. The arm can be positioned in distinct states (engaged/disengaged) rather than maintaining a fixed position, enabling the system to segment its operational modes for different phases of use.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a spring-loaded tensioner element is used to automatically maintain chain tension, then the chain remains taut during operation, but the tensioner creates friction and resistance when attempting to move or remove the bicycle

Engineering Contradiction:
Improvechain tension maintenanceVSAvoidfriction and resistance during movement
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The spring-loaded tensioner element works in conjunction with the movable arm to create a dynamic system. When the arm is in the engaged position, the spring maintains proper chain tension. When the arm pivots to the disengaged position, the spring's tension is released, eliminating friction and resistance during bicycle movement or removal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system prepares for potential removal by allowing the arm to be easily pivoted to a disengaged position before removal is attempted. This preliminary action releases the spring tension in advance, preventing the harmful friction and resistance that would otherwise occur during the removal process.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If the chain tensioner is designed to always exert tension force to keep the chain in place, then the chain remains securely engaged during cycling, but the tensioner becomes cumbersome and difficult to work with during installation and removal

Engineering Contradiction:
Improvechain security during cyclingVSAvoidcomplexity of installation and removal process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tensioner arm's ability to pivot between engaged and disengaged positions simplifies the installation and removal process. During cycling, the arm remains in the engaged position for reliable chain security. During installation or removal, the arm can be quickly pivoted to the disengaged position, eliminating the need to wrestle with a constantly tensioned mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of designing a tensioner that constantly fights against movement (as in traditional designs), this invention inverts the approach by allowing the tensioner to be easily disengaged when movement is needed. The system switches from a constant-resistance mode to a low-resistance mode during installation/removal, reversing the traditional behavior pattern.

Inventive Principle:
Principle #13The other way round (Inversion)

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 system provides reliable chain tension during use while enabling easy attachment and detachment of the bicycle, enhancing user convenience and reducing friction and resistance.

Implementation Method 1

a tensioner element (e.g., a spring) to which the pulley arm can be attached and from which the pulley arm can be detached

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a tensioner element for connecting the fixed tensioner arm with the pulley arm, the tensioner element for keeping the pulley arm in either the closed position or the open position under tension provided by the tensioner element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4592171A1Quick connect chain tensioner for bicycles and bicycle trainers
Publication Date: 2025.07.30 ZWIFT INC
  • EP4592171A1 patent drawingFigure 1~2
  • EP4592171A1 patent drawingFigure 3
  • EP4592171A1 patent drawingFigure 4

AI summary

There is disclosed a chain tensioner system including a pulley for rotatably engaging a bicycle chain or belt, a pulley arm, upon which the pulley is mounted, the pulley arm movable between a closed position and an open position, a fixed tensioner arm, engaged with the pulley arm, and a tensioner element for connecting the fixed tensioner arm with the pulley arm, the tensioner element for keeping the pulley arm in either the closed position or the open position under tension provided by the tensioner element when the pulley arm is in either the closed position or the open position.