Bottom Bracket Facing Tool

A bottom bracket shell faces two ways at once. The drive-side face and the non-drive-side face have to be parallel to each other, perpendicular to the shell's bore, and clean enough to clamp a cup against without rocking. A factory shell that doesn't meet those conditions sends every drop of crank force through a cup that's sitting slightly cocked, and the bearings wear unevenly from the first ride. The Bottom Bracket Facing Tool 1699 is the bench tool that brings the faces back to parallel-and-square; the same tool that the Tech Tips walk-through demonstrates step by step.

What the tool does

The 1699 mounts to the shell through the bore and presents a rotating cutter to each face. The cutter trims a fine pass off the shell metal until the face is square to the bore the tool itself registers on. Both faces get cut in the same setup, which is what makes them parallel; the tool's geometry is the reference, and the parallelism comes from the tool, not from the original shell condition.

The 1699 is part of Unior's modular frame-prep series. It shares its handle with the Head Tube Reamer and Facer 1694, the BB taps (1697 BSA, 1698 Italian, T47), and the other modular frame-prep tools. A workshop running the full series carries one handle and a kit of cutters and guides, not a separate handle per operation.

Compatibility

The 1699 is the shell-side facing tool. Pair it with the right guide for the BB shell standard:

• BSA (1.37″ × 24 TPI): BSA Bottom Bracket Facing Guide 1699/4BSA
• Italian threaded (36 × 24): Italian Bottom Bracket Facing Guide
• Cutter blade (replacement / spare): Bottom Bracket Facing Cutter 1699.1

The tool ships with the BSA guide included, which covers the most common threaded shell in the current Unior USA catalog. Italian-threaded shells need the Italian guide; T47 requires the matching T47 tap set first, then the facing tool with a T47 guide.

Specs

• Operation: dual-face facing, hand-driven via modular handle
• Cutter: hardened tool steel, replaceable
• Modular series: shares the 1695.1/4BI handle with the 1694, 1697, 1698, and T47 taps
• Made in Slovenia by Unior

Includes: Facing tool body, BSA facing guide, cutter blade. Italian guide and T47 guide sold separately.

Made in Slovenia, since 1919

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The 1699's cutter is hardened tool steel because the cut surface itself is the spec the bearings live with; a soft cutter that chatters across the face leaves a stepped surface, and a stepped surface is worse than no facing at all. The 1699 is built to leave a clean ring around both faces, first cut and last.

Pro tip from our mechanics

Apply cutting fluid generously. Light, steady torque on the handle. Let the tool cut. Forcing the facer produces chatter marks; rushing it leaves a stepped surface where half the face is cut and the other half is still painted or anodized. Watch the chip pattern: continuous curls means the cut is happening; powdered chips means the tool is dragging without cutting and you need more pressure on the handle.

The full BSA-shell prep walk-through (chasing threads first, then facing, with the right reference forces and the chip-pattern diagnostic) is in our Tech Tips: Frame prep: threaded bottom bracket shells →