Bottom Bracket Facing Guide BSA

The 1699 BB facing tool needs a reference for its cutting axis. The shell's own threads are that reference, but only when the facing tool has something to grip the threads with. This listing is that grip, in two thread standards. Each variant is a paired set of inserts that screw into a chased shell and present a flat, coaxial mounting surface for the 1699's frame. Pick BSA (article 1699.4BSA) or Italian (article 1699.4ITA) to match the shell.

What this piece does

The BSA variant (1699.4BSA, code 626470, 240 g) is a matched pair of 1 3/8″ × 24 TPI inserts, stamped BSA-L and BSA-R. BSA-L is left-hand thread (drive side); BSA-R is right-hand thread (non-drive side). The R and L marks name thread direction, not frame side. The Italian variant (1699.4ITA, code 626469, 252 g) is a matched pair stamped ITAL M36×24 TPI; both sides are right-hand thread. Once either pair is seated, the 1699 facing frame passes through them and the cutter rides coaxial to the bore.

The guide is the piece that translates the shell's internal thread geometry into an external mounting reference for the cutter. Without it, the cutter has no clean coaxial line to follow; with it, the cutter's path is determined by the shell threads themselves, which is the geometric reference the bearings will eventually live on.

Compatibility

• BSA-threaded shells (1 3/8″ × 24 TPI) or Italian-threaded shells (M36 × 24 TPI). There is no T47 facing guide
• Mates with the Frame for 1699 Bottom Bracket Facer 1699.2/4
• Part of a complete Bottom Bracket Facing Tool 1699 setup

Specs

• Thread: BSA 1 3/8″ × 24 TPI (LH + RH); Italian M36 × 24 TPI (RH both sides)
• Pair: BSA-L + BSA-R on the BSA variant; two ITAL-stamped inserts on the Italian variant
• Function: threaded reference inserts for the 1699 BB facing tool
• Tightening: use the 1699.5/4P facing-guide wrench
• Made in Slovenia by Unior

Includes: BSA variant: one BSA-L insert and one BSA-R insert. Italian variant: two ITAL M36×24 TPI inserts. The 1699.5/4P wrench is sold separately.

Made in Slovenia, since 1919

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The guide is the geometric pivot of the BB facing operation; it takes the shell's own thread spec and converts it into the cutter's setup reference. Building the guide to that geometric responsibility means tight thread tolerances and flat outer faces that mate without rocking. The 1699/4BSA's working surfaces are the kind of small precision detail that decides whether the facing operation produces a square face or a slightly cocked one.

Pro tip from our mechanics

Chase the threads before mounting the guide. The guide threads in by hand; if it doesn't seat by hand the threads aren't clean, and forcing the guide will damage either the guide or the shell. Run the matching taps through first (BSA or Italian), blow the shell out, and then thread the guide in by hand until it bottoms against the shell face. Tighten with the 1699.5/4P guide wrench; finger-tight isn't enough to hold the guide square through a cutting operation.

Both guides should bottom against the same plane on the shell faces. If one side leaves a visible gap and the other doesn't, check whether the shell faces are out-of-parallel by enough that the facing operation will produce uneven cuts on each side; sometimes the answer is to start the facing pass and let the cutter equalize them, and sometimes the answer is to investigate why one face is so much shorter than the other before cutting.

The BSA-shell prep walk-through covers the chase-then-mount-guide-then-face sequence in order: Frame prep: threaded bottom bracket shells →

FAQ

What is the difference between the BSA and Italian options on this page? BSA (article 1699.4BSA, SKU 626470) is 1 3/8" × 24 TPI with opposite-hand inserts: BSA-L is left-hand thread for the drive side, BSA-R is right-hand thread for the non-drive side. Italian (article 1699.4ITA, SKU 626469) is M36 × 24 TPI with right-hand thread on both sides; both inserts are stamped ITAL M36×24tpi. Pair weights are 240 g (BSA) and 252 g (Italian). Pick the variant that matches the shell you are facing.

Does this listing include the 1699 facing tool or the seating wrench? No. This page is the spare guide pair only. The complete 1699 set already includes the BSA guide and the 1699.5/4P wrench; the Italian guide is an official option, not in that set. Unior specifies seating the inserts with wrench 1699.5/4P, which is sold separately if you do not already have the set.

Is there a T47 or press-fit facing guide for the 1699? No. Official 1699 facing coverage is BSA and Italian only. There is no T47 facing guide. Unior's T47 offering is the 1695.5 tap pair, which chases M47×1 threads; it is not a facing guide. Press-fit shells are a different system and do not use these threaded inserts.

Which insert goes in which side of the shell? On BSA, L and R mark thread direction, not frame side: non-drive side takes the right-hand insert (BSA-R); drive side takes the left-hand insert (BSA-L). On Italian, both inserts are right-hand. Official procedure puts the guide on the side opposite the face you are cutting, then repeats the sequence on the other side so both faces reference the same threaded bore.