Bicycle Rear Sprocket Composite Material Weight Strength Trade-off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bicycle rear sprocket assemblies face challenges in balancing strength and weight, with existing designs often compromising on either aspect, and there is a need for improved engagement mechanisms between sprockets and the hub assembly for enhanced performance.
Innovation Solution
The bicycle rear sprocket assembly features a combination of non-metallic and metallic materials, with sprockets having integral chain-engagement structures and hub profiles, and intervening members that provide structural support and attachment via adhesive or integral molding, allowing for a truncated conical base portion and optimized torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If sprocket bodies are made of non-metallic material, then weight is reduced, but strength is compromised
Solution Approach 1:
The sprocket assembly uses a composite construction where non-metallic sprocket bodies are combined with metallic chain-engagement structures. The metallic structures are embedded within or attached to the non-metallic bodies, creating a composite component that leverages the weight advantages of non-metallic materials while maintaining the strength and wear resistance of metallic materials at critical engagement points.
2Strength
If chain-engagement structures are made of metallic material, then engagement strength is improved, but overall weight increases
Solution Approach 1:
The invention applies metallic materials selectively only at the chain-engagement structures where strength and wear resistance are critical, while the remainder of the sprocket body is made from non-metallic material. This localized application of metallic material minimizes weight increase while ensuring adequate strength at the specific locations where mechanical engagement occurs.
3Ease of manufacture
If sprockets are made as single unitary member, then manufacturing is simplified, but adaptability for different hub assemblies is reduced
Solution Approach 1:
The sprocket assembly is divided into distinct functional components: non-metallic sprocket bodies, metallic chain-engagement structures, and hub engagement profiles. These segmented components can be independently manufactured and then assembled together, allowing the hub engagement profiles to be varied for different bicycle hub assemblies while maintaining consistent chain-engagement functionality across the product line.
Data Source
AI summary
A bicycle rear sprocket assembly has a rotational center axis. The bicycle rear sprocket assembly comprises a first sprocket and a second sprocket. The first sprocket includes a first sprocket body and a first chain-engagement structure. The first sprocket body is made of a non-metallic material. The first chain-engagement structure is made of a metallic material and is configured to engage with a bicycle chain. The second sprocket includes a second sprocket body and a second chain-engagement structure. The second sprocket body is made of a non-metallic material and attached to the first sprocket body. The second chain-engagement structure is made of a metallic material and is configured to engage with the bicycle chain.