Composite Bicycle Wheel Spoke Tension via Movable Flange

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Solution Overview

Problem

Existing methods for manufacturing composite bicycle wheels face challenges with tight manufacturing tolerances and difficulty in achieving high spoke tension, which affects the wheel's rigidity and runout/roundness.

Innovation Solution

A method involving a composite rim and spokes with a hub assembly where spokes are distributed in two layers, with one flange mounted radially on the hub body and the other movable, allowing for radial play adjustment to induce higher spoke tension without individual tension adjustment means, utilizing an asymmetrical rim section to enhance tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If spokes are assembled to fixed flanges without radial play, then manufacturing precision is improved, but device complexity increases and ease of manufacture deteriorates

Engineering Contradiction:
Improvewheel runout and roundness tolerancesVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies the dynamics principle by making one flange movable along the hub body with radial play, allowing the assembly structure to adapt during manufacturing. The movable flange can be positioned at different radial distances from the hub axis, enabling adjustment of spoke tension without requiring precise fixed positioning, thus resolving the contradiction between manufacturing precision and ease of manufacture.

Inventive Principle:
Principle #15Dynamics

2Force

If individual tension adjustment means are added to spokes, then spoke tension is improved, but device complexity increases

Engineering Contradiction:
Improvespoke tensionVSAvoidindividual tension adjustment means
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent extracts the tension adjustment function from the individual spoke level and relocates it to the flange assembly level. Instead of adding adjustment mechanisms to each spoke, the invention uses a single movable flange that, when positioned at different radial distances, simultaneously adjusts the tension of multiple spokes. This eliminates complex individual adjustment means while achieving the desired spoke tension.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The movable flange serves multiple functions: it acts as both a structural support element and a tension adjustment mechanism. By moving the flange radially, the system can adjust spoke tension for the entire wheel without requiring separate adjustment mechanisms for each spoke, demonstrating multi-functionality that reduces overall device complexity.

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

3Force

If asymmetric rim section is used, then spoke tension is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvespoke tensionVSAvoidrim section symmetry
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent deliberately introduces asymmetry in the rim section design to optimize spoke tension distribution. The asymmetric cross-section allows the rim to better accommodate the tension forces generated by the movable flange configuration, converting what would normally be a precision constraint into a functional advantage for achieving higher and more uniform spoke tension.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP1764234B1Production method for a wheel made of composite material and wheel made of composite material
Publication Date: 2012.06.20 MAVIC SA
  • EP1764234B1 patent drawingFigure 1
  • EP1764234B1 patent drawingFigure 2~3
  • EP1764234B1 patent drawingFigure 4

AI summary

The procedure, using spokes (16, 20) in two layers extending from one side of the wheel rim (3) to the other and connected in the middle to the hub (14), consists of fitting one set of spokes to a fixed flange (14b) on the hub and the other set to an adjustable flange (18) which is fastened to the hub by adhesive. The wheel is assembled on a frame with a cradle that supports the rim and has a moving plate to support the hub, adjusted lengthwise in alignment with the hub's axis.