Derivleur Rotation Angle Indicator for Chain Gap Setting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Derailleurs with non-sloped or lightly sloped parallelograms in wide-range single-speed mountain bikes are sensitive to chain gap settings due to increased dependency on chain length and frame suspension kinematics, making precise chain gap adjustment challenging and prone to shifting issues.
Innovation Solution
A derailleur with a B-knuckle assembly, P-knuckle assembly, and a parallelogram assembly, equipped with a rotation angle detection device that indicates the angle between the P-knuckle and cage assemblies, allowing for convenient and accurate chain gap setting without requiring direct measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a parallelogram with little or no slant is used in the derailleur, then operating forces are reduced when shifting, but the chain gap becomes highly sensitive to chain length, frame suspension kinematics, and chain wear
Solution Approach 1:
The patent implements a feedback mechanism by providing visual markings (such as colored rings or indicators) on the derailleur body that show the current chain gap status. These markings allow the user to see whether the chain gap is within the acceptable range, providing immediate feedback on the effectiveness of adjustments and enabling precise tuning to compensate for sensitivity to chain wear and suspension movement.
2Reliability
If the distance between the upper chain guide pulley and P-knuckle pivot axis is increased, then the chain gap can be maintained across different transmission ratios, but the system becomes more sensitive to chain length and suspension kinematics
Solution Approach 1:
The patent replaces complex mechanical measurement and adjustment procedures with a simple visual indication system. Instead of requiring precise mechanical measurements of chain gap distances and angles, the system uses visual markings that automatically indicate when the chain gap is correct, substituting a simple visual detection mechanism for complex mechanical tuning procedures.
3Reliability
If conventional derailleurs with slanted parallelograms are used, then the chain gap is less sensitive to chain wear and suspension movement, but operating forces increase during shifting
Solution Approach 1:
The patent changes the geometric parameters of the parallelogram mechanism, specifically using a parallelogram with little or no slant (nearly vertical orientation) compared to conventional slanted parallelograms. This parameter change reduces the operating forces required for shifting while the visual indication system compensates for the increased sensitivity to chain wear and suspension kinematics.
Data Source
AI summary
The disclosure relates to a derailleur for a bicycle, comprising a B-knuckle assembly which is designed for mounting on the bicycle frame, a P-knuckle assembly, a parallelogram assembly via which the B-knuckle assembly and the P-knuckle assembly are movably connected to one another, a cage assembly in which a chain guide pulley and a chain tension pulley are rotatably held, where the cage assembly is mounted on the P-knuckle assembly so as to be rotatable about a P axis, and an rotation angle detection device which is designed to detect and/or display an angle of rotation between the P-knuckle assembly and the cage assembly.