Professional Chain Tool

A chain tool that doesn't draw attention to itself is the kind a shop keeps using. The Pro Chain Tool 1647/2ABI is the workshop screw-type that does the job and gets put away clean. No modular inserts, no system to learn; the chain plate sits in the support, the spindle tightens, the pin drives. That's the whole tool.

What the spindle does is what matters. Turn the handle, the pin advances against the chain pin, the chain pin moves through the outer plate. The Pro Chain Tool's spindle is precisely-made, so the pin advances on-axis through the entire stroke; off-center pin pushes are the most common chain-break failure, and the geometry of this tool keeps them from happening. The handle is heavy-duty double-component with grip texture that survives oily hands.

Compatibility

The 1647/2ABI covers most modern derailleur chains and also supports Campagnolo 11-speed. It does not support SRAM AXS flat-top chains; the flat-top plate geometry needs the dedicated insert that ships with the Master Chain Tool. For shops that service modern SRAM AXS bikes, the Master is the right pick; for shops that don't, the Pro Chain Tool is the cleaner tool to keep on the bench.

The driving pin is replaceable. Under normal use it'll outlast most home toolkits, but for benches that break chains daily we stock the matching Replacement Chain Tool Pins 1647.1/4A as a two-pack.

Specs

• Most 6-12 speed derailleur chains; also supports Campagnolo 11-speed
• 150 × 22 × 72 mm
• 175 g
• Pin diameter: 3.4 mm
• Material: premium flex plus carbon steel
• Surface finish: trivalent chrome plated
• Article number: 1647/2ABI-US

Note: SRAM AXS flat-top chains require the dedicated AXS support that ships with the Master Chain Tool 1647/2BBI; the 1647/2ABI does not include that insert.

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 Pro Chain Tool's premium flex plus carbon steel body and trivalent chrome plating are workshop-grade choices; the same finish that survives years of chain grease, brake dust, and the occasional bench coffee.

Pro tip from our mechanics

The pin drive itself is the easy part. The reinstall is where most chain breaks go wrong; getting the master link in the right way around, choosing peening over a quick-link for a Campagnolo chain, knowing whether a SRAM PowerLock is reusable on the chain you just pulled. Our chain-replacement guide maps those decisions and the routing details that make the difference between a clean swap and a chain that skips on the first ride: When and how to replace your chain →