Keeping a spare quick link in your saddle bag turns a ride-ending chain break into a five-minute trailside fix. The Shimano SM-CN910-12 2-Pack gives you two complete quick links for 12-speed Hyperglide+ chains, which means one for installation and one for emergencies or future maintenance. These are the same links that ship with Shimano's 12-speed chains from the factory.

The two-piece design snaps together by hand with forward pedal pressure, though dedicated chain pliers like Shimano's TL-CN10 make removal and installation cleaner. Directional arrows stamped into the plates indicate proper orientation since the ramped surfaces are designed to engage cassette and chainring teeth in a specific direction. The nickel plating makes them easy to spot during inspection, and the SIL-TEC surface treatment reduces friction at the connection point.

Shimano rates these as single-use links. Once you remove a quick link, replace it with a fresh one rather than reusing it. The locking mechanism can lose its secure engagement after repeated open-close cycles, and given the forces running through a chain under hard pedaling, a compromised link isn't worth the risk. The 2-pack makes this easy since you'll always have a replacement ready.... Read More