As competition intensifies in the mid- to high-end elliptical trainer segment, stride adaptability has become a key differentiator among leading global brands. A recent patent filing by Johnson Health Tech (Shanghai) introduces a motor-driven mechanism designed to automatically adjust stride length, offering a new structural approach within the variable-stride category.

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Patent Overview

• Patent title: Elliptical Trainer with Automatically Adjustable Stride

• Applicant: Johnson Health Tech (Shanghai) Co., Ltd.

• Application number: 202511484579.8

• Publication number: CN121130379A

• Application date: October 17, 2025

• Publication date: December 16, 2025

The invention proposes a motor-assisted linkage system capable of automatically adjusting stride length, enabling a single machine to accommodate users of different heights and exercise preferences.

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Industry Background: Fixed Stride as a Long-Standing Limitation

Traditional elliptical trainers rely on fixed linkage geometry, meaning the stride length is predetermined by the crank and linkage configuration. According to the patent background section, this design forces users to adapt to a single motion path, which may not be suitable for very tall or short individuals.

As global brands continue to compete in the premium cardio segment, adjustable stride systems have emerged as a major selling point, particularly in commercial and connected fitness equipment.

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Core Technical Concept

The patented design is based on a four-bar linkage elliptical structure, combined with an electrically driven adjustment mechanism.

Main system components

The elliptical trainer consists of three primary subsystems:

1. Frame structure

2. Linkage assembly (four-bar mechanism)

3. Resistance transmission system

The linkage assembly includes:

• Crank link

• Rocker arm

• Swing arm

• Lower handlebar

• Pedal

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Motor-Driven Stride Adjustment Mechanism

The key innovation lies in a trajectory adjustment system installed on the lower handlebar, consisting of:

• A lead screw

• A drive motor (lifting motor)

Working principle

1. The motor drives the lead screw.

2. The crank link moves along the screw.

3. The effective length of the lower handlebar changes.

4. The initial height of the swing arm shifts.

5. The pedal trajectory changes.

6. The stride length is automatically adjusted.

In practical terms:

• When the crank link moves downward on the screw, stride becomes shorter.

• When it moves upward, stride becomes longer.

This allows the machine to provide a broader adjustment range and more precise stride control compared with fixed-geometry designs.

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Resistance Transmission Layout

The trainer uses a two-stage belt transmission system:

Pedal motion

→ Four-bar linkage

→ Crank

→ Main shaft

→ First belt stage

→ Second belt stage

→ Resistance wheel

Resistance is then transmitted back to the pedals through the linkage.

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Positioning Within Global Variable-Stride Technologies

Across the industry, variable-stride systems generally fall into three technical routes:

1. User-adaptive stride (Precor AMT-type systems)

• Stride length changes dynamically based on user motion.

• No motor-driven geometry adjustment.

2. Mechanically adjustable stride

• Pre-set linkage geometry or adjustable pivot points.

• Often manual or synchronized mechanical adjustment.

3. Motor-driven active stride adjustment

(This patent’s category)

• Motor adjusts linkage geometry.

• Allows precise, programmable stride settings.

• Enables integration with digital programs and user profiles.

The Johnson patent clearly falls into the third category, which is typically associated with higher-end commercial or connected fitness equipment.

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Industry Takeaway

This patent reflects a broader trend in the cardio equipment market:

• Moving from fixed-geometry machines

→ toward adaptive, user-specific motion systems.

By integrating a motor-driven variable-geometry linkage into a conventional four-bar elliptical structure, the design offers a relatively straightforward path to adjustable stride functionality without completely redesigning the core drivetrain.

For manufacturers, this approach may represent a cost-balanced solution between traditional fixed-stride ellipticals and more complex adaptive motion platforms.

Disclaimer

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