Adjustable Bicycle Frame Bottom Bracket Geometry
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Solution Overview
Problem
Existing bicycle frames struggle to adapt geometry for varying ride conditions, such as uphill and downhill terrains, due to limited adjustability of the rear suspension and bottom bracket position, leading to reduced rigidity and stability, especially during pedaling.
Innovation Solution
A bicycle frame design featuring a front triangle and rear frame with a mobile body that can rotate or slide relative to the front triangle, allowing the bottom bracket and rear frame to change position, thereby adjusting the bicycle geometry for different riding conditions, facilitated by an actuator and blocking mechanism for remote control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the bicycle frame uses a fixed geometry design, then the structural rigidity and stability are maintained, but the adaptability to varying terrain conditions (uphill/downhill) deteriorates
Solution Approach 1:
The patent applies the dynamics principle by making the bottom bracket position adjustable rather than fixed. The bottom bracket is mounted on a movable carrier that can change its position relative to the front triangle, allowing the bicycle geometry to adapt dynamically between uphill and downhill configurations. This resolves the contradiction by enabling the structure to maintain rigidity in each fixed position while adapting to different terrain conditions.
Solution Approach 2:
The patent changes the positional parameter of the bottom bracket to adapt the bicycle geometry. By varying the bottom bracket's position (horizontal and vertical displacement) through the movable carrier mechanism, the bicycle can optimize its geometry for different riding conditions. This parameter change allows the same frame to provide both uphill efficiency and downhill stability without compromising structural integrity.
2Adaptability or versatility
If the bottom bracket position is made adjustable for different terrains, then the adaptability to uphill and downhill conditions is improved, but the structural rigidity and stability during pedaling deteriorates
Solution Approach 1:
The movable carrier with blocking mechanism allows the bottom bracket position to be dynamically adjusted between predetermined positions. When blocked in a position, the structure maintains sufficient rigidity for pedaling. The blocking mechanism ensures that once a position is selected, the bottom bracket remains stable and rigid during pedaling operations, resolving the contradiction between adjustability and structural strength.
Solution Approach 2:
The blocking mechanism is designed to automatically secure the bottom bracket in predetermined positions during pedaling. The carrier can be freely moved for adjustment but self-locks when reaching predetermined positions, providing automatic stabilization. This self-service feature ensures structural rigidity is maintained during pedaling without requiring continuous active control, resolving the strength concern.
3Ease of operation
If a movable body with blocking mechanism is introduced to adjust bottom bracket position, then the adaptability and ease of operation are improved, but the device complexity increases
Solution Approach 1:
The bottom bracket assembly is segmented into the bottom bracket itself and the movable carrier that holds it. This segmentation allows the carrier to be independently moved and blocked at different positions while keeping the bottom bracket functional components separate. The segmentation simplifies the adjustment mechanism by isolating the mobility function to the carrier, reducing overall device complexity while maintaining ease of operation.
Solution Approach 2:
The movable carrier acts as an intermediary between the fixed front triangle and the bottom bracket. It provides the mobility function while allowing the bottom bracket to remain relatively simple in design. The carrier mediates the complexity by concentrating the adjustment mechanism in one component, making the overall system easier to operate without requiring complex modifications to the bottom bracket itself.
4Adaptability or versatility
If the bottom bracket position is fixed, then the manufacturing precision and ease of manufacture are maintained, but the adaptability to different riding conditions deteriorates
Solution Approach 1:
The carrier is designed with predetermined blocking positions that are established during manufacturing. These predetermined positions are pre-calculated and pre-positioned in the frame structure, allowing the bottom bracket to be adjusted to optimal positions for different terrains. The preliminary action of pre-positioning these blocking points simplifies manufacturing by providing fixed reference points, while still enabling post-manufacturing adaptability through the adjustment mechanism.
Solution Approach 2:
The movable carrier with blocking mechanism serves multiple functions: it provides adaptability to different terrains, maintains structural rigidity when blocked, and simplifies manufacturing by using predetermined positions. This multi-functional design allows a single component to address both manufacturing simplicity and riding condition adaptability, resolving the contradiction between ease of manufacture and versatility.
Data Source
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AI summary
A bicycle frame (100) comprising: - a front triangle (110); - a rear frame (130) articulated to the front triangle (110); - a body (21) associated to the front triangle (110) and mobile with respect thereto; - a bottom bracket (22) rotatably associated to the body (21) about a first rotation axis (B); wherein the rear frame (130) is articulated to the body (21) about a second rotation axis (C) parallel to the first rotation axis (B).