Jiankun positive and negative tooth optical disc

Release Time：

2026-04-05

Source：

Jiankun positive and negative tooth optical disc

Positive-and-negative teeth and conventional (traditional) teeth are the two core tooth-profile designs for bicycle chainrings, with the key difference lying in tooth thickness and engagement geometry—factors that directly determine the stability and efficiency of single-chainring systems.

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I. Key Structural Differences

1. Standard gears (traditional transmission gears)

Structure : Tooth profile Exact consistency in thickness, height, and width . To facilitate chain-based gear shifting, the tooth tips will be Shorten and bevel 。

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Principle : Only with the chain Internal link section Occlusion, External Link Section In a suspended state with a large gap.

Uses : for Multi-disc (2X/3X) variable-speed system Design, reliance Front derailleur Prevent chain drop.

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2. Positive and Negative Teeth

Structure : Straight teeth and Negative tooth Alternating arrangement 。

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Principle: The positive teeth precisely engage the outer links of the chain, while the negative teeth fit into the inner links, ensuring tight meshing across the entire pitch.

Application: Specifically designed for single-chainring (1X) systems, it prevents chain drop without the need for a front derailleur.

II. Comparison of Core Advantages

1. Anti-drop chain capability (the core advantage)

Standard tooth : When a single disc is used, the lateral clearance of the chain is large. Very easy to lose the chain , must rely on the front derailleur or chain guide.
Positive and negative teeth : Positive and negative teeth, just like a mortise-and-tenon joint. Lock down Chain, Significantly suppress lateral sway , it is also unlikely to come loose during severe turbulence or when jumping and landing.

2. Power Transmission Efficiency

Standard tooth : Large meshing clearance, easily causing Virtual position, skipped tooth , power interruption and inconsistent force application.

Positive and negative teeth : Large meshing area and tight fit, Zero backlash in power transmission , the stepping is more direct and uniform, with efficiency improved by approximately 18%。

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3. Structure and Maintenance

Standard tooth : Multi-disc systems have a complex architecture (front derailleur, cable housing), are heavy, and require tedious maintenance.

Positive and negative teeth ： Single-disk minimalist structure ， Weight loss (1–2 fewer chainrings, no front derailleur), Low failure rate , more resistant to mud and dirt.

4. Service Life

Standard tooth : Thin teeth and uneven stress distribution, Prone to wear and chipping 。

Positive and negative teeth : The straight teeth are thicker and more wear-resistant, Longer lifespan 。

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III. Summary of Applicable Scenarios

Select standard teeth ：

Still in use 2-chainring / 3-chainring , needs Front derailleur of the traditional model.

to Wide gear ratio There is extremely high demand (e.g., for long-distance mixed-road conditions).

Select positive and negative teeth ：

Mountain Bikes (XC/AM/Enduro) 、 Gravel (gravel bike) 、 Single-speed bikes, folding bikes, and children’s bikes 。

Pursuit Lightweight, concise, and highly stable ， Intense off-roading, maintenance-free 。

Jiankun Official Website: WWW.SZJIANKUN.COM

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