Bicycle Wheel Pivot Positioning via Removable Adapters

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Solution Overview

Problem

Existing bicycle wheel positioning systems are inefficient for quickly switching between wheels of different diameters, requiring complex adapter systems and tools, and do not optimize dynamics when changing from 27.5" to 29" wheels without modifying the wheel axis.

Innovation Solution

A device comprising a rear stay with oblique and horizontal chainstays connected by triangular supports, featuring removable adapters with smooth holes for axial positioning of the derailleur hook, allowing two different axial arrangements of the wheel pivot without the need for screws or specific fixing holes, enabling quick and easy wheel diameter changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adapters with threaded holes and screws are used to fix the wheel axis, then the wheel can be securely mounted, but the time required for wheel changing increases and the operation becomes more complex

Engineering Contradiction:
Improvewheel mounting securityVSAvoidwheel changing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention extracts the threaded hole feature from the adapter design, eliminating the need for screws and threading operations. The adapter uses a simple hole through which the wheel axis passes, removing the time-consuming fastening operations while maintaining secure mounting through the axis passage itself.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of fixing the adapter to the dropout with screws through threaded holes, the invention inverts the approach by having the wheel axis itself serve as the positioning and securing element. The adapter is positioned on the dropout without fasteners, and the wheel axis passes through the adapter hole to complete the mounting, reversing the traditional fastening sequence.

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

2Adaptability or versatility

If multiple screws and adapters are used to enable wheel diameter changes, then wheel adaptability is improved, but the device complexity increases

Engineering Contradiction:
Improvewheel diameter compatibilityVSAvoidadapter system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adapter is designed as a universal component that works with both 27.5" and 29" wheels. The same adapter model can be used on either side of the rear stay, and the only requirement is that the wheel axis diameter matches the adapter hole. This eliminates the need for different adapter types for different wheel sizes, reducing device complexity while maintaining adaptability.

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

Solution Approach 2:

The invention segments the wheel mounting system into independent, simple components: the dropout, the adapter, and the wheel axis. Each component performs a single function, and they can be assembled or disassembled independently. This modular segmentation simplifies the overall system complexity compared to integrated fastening mechanisms.

Inventive Principle:
Principle #1Segmentation

3Reliability

If threaded holes are provided in the adapter for securing the wheel axis, then the connection is secure, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveconnection securityVSAvoidthreaded hole precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention removes the threaded hole feature from the adapter, replacing it with a simple through-hole. This eliminates the need for precise threading operations and reduces manufacturing precision requirements while maintaining secure connection through the wheel axis passage.

Inventive Principle:
Principle #2Taking out (Extraction)

4Measurement precision

If the derailleur hook is fixed rigidly to the dropout, then the positioning is precise, but the risk of breakage upon impact increases

Engineering Contradiction:
Improvederailleur positioning accuracyVSAvoidimpact breakage risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The derailleur hook is designed to rotate freely on the wheel axis while maintaining its positioning function. This dynamic capability allows the hook to absorb impact forces through rotation rather than rigid transmission, reducing breakage risk while preserving positioning accuracy during normal operation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3904193B1Device for the selective positioning of the pivot of a wheel
Publication Date: 2024.08.28 FANTIC MOTOR SPA
  • EP3904193B1 patent drawingFigure 1
  • EP3904193B1 patent drawingFigure 2
  • EP3904193B1 patent drawingFigure 3~4

AI summary

A device (1) for the selective positioning of the pivot (100) of a wheel of a bicycle comprising a frame composed of a rear stay (2) provided with a first pair of first oblique rear chainstays (3a, 3b) which are each connected, respectively by means of a triangular support (5a, 5b), to a second pair of two second horizontal rear chainstays (4a, 4b), a derailleur hook (14) being associable with the first chainstays (3a) and second chainstays (4a). First external seats (8) and second internal seats (9) are provided at the first internal surface (7b) and at the first external surface (7a) of the support (5a) for the axial and removable positioning respectively of a first external adapter (10a) and of a second internal adapter (10b). The first external adapter (10a) and the second internal adapter (10b) have respectively a second hole (12) and a third hole (23), both of which are smooth and are adapted to determine two different axial arrangements of the derailleur hook (14) and consequently of the pivot (100) of the wheel with respect to the two first and second chainstays (3a, 4a) and are adapted to keep the derailleur hook (14) locked in clockwise rotation and free to rotate counterclockwise only through a chosen arc.