Bicycle Head Tube Design for Lower Center of Gravity

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Solution Overview

Problem

Conventional bicycles with load beds positioned above the front wheel face stability and ride comfort issues due to elevated center of gravity, limited cargo space, and increased wind resistance, especially when loaded, and require raised handlebars for turns, compromising maneuverability.

Innovation Solution

A head tube design with larger diameter bearings positioned closer to the ends of the tubular section, reducing the vertical height while maintaining stability and durability, allowing the head tube to be placed beneath the load bed without intersecting it, thus lowering the center of gravity and enabling a larger front wheel for improved stability and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the load bed is positioned above the front wheel, then the bicycle can carry cargo, but the center of gravity is elevated causing stability issues

Engineering Contradiction:
Improvecargo carrying capacityVSAvoidbicycle stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The head tube is repositioned from a vertical orientation above the front wheel to a horizontal orientation beneath the load bed, effectively moving the steering mechanism to a different spatial dimension. This dimensional change allows the load bed to be positioned low on the frame while maintaining proper steering geometry, thereby keeping the center of gravity low for stability while still carrying cargo.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the head tube height is reduced to lower the center of gravity, then stability improves, but the bearing arrangement becomes constrained

Engineering Contradiction:
Improvebicycle stabilityVSAvoidbearing arrangement complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Instead of positioning bearings vertically along the head tube axis as in conventional designs, the invention inverts the arrangement by placing bearings horizontally at the ends of the tubular section. This inverted configuration allows the head tube to be shortened vertically while maintaining adequate bearing separation, thus lowering the center of gravity without compromising steering functionality.

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

Solution Approach 2:

The invention changes the orientation parameter of the bearings from vertical to horizontal, and repositions them from the center to the ends of the tubular section. This parameter change enables the head tube to achieve a compact vertical profile while maintaining the functional separation between bearings, resolving the conflict between height reduction and bearing arrangement.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If larger diameter bearings are used to improve durability, then the head tube height increases, but the center of gravity rises

Engineering Contradiction:
Improvehead tube durabilityVSAvoidcenter of gravity position
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention changes the spatial orientation parameter of the bearings from vertical to horizontal and repositions them to the ends of the tubular section. This allows larger diameter bearings to be accommodated in the horizontal dimension without increasing the vertical height of the head tube, thus maintaining durability while keeping the center of gravity low.

Inventive Principle:
Principle #35Parameter changes

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

This design enhances the stability and balance of the bicycle by lowering the center of gravity, reduces wind resistance, and allows for a more maneuverable load-carrying capacity without compromising ride comfort or increasing the bicycle's length.

Implementation Method 1

a first bearing having a first diameter, a second bearing having a second diameter, where the first bearing and/or the second bearing are adapted to provide a rotation around the central axis of the tube

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Data Source

PatentEP3183166B1Head tube for a bicycle
Publication Date: 2020.10.14 LARRY VS HARRY
  • EP3183166B1 patent drawingFigure 1~2
  • EP3183166B1 patent drawingFigure 3~4
  • EP3183166B1 patent drawingFigure 5~6

AI summary

A head tube (19) for a bicycle for providing a coupling between a bicycle frame and a wheel of the bicycle, wherein the head tube (19) comprises a central axis, a first bearing (25) having a first diameter, a second bearing (26) having a second diameter, the first bearing (25) and the second bearing (26) are adapted to provide a rotation of a steering fork assembly (20) around the central axis of the head tube (19), the first bearing (25) is arranged in a first position in a direction along the central axis, and the second bearing (26) is arranged in a second position in a direction along the central axis, and the size of the first and/or second diameter is larger than the distance from the first position of the first bearing (25) to the second position of the second bearing (26).