Pro Truing Stand

There is no truing without a reference, and the Pro Truing Stand is the reference. Mount the wheel on the stand, anchor the hub, spin it, and the calipers tell you what's true and what isn't. Mount it on a wobbly aluminum knock-off and you'll spend the rest of the session chasing your own equipment.

We rebuilt this stand from the base up after the previous generation taught us where the limits sat. The base is stronger so the calipers stay parallel under the load of a built wheel. The upright arms are longer to clear 29+ wheels, and the calipers were widened to match. Inside the upright, the bearings are now spring-loaded for tighter axle-adjust resolution and less frequent recalibration. The threads and springs throughout have been revised for smoother operation, and the caliper tips were reshaped so radial truing is a clean read instead of a guess.

The conical thru-axle adapters are included with the stand and held in place on the base by magnets when not in use. One size covers 12, 15, and 20 mm axles, and a bolt holds them firmly on the upright arms when the wheel is mounted. For permanent installation, the stand mounts to the bench through two 8 mm holes at 268 mm center-to-center; the included white high-gloss stickers can be applied to the base and caliper arm to give the rim contrast against the workshop's background.

Compatibility

• Wheels: 16 to 29+ inch, with or without tire.
• Hubs: solid axle, quick release, or thru-axle (12, 15, 20 mm) via the included adapters.
• Maximum hub width: 230 mm without adapters; 197 mm with adapters.
• Disc brake: accepts the Rotor Truing Gauge 1689.2 for in-stand rotor work.
• Special hubs: Cannondale Lefty Hub Adaptor 1689.6 covers Lefty and Supermax front hubs.

Specs

• Maximum arm opening: 230 mm without adapters; 197 mm with adapters.
• Bench mount: 8 mm holes at 268 mm center-to-center.
• Wheel range: 16 to 29+ inch.
• Thru-axle adapters: one-size-fits 12, 15, and 20 mm; magnetic stow on the base, bolt fix on the upright.
• Stickers: white high-gloss panels for caliper-and-base contrast; not pre-applied.
• Compatible accessories: Rotor Truing Gauge 1689.2, Wooden Base 1689.9, Cannondale Lefty Hub Adaptor 1689.6.

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 Truing Stand 1689 is the wheel-side counterpart to the chain-tool, brake-tool, and bottom-bracket families: every interface that touches a Unior bench can rely on the same construction discipline. The spring-loaded upright bearings, the revised threads and springs, and the magnetic adapter stow are all in-house decisions Unior made because our own mechanics work on these stands every day.

Pro tip from our mechanics

The stand is the heart of the bench, but a stand at rest is only as good as its calibration. After any move, drop, or hard knock, run the upright through its full range, then check zero against a known-true wheel. Both reads should sit dead-on in the lateral and radial calipers; if they don't, the stand wants a calibration pass. We cover the rest of the truing workflow (finding deviations, lateral and radial work, dish, tension balance) in the article we wrote alongside this rebuild: How to true a bike wheel →