Bicycle Tire Shoulder Lug Geometry for Stone-Free Cornering Grip
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Solution Overview
Problem
Conventional bicycle tire stud profiles with cuts or notches suffer from reduced grip performance on loose and muddy surfaces due to stone entrapment and material blockage, which weakens the stud web and limits edge contribution to traction, especially on heavily loaded shoulder studs.
Innovation Solution
The introduction of wedge-shaped elevations on the top surface of shoulder studs, inclined at 5° to 30° in the circumferential direction, provides additional grip edges that are not impaired by stones and enhance traction during cornering on loose ground, with multiple elevations arranged at specific distances and dimensions to optimize grip and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cuts or notches are provided in the lug surface to increase grip edges, then grip performance is improved, but stones get caught in these cuts causing material blockage and weakening the lug structure
Solution Approach 1:
Instead of providing cuts or notches in the lug surface to create grip edges, the patent inverts the approach by providing elevations or protrusions on the lug surface. These elevations create additional grip edges without the harmful effect of stone entrapment, as they do not have recesses that can catch stones. The elevations are wedge-shaped and extend in the circumferential direction, providing multiple effective gripping edges that are not impaired by stones.
2Reliability
If multiple cuts are provided in the lug to increase edges, then grip is improved, but the material web between cuts deforms under transverse loads
Solution Approach 1:
The patent replaces cuts that weaken the lug structure with elevations that strengthen it. The wedge-shaped elevations are formed on the lug surface and extend in the circumferential direction, creating additional grip edges without compromising the material web between them. The elevations are integrated into the lug structure, providing multiple effective gripping edges while maintaining structural integrity under transverse loads.
3Reliability
If circumferential cuts are provided in the lug, then grip edges are increased, but the cuts close up under transverse loads reducing their effectiveness
Solution Approach 1:
Instead of using circumferential cuts that close up under load, the patent uses wedge-shaped elevations that remain effective under transverse loads. The elevations are oriented at an angle of 5° to 30° relative to the circumferential direction and extend in the circumferential direction, providing stable grip edges that do not deform or close up when lateral forces are applied during cornering on loose surfaces.
4Object-affected harmful factors
If the lug surface is made smooth to prevent stone entrapment, then stone blockage is reduced, but grip performance on loose surfaces deteriorates
Solution Approach 1:
The patent applies local quality by providing elevations only in specific regions of the lug surface where they are most effective for grip. The wedge-shaped elevations are positioned to extend in the circumferential direction and are arranged to provide multiple gripping edges without creating recesses that would trap stones. This localized structuring maintains grip performance while preventing stone entrapment.
Data Source
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AI summary
Bicycle tire (1) with a tread (2) having a tread base surface (2a) and a profile consisting of spaced-apart lugs, which include shoulder lugs (5) and central lugs (6), wherein the shoulder lugs (5) each have a top surface (8) running parallel or substantially parallel to the tread base surface (2a). On the top surface (8) of shoulder lugs (5) at least one wedge-shaped projection (12, 13) is formed, the top surface of which slopes down towards the outer edge of the tread and is elongated when viewed from above and in the circumferential direction of the tread.