A broken chain on a ride means you're walking home unless you've got a chain tool that actually works. Plenty of compact chain tools fold under pressure or drift off-center mid-push, but Park Tool's CT-5 Mini Chain Tool avoids those problems with a fine-threaded handle and a hardened alloy steel pin that drives straight and stays aligned. The V-shaped handle gives you enough leverage to push rivets cleanly without the wrist fatigue you get from stubby multi-tool chain breakers, and the whole thing weighs 77 grams — light enough to forget it's in your saddlebag until you need it.

The CT-5 covers 5-speed through 12-speed derailleur chains, including SRAM T-Type, SRAM Flattop, and Shimano XTR 12-speed designs. It also works with many 1/8" single-speed chains, though it won't handle 3/16" or half-link single-speed chains. One important caveat for Campagnolo users: the CT-5 can remove and install Campagnolo 11-speed and 12-speed chain rivets, but it cannot peen them. Peening is required for proper Campagnolo chain installation, so you'd need a CT-4.3 or CT-6.3 for that final step.

The tool body includes 2 shelves — a lower shelf for driving out chain rivets and an upper shelf for loosening tight links after reassembly. Always use the lower shelf for rivet removal; the upper shelf is only for working out stiff links on older-style chains. The driving pin is replaceable (part number CTP), so when it eventually wears or breaks from use, you swap the pin instead of replacing the entire tool. Pin replacement requires a 7mm or 9/32" box end wrench and takes about 2 minutes. At 60mm x 55mm x 15mm, the CT-5 tucks into a saddlebag, jersey pocket, or tool roll without taking up meaningful space — and it's the kind of tool that earns its place the first time you actually need it trailside.