Park Tool BBT-7 Bottom Bracket Cartridge Tool (XTR)

The BBT-7 Lockring Wrench is used for installing and removing the lockring used on Dura Ace® 7700 and XTR® 950 Bottom Brackets. It is laser cut and engages five of the lockring's six notches for a precise, secure fit. The handle is vinyl dipped for comfort. While made specifically to fit Dura Ace® and XTR® Lockrings, it fits several other lockrings as well.

The major diameter of the tool is nominally 46.5mm. A ring can be no bigger than this size and fit the tool. The minor diameter (at the notches), is nominally 41mm.