The BTS-1 is a precision tool system for ensuring threaded bottom bracket shells are properly aligned and faced. The precision-manufactured two-piece tap handle engages through the bottom bracket shell, ensuring both sides are aligned with the shell and each other. The included English-threaded taps precisely verify and repair the alignment of threads in the shell. After tapping, the taps act as guides to keep the included facing cutter perfectly square with the axis of the bottom bracket for cleanup of the faces of the bottom bracket shell.

Includes:

• 1.370" x 24 TPI right hand tap — English non-drive side (part #691)
• 1.370" x 24 TPI left hand tap — English drive side (part #692)
• 45 mm facing cutter (part #690)

Also available:

• 36 mm x 24 TPI right hand tap — Italian (2 required) (part #693)
• M47 x 1.0 right hand tap — T47 (part #647R)
• M47 x 1.0 left hand tap — T47 (part #647L)
• 57 mm facing cutter (part #690-XL)

NOTE: Always use cutting fluid such as Park Tool CF-2 when machining.