Bicycle Chain Outer Link Plate Axial Recess Shifting
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Solution Overview
Problem
Conventional bicycle chains experience noise, skipping, slipping, and jarring during gear shifting from smaller to larger gears due to undesirable chain lift and contact with sprocket teeth, leading to delayed engagement and unpleasant shifting feel.
Innovation Solution
The design of an outer link plate with an axially recessed portion and chamfered edges that prevent the chain from lifting onto the crest of the sprocket tooth, allowing smooth engagement and disengagement by providing space for the tooth to travel upward without contact, and guiding the tooth outward if contact occurs, thus avoiding jarring shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional bicycle chains are used with larger sprockets having specially-profiled shifting teeth, then gear shifting capability is improved, but noise, skipping, slipping, and jarring occur during shifting
Solution Approach 1:
The outer link plate is designed with a non-uniform thickness profile, featuring a reduced thickness region (recess) at the intermediate portion and thicker regions at the end portions. This local variation in thickness creates a corresponding recess on the exterior surface that faces the sprocket tooth during shifting, allowing the tooth to travel upward into the recess without contacting the outer link plate, thereby eliminating chain lift and associated noise
Solution Approach 2:
The invention addresses the shifting problem by introducing a new dimensional feature - an axial recess created through non-uniform thickness variation in the outer link plate. This recess provides additional axial space for the sprocket tooth to travel upward during shifting, preventing contact with the outer link plate exterior surface and eliminating the chain lift phenomenon
2Adaptability or versatility
If conventional chains engage with larger sprockets, then gear ratio expansion is achieved, but delayed chain engagement and skipping occur
Solution Approach 1:
The reduced thickness region in the outer link plate is positioned in advance to face the sprocket tooth before engagement occurs. This preliminary positioning of the recess allows the tooth to smoothly travel upward into the recess during the shifting process, ensuring proper chain engagement with the larger sprocket and preventing skipping or delayed engagement
3Ease of manufacture
If outer link plates have uniform thickness, then manufacturing is simplified, but chain lift and contact with sprocket teeth occur during shifting
Solution Approach 1:
Instead of uniform thickness throughout the outer link plate, the invention applies local quality variation by creating a reduced thickness region at the intermediate portion while maintaining thicker regions at the end portions. This localized thickness variation is sufficient to create the necessary recess for preventing chain lift during shifting, while minimizing the overall complexity of manufacturing compared to completely non-uniform designs
Data Source
AI summary
An outer link plate for a bicycle chain is provided. The outer link plate has an interior surface configured to face another counterpart outer link plate in an assembled state and an exterior surface opposite to the interior surface. The outer link plate has an outer perimeter, and first and second end portions including respective first and second openings each having corresponding parallel center axes. An intermediate portion is provided interconnecting the first end portion and the second end portion. The intermediate portion has an axially recessed portion formed along the outer perimeter on the exterior surface, the intermediate portion having a pair of intermediate edges formed along the outer perimeter, the axially recessed portion being formed on at least one of the intermediate edges and including a chamfered portion connecting the at least one of the intermediate edges to the exterior surface of the outer link plate.