Chain Tool

Not every chain break needs a workshop tool. A home mechanic who replaces a chain twice a year, on a single bike, on a known drivetrain, doesn't need the modular insert system or the workshop-grade body. They need a chain tool that fits in a drawer, drives a pin cleanly when called on, and costs a fair price. The Chain Tool 1647HOBBY/4P is that tool.

What it shares with our workshop tools is the part that matters: the same 3.4 mm driving pin gauge as the Pro Chain Tool, in a smaller body. The spindle tightens the same way, the chain plate sits in the support the same way, the pin advances on-axis. What it doesn't share is the heavy-duty handle, the larger frame, or the spec range; this is corporate's deliberate home-user tool, slotted below the Pro and the Master.

Compatibility

Designed for 5- through 11-speed derailleur chains. That covers most home-shop drivetrains in service today: vintage road, mountain bikes through 11-speed, gravel bikes up through Shimano GRX 11 and SRAM Force 22. It does not support SRAM AXS flat-top chains, Campagnolo 11/12/13-speed peening, or 1/8″ singlespeed chains. For any of those, the Master Chain Tool 1647/2BBI is the right pick.

The driving pin on this tool is not replaceable; the spindle and pin are a single assembly designed for the use cycle of a home mechanic rather than the daily chain-breaks of a shop bench. If you find yourself wishing the pin came out, you've outgrown the tool, and the Pro Chain Tool 1647/2ABI is the next step.

Specs

• 5-11 speed derailleur chains
• 92 × 19.6 × 51 mm
• 120 g
• Pin diameter: 3.4 mm
• Comfortable dipped handles
• Article number: 1647HOBBY/4P-US

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The Hobby Chain Tool is the same engineering tradition applied at a smaller scale and a lower price point; the spindle threads and the driving-pin geometry come from the same workshop lineage as the Pro, but the body is sized for the toolbox of a home mechanic rather than the bench of a shop.

Pro tip from our mechanics

The first time you break a chain, the spindle does most of the work; the harder part is everything around it. Knowing when to break the chain (small-small on the bike, or off the drivetrain entirely on a bench), choosing the right link to break it at (avoid the master-link site if the chain has one), and where to leave a few millimeters of pin engaged for the reinstall. Our chain-replacement guide breaks down those calls and the differences between master-link and pin-pressed reinstalls: When and how to replace your chain →