Chainring PCB Power Meter for Precise Strain Sensor Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The installation, positioning, and coupling of strain measurement devices in bicycle power meters are tedious and costly, requiring significant effort and separate circuitry construction.

Innovation Solution

Integrating strain measurement devices with the operational circuitry of a bicycle power meter, such as a printed circuit board, forming a unitary single piece with the chainring structure, allowing for easier alignment and reduced resource intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strain measurement devices are individually positioned and manually attached to bicycle components, then measurement precision is achieved, but device complexity and installation difficulty increase significantly

Engineering Contradiction:
Improvepower measurement accuracyVSAvoidinstallation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the strain measurement devices with the operational circuitry into a single integrated power meter unit. The strain measurement devices are mounted on a common substrate (printed circuit board) along with the processing circuits, eliminating the need for separate attachment of individual components. This integration reduces installation complexity while maintaining measurement precision through factory-preconfigured sensor-circuitry alignment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The strain measurement devices and circuitry are pre-assembled and pre-positioned on the substrate during manufacturing. This preliminary assembly ensures precise alignment and configuration before the entire unit is installed on the bicycle component, significantly reducing on-site installation difficulty while preserving measurement accuracy.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If separate circuitry construction is used for strain measurement devices, then functional reliability is achieved, but manufacturing cost and time consumption increase

Engineering Contradiction:
Improvepower meter reliabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The operational circuitry and strain measurement devices are merged into a single integrated assembly mounted on a common substrate. This unified construction reduces the number of separate manufacturing steps, lowers assembly complexity, and decreases production time while maintaining system reliability through standardized integrated circuit design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The substrate serves multiple functions simultaneously: it provides mechanical support for the strain measurement devices, electrical connections for signal transmission, and mounting structure for the operational circuitry. This multi-functionality reduces the number of separate components needed, simplifying manufacturing while ensuring reliable electrical and mechanical connections.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple separate components are assembled to form the power meter, then functional versatility is achieved, but installation time and resource intensity increase

Engineering Contradiction:
Improvepower meter functionalityVSAvoidinstallation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The power meter integrates strain measurement devices, operational circuitry, and processing functions into a single pre-assembled unit. This consolidation maintains full functional versatility while reducing installation to a single component mounting operation, dramatically cutting installation time and resource requirements.

Inventive Principle:
Principle #5Merging (Combining)

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

Facilitates less expensive and efficient construction and positioning of power meter components, enabling accurate power measurement with reduced effort.

Implementation Method 1

strain measurement devices, such as strain gauges, to measure deflection and/or deformation of a bicycle component during use to establish the amount of power

Methodology Applied
Scientific EffectStrain measurement: Piezoresistive Effect

Data Source

PatentEP3514048B1Bicycle power meter
Publication Date: 2025.12.03 SRAM LLC
  • EP3514048B1 patent drawingFigure 1A
  • EP3514048B1 patent drawingFigure 1B
  • EP3514048B1 patent drawingFigure 2

AI summary

A power meter (200) for a bicycle (100) includes a body (401) having a torque input section (225, 325) and a torque output section (222, 322), the body (401) configured to transmit power between the torque input section (225, 325) and the torque output section (222, 322). The power meter (200) also includes a printed circuit board ("PCB") having a substrate (252) and at least one strain measurement device (260) which may be attached to the PCB. The power meter (200) may be integrally constructed with a chainring construction.