Bicycle Disc Brake Hub Layout for Large Rotor Mounting
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Solution Overview
Problem
Existing bicycle hubs with disc brakes face challenges in securely fastening large-diameter brake discs, leading to increased brake forces, reduced lateral rigidity, and higher weights, which are exacerbated by the increasing weight of electric bicycles and demanding terrain.
Innovation Solution
The second spoke flange has a larger diameter than the first, with spoke retaining holes on an outer pitch circle and screw holes on a radially offset bolt circle, providing a larger diameter of at least 75 mm, and featuring base projections and recesses for improved brake force dissipation and direct brake feel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional machining methods are used to create flat mating surfaces on wheel hubs, then manufacturing simplicity is maintained, but runout and vibration occur due to insufficient contact area with the disc brake
Solution Approach 1:
The flat mating surface is segmented into multiple raised portions (protrusions) that contact the disc brake at discrete points. This segmentation increases the effective contact area and improves runout characteristics while maintaining a relatively simple hub structure that can be manufactured using conventional machining techniques.
Solution Approach 2:
Instead of providing a uniformly complex surface treatment across the entire hub, the invention applies localized raised portions only at the specific contact areas with the disc brake. This local quality approach improves brake contact stability precisely where needed while keeping the rest of the hub structure simple and easy to manufacture.
2Reliability
If flat mating surfaces are used on wheel hubs, then manufacturing is simple, but braking performance deteriorates due to runout and vibration
Solution Approach 1:
The mating surface is divided into multiple raised portions that can be machined as separate features using conventional techniques. This segmentation improves braking performance by ensuring stable contact with the disc brake while maintaining ease of manufacture through standard machining operations.
Solution Approach 2:
Instead of making the entire mating surface complex to improve contact, the invention inverts the approach by creating localized raised portions on an otherwise simple flat surface. This inversion achieves improved braking performance through targeted geometric modifications rather than comprehensive surface complexity.
3Reliability
If complex surface treatments are applied to wheel hubs, then runout is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The surface treatment is segmented into discrete raised portions rather than applying a complex continuous surface treatment. This segmentation reduces runout by creating stable contact points while keeping the surface treatment relatively simple and manufacturable using conventional machining methods.
Data Source
Figure 1
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AI summary
The invention relates to a hub for wheels of bicycles with disc brakes, having a hub shell 11 with first and second spoke flanges 13, 14 and a through hole 2. The spoke flanges 13, 14 each are provided with a plurality of spoke retaining holes 15, 16 arranged on a pitch circle around a wheel axle, and the second spoke flange 14 has a fastening device for a brake disc. In order to provide a hub enabling brake discs with large diameters to be fastened while avoiding high costs and rigidity problems, the second spoke flange 14 has a larger diameter than spoke flange 13, the retaining holes 16 on spoke flange 14 are arranged on an outer pitch circle 20 with larger radius than the holes 15 on spoke flange 13, and the screw holes 17 are arranged radially offset relative to the spoke retaining holes 16.