Speed Nipple Bit 2.5mm

Threading nipples onto spokes is the most time-consuming step of a wheel build. A 32-spoke wheel needs 32 nipples threaded down their spokes to the same depth before any tensioning happens; doing that by hand with a screwdriver takes ten or fifteen minutes per wheel. The Speed Nipple Bit lets you do it with a cordless screwdriver, which collapses that time to two or three minutes.

The 2.5 mm bit is sized for the standard slot-head internal spoke nipple; the most common nipple geometry in service across factory wheels, aftermarket wheel builds, and the bulk of the cycling industry. A small nub machined into the tip of the bit does two jobs: it keeps the bit centered in the nipple recess (so the driver doesn't walk off the nipple and skip across the rim), and it controls how far the nipple gets threaded down the spoke. When the nub touches the approaching spoke, the bit unseats from the nipple and the depth is set. Every nipple ends up at the same starting depth, which is the precondition for an even tensioning pass.

This is the workshop-efficiency tool for high-volume building. If you're building one wheel a season, a manual Nipple Driver 1751/2 is enough. If you're building a wheel a week (or a wheel a day, for a busy shop), the speed bit is the difference between a sustainable workflow and a frustrating one.

If your nipples have a 1.5 mm slot rather than 2.5 mm, the Speed Nipple Bit 1.5mm is the variant you need.

Compatibility

• Nipples: standard slot-head internal spoke nipples, 2.5 mm slot width.
• Drive: 1/4" hex shank (fits any standard cordless screwdriver, drill driver, or impact driver).
• Wheels: any wheelset with standard slot-head nipples.
• Companion: Speed Nipple Bit 1.5mm for smaller slot nipples.

Specs

• Tip: 2.5 mm slot, machined with depth-control nub.
• Drive: 1/4" hex shank.
• Compatible with cordless screwdrivers, drill drivers, and impact drivers.

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 Speed Nipple Bit is the production-build workshop tool; the bit you stock when you build wheels for a living. The depth-control nub is the in-house Unior engineering decision that distinguishes this bit from a generic flat screwdriver bit: most generic bits don't control depth, so the build still requires manual depth-check at every nipple. With the speed bit, the cordless driver does both jobs at once.

Pro tip from our mechanics

Run the cordless driver at low speed for the first quarter-turn of each nipple, then high speed once the nipple is fully engaged. Starting at high speed risks the bit walking off the nipple and stripping the recess; the slow-then-fast rhythm engages cleanly every time. The full wheel-building workflow is in How to true a bike wheel →