Bicycle Freewheel Coupling With Clearance Angle Against Pedal Kickback
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Solution Overview
Problem
Existing bicycle freewheel systems, particularly on full-suspension bicycles, experience pedal kickback due to chain reversal during suspension compression, leading to rider fatigue and performance issues, especially on rough terrain, and existing solutions require additional components or new hubs.
Innovation Solution
A bicycle component with a freewheel unit featuring a toothed gear assembly and rotating unit that allows for a defined clearance angle before torque transmission, using radial teeth and grooves for relative movement, enabling easy adjustment and retrofitting existing hubs without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional freewheel system is used, then the structure is simple, but pedal kickback occurs during suspension compression causing rider fatigue
Solution Approach 1:
The patent employs a dynamic freewheel mechanism where the toothed gear assembly can rotate relative to the rotating unit, creating a movable engagement system that adapts to different operational states (pedaling vs. suspension compression) to prevent harmful kickback forces
Solution Approach 2:
The invention changes the engagement parameter by introducing a defined clearance angle (at least 5°) between the toothed gear assembly and rotating unit, which modifies the torque transmission characteristics to eliminate pedal kickback while maintaining simple structure
2Object-affected harmful factors
If an adjustable mechanism is added to prevent pedal kickback, then pedal kickback is prevented, but the system becomes more complex and requires additional maintenance
Solution Approach 1:
The freewheel unit is designed to be a self-contained module that can be independently replaced, allowing the complex engagement mechanism to function as a self-service unit that maintains the entire hub assembly without requiring additional adjustment mechanisms or components
Solution Approach 2:
The patent segments the hub into modular components (rotating unit, toothed gear assembly, freewheel unit) that can be independently manufactured, assembled, and replaced, reducing overall system complexity while preventing pedal kickback
3Ease of operation
If a new hub design is implemented to adjust dead angle, then torque transmission control is improved, but it requires a completely new hub assembly
Solution Approach 1:
The patent merges the torque control function directly into the existing freewheel mechanism by integrating the movable toothed gear assembly with the rotating unit, eliminating the need for separate adjustment mechanisms or new hub designs
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
Prevents or significantly reduces pedal kickback by ensuring consistent torque transmission, enhancing rider comfort and performance without the need for additional components or new hubs, allowing for simple adjustments and reliable operation.
Implementation Method 1
The rotating unit and the toothed gear assembly are each designed as coupling components and each have radial teeth for engaging with each other
Implementation Method 2
The toothed gear assembly has a face toothing with axial engagement elements, which is suitable for engaging with corresponding engagement elements of another toothed gear assembly
Implementation Method 3
at least one preloading device, in particular in the form of a coil spring, which preloads the toothed gear assembly into the engaged position
Data Source
Figure 1~4
Figure 5a
Figure 5b~5e
AI summary
Bicycle component (80) for a bicycle (100) with a freewheel unit (9a, 9b) of a freewheel device (9), wherein the freewheel unit (9a, 9b) comprises a rotary unit (2d, 10d) and a toothed disc assembly (20, 30) that can be coupled to the rotary unit (2d, 10d). The toothed disc assembly (20, 30) comprises a face toothing (22, 32) with axial engagement elements (22e, 32e) which is suitable for engaging with corresponding engagement elements (32e, 22e) of another toothed disc assembly (30, 20). The toothed disc assembly (20, 30) and the rotary unit (2d, 10d) are each designed as coupling components (9c-9f) that can be coupled to each other and each have radial teeth (23, 33) for engaging with each other and are rotatable together about a central axis of rotation (5b).The rotary unit (2d, 10d) and the gear unit (20, 30) are movable in the circumferential direction relative to each other between a drive position (A) and a rest position (R), so that before the start of a torque transmission a coupling component (9c-9f) must first be rotated in the drive direction by a clearance angle (FW) of at least 5°, until a torque transmission can take place, if the two radial gears (33, 43) are previously in a rest position (R).