KMC MissingLink I Chain Connector - 6/7/8 Speed, Card of 2 Pair
The KMC MissingLink I is a reusable master link designed for 6, 7, and 8-speed chains. It provides a simple way to install, remove, or service compatible chains without pressing a traditional chain pin every time. This is the kind of small part every commuter, shop bench, and repair kit should have available.
Key Functional Details
- Reusable connecting link for 6, 7, and 8-speed chains
- 7.3mm pin length for correct drivetrain compatibility
- Compatible with KMC X8, Z8, Z7, Z50, and Z33 chains
- Also works with appropriate Shimano and SRAM 6/7/8-speed chains
- Quick chain connection without permanent chain pin installation
- Sold as card of 2 pair
- Grey finish
Technical Specifications
| Brand | KMC |
| Model | MissingLink I |
| Supplier Part # | ML57305 |
| Speed Compatibility | 6 / 7 / 8 Speed |
| Pin Width | 7.3mm |
| Use | Universal |
| Quantity | Card of 2 Pair |
| Color | Grey |
| UPC | 766759057305 |
| Country of Origin | Taiwan |
| Packaged Weight | 0.03 lbs |
Compatibility & Technical Notes
Good Fit: Riders using 6, 7, or 8-speed drivetrains who want easier chain service, emergency repair options, or cleaner drivetrain maintenance. Good for commuters, hybrids, older mountain bikes, comfort bikes, and many entry-level drivetrains.
Not A Fit: Not compatible with 9, 10, 11, or 12-speed chains. Not a fit for narrow modern road or MTB drivetrains requiring speed-specific master links. Do not assume all “quick links” are interchangeable across chain widths.
Master link sizing matters. This version uses a 7.3mm pin width specifically for wider 6/7/8-speed chains. Using the wrong link width can cause poor shifting, chain noise, or unsafe chain failure under load. Always match the link to the drivetrain speed first—not just the brand.
Service / Ownership Context
This is a strong low-cost add-on for routine service work. It makes chain cleaning easier because the chain can be removed and reinstalled quickly, and it is also useful as an emergency spare carried during rides. Shops should keep these on hand for older drivetrain repairs where replacing pressed chain pins repeatedly creates unnecessary wear.
Fit & Use Signals
- Best for commuters, hybrids, and older MTB drivetrains
- Good for routine chain cleaning and quick roadside repairs
- Useful as a spare master link in saddle bags or repair kits
- Excellent low-cost upsell during chain replacement service
- Not suitable for modern 11 or 12-speed performance drivetrains