Square taper cranks are not dead. ISIS is back in places it had been written out of, gravel and mid-tier road both. If a crank is sitting on a tapered or splined spindle, it isn't coming off without a puller, and the same puller has to handle both interfaces if it's going to live on the bench rather than in a drawer. The 1661/4 is that bench tool. The body is drop-forged from premium flex plus carbon steel, hardened and tempered, then chrome-plated to ISO 1456:2009; the same construction conventions Unior uses across the catalogue's load-bearing pliers and pullers. Square-taper face on one side, included splined adapter for ISIS and Octalink on the other; one body, two crank interfaces. How it's used The puller threads into the crank arm's puller threads (8 mm hex bolts on splined cranks, 14 mm or 15 mm bolts on square taper come off first). The centre rod then drives against the spindle and pushes the crank arm outward along the spindle axis. The crank releases with a pop. For square taper, fit the square face directly against the spindle nose; for ISIS or Octalink, slide the included splined adapter over the centre rod first to keep the rod from punching into the splined hollow at the spindle end. The 1661/4's centre rod takes a 14 mm hex socket on the wrench-end face; the same socket used to remove most splined-crank centre bolts before pulling the crank itself. One tool covers the bolt-removal step and the crank-pull step; you don't need a second wrench in the kit for the bolt. The wrench flats on the puller body take a 17 mm open-end wrench. An adjustable wrench works in a pinch, but a properly-sized 17 mm gives the cleanest hold on stuck cranks where every bit of leverage matters. Compatibility All current and legacy square-taper cranks (Shimano, FSA, Race Face, Truvativ square-taper, generic JIS and ISO tapers). ISIS Drive (Truvativ, Race Face, FSA, Stronglight) using the included splined adapter. Shimano Octalink V1 and V2 using the same splined adapter. Compatible with M22 × 1.0 puller threads (the industry-standard puller thread for square taper and splined cranks). Specs Material: premium flex plus carbon steel, drop-forged, hardened and tempered Surface finish: chrome-plated to ISO 1456:2009 Wrench flats: 17 mm Centre socket: 14 mm hex Puller thread: M22 × 1.0 Includes: splined adapter for ISIS and Octalink (pre-installed on the centre rod for storage) Built in Zreče Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The 1661/4's drop-forged construction is what holds the puller threads true under the load it takes to move a stuck crank; lower-grade pullers stretch in the body before they break the crank loose, then strip when they spring back. Pro tip from our mechanics If the puller threads in the crank arm have already started to give up, the centre rod skates and the puller spins in place without moving the crank. Two recoveries are possible: clean the spindle face under the rod (most slipping cases are dirty steel under the rod, not stripped threads), or step up to the 1662/4 Square Taper Crank Puller, whose tapered puller threads grip in places a straight-thread puller can't. For the full crank-removal decision tree by interface (square taper, splined, Hollowtech II, DUB), plus the cap-tool gotchas that strip drive holes: How to remove a crankset →.
