Solenoid Valve Seat Posts for Simpler Bicycle Height Adjustment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing height adjustable seat posts for bicycles, particularly dropper seat posts, are complex and expensive due to the use of battery-powered motors and complex gear systems, requiring position monitoring and manufacturing complexity.

Innovation Solution

The implementation of an electric solenoid to directly actuate the valve for seat post expansion or contraction, eliminating the need for position monitoring and reducing manufacturing complexity by utilizing a solenoid-operated valve system with a pneumatic chamber and pressurized gas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If battery-powered motors and complex gear systems are used for seat post height adjustment, then automatic position control is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveautomatic position controlVSAvoidcomplexity of motor and gear system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex motor and gear system from the dropper seat post, replacing it with a direct solenoid-actuated valve mechanism. This removes unnecessary components while retaining the essential height adjustment function, thereby reducing device complexity without sacrificing automation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical motor-gear system with an electromagnetic solenoid system that directly actuates the valve. This substitution eliminates the need for mechanical transmission components, reducing complexity while maintaining automated control through electrical actuation of the pneumatic chamber.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Extent of automation

If battery-powered motors and complex gear systems are used for seat post height adjustment, then automatic position control is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveautomatic position controlVSAvoidmanufacturing cost
Core Design Contradiction:
Extent of automationVSEase of manufacture

Solution Approach 1:

The patent removes expensive motor and gear components from the manufacturing bill of materials, replacing them with a simpler solenoid-actuated valve assembly. This extraction of unnecessary components directly reduces manufacturing cost while preserving the automated height adjustment capability through more economical means.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a cost-effective solenoid valve system that eliminates the need for expensive, precision-manufactured motor and gear assemblies. The simpler solenoid mechanism and direct-actuation design reduce manufacturing complexity and cost, making the automated dropper seat post more economically viable.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If position monitoring systems are implemented in dropper seat posts, then precise height control is achieved, but device complexity increases

Engineering Contradiction:
Improveheight control precisionVSAvoidcomplexity of position monitoring system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a self-regulating pneumatic system where the solenoid-actuated valve directly controls the pneumatic chamber pressure in response to rider weight and position. The system uses the rider's own weight as feedback, eliminating the need for separate position monitoring sensors and complex control electronics, thereby maintaining precision without increasing complexity.

Inventive Principle:
Principle #25Self-service

4Extent of automation

If complex gear systems and position monitoring are used, then automated height adjustment is achieved, but space requirements increase

Engineering Contradiction:
Improveautomated height adjustmentVSAvoidspace occupied by seat post mechanism
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The patent extracts and removes the space-consuming motor, gear train, and position monitoring components from the seat post assembly. The simplified solenoid-actuated valve mechanism occupies significantly less volume, enabling automated height adjustment in a more compact form factor that fits within standard seat post dimensions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a compact nested arrangement where the solenoid, valve, and pneumatic chamber are integrated within the existing seat post structure. The upper and lower tubes are telescopically arranged with the solenoid and valve components nested within the tube walls and chambers, minimizing the overall volume while maintaining automated functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution simplifies manufacturing, reduces costs, and minimizes space requirements while maintaining efficient seat height adjustment, offering a more cost-effective and less complex dropper seat post system.

Implementation Method 1

The seat post includes a solenoid to operate the valve between a closed state and an open state

Methodology Applied
Scientific EffectSolenoid: Solenoid

Implementation Method 2

The upper tube is sealed on both ends and forms a pneumatic chamber filled with a pressurized gas

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4371862B1Height adjustable seat posts for bicycles
Publication Date: 2025.09.10 SRAM LLC
  • EP4371862B1 patent drawingFigure 1
  • EP4371862B1 patent drawingFigure 2~3
  • EP4371862B1 patent drawingFigure 4

AI summary

Height adjustable seat posts for bicycles are described herein. An example height adjustable seat post (200) includes an upper tube (204) and a lower tube (202) configured in a telescopic arrangement. The height adjustable seat post also includes a shaft (508) coupled to the lower tube and extending into the upper tube and a piston assembly (510) coupled to the shaft and disposed in the upper tube. The piston assembly includes a piston (512) dividing the upper tube into a first chamber (516) and a second chamber (518). The first and second chambers are filled with fluid. The piston assembly includes a valve (520) operable between a closed state in which the fluid is blocked from flowing between the first and second chambers and an open state to enable the fluid to flow between the first and second chambers. The height adjustable seat post also includes a solenoid (522) to control the valve.