Double Sided Spoke Wrench 4.3mm x 4.4mm

The 4.3 mm and 4.4 mm nipple sizes sit at the upper end of standard MTB and tandem builds. Together on one combination-wrench-style body, the 4.3/4.4 mm variant covers both sizes from a single tool; the workshop-economy version of having two dedicated wrenches on the bench.

For a workshop servicing wheels at the heavier end of the spoke-load range (downhill MTB, fat-bike builds, some tandem rims, some industrial-spec wheelchair wheels), this is the spoke wrench that lives in the truing-stand drawer. The four-flat engagement on each side is sized to the published nipple tolerance, and the combination-wrench form factor means a single drawer slot covers two sizes.

Across the wheelbuilding catalog, the three double-sided wrench configurations are: this 4.3/4.4 mm variant for upper-MTB builds, the 4.0/4.4 mm variant for standard MTB and heavier road, and the 3.3/3.45 mm variant for road and gravel. Together they cover the modern wheel range from three tools.

Compatibility

• Nipple sizes: 4.3 mm (one side), 4.4 mm (other side).
• Engagement: four-flat on both sides.
• Wheels: upper-MTB builds (downhill, fat-bike, heavier-spec wheel-chair, some tandem rims).

Specs

• Two nipple sizes on a single combination-wrench-style body.
• Plastic-dipped handle for grip.
• Companion sizes: 3.3 x 3.45 mm and 4.0 x 4.4 mm.

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 4.3/4.4 mm double-sided wrench is a niche-but-essential tool for the workshops that service heavier-rim builds; if you've never seen a 4.4 mm nipple in your service queue, this isn't the wrench you need, but if you've ever fought a 4.4 mm nipple with a too-small wrench, you understand why the dedicated tool exists.

Pro tip from our mechanics

A 4.3 mm wrench is close enough to 4.4 mm that a tired mechanic at the end of a long shift can mix them up. The result is a slightly-loose wrench that will round the larger nipple. Same trick as the 4.0/4.4 wrench: tape one end at the start of the build, leave the other bare; the visual cue keeps the size-selection decision separate from the size-stamping decision. The full wheel-truing workflow is in How to true a bike wheel →