Aluminum Bottom Bracket Socket E13

e*thirteen's cranksets ("e13" on most shop benches) ship with bottom bracket cups cut to e13's own outer-notch geometry. The dedicated 1671 Aluminum BB Socket for e13 sizes specifically to that engagement profile, so the splines mesh fully across the cup notches under install torque, and the aluminum body matches the cup's hardness so there's no metallic scarring on the anodized outer face.

Where this socket fits in the workshop

A shop that services modern MTB builds with e*thirteen cranks; often paired with SRAM Eagle drivetrains, often on enduro and downhill bikes; benefits from an e13-specific socket on the bench rather than a generic 16-notch wrench. The dedicated cut keeps both the socket and the cup engagement clean across multiple service cycles.

Compatibility

• e*thirteen crankset BB cups (e13 outer notch profile)
• Cups marked "e13" or following e13's outer engagement geometry; verify the cup's marking before applying torque
• Not for generic Shimano-pattern 16-notch cups; use the BBR60, BB9000, or 16-notch generic socket instead

Specs

• Drive: 1/2" square drive (use with a torque wrench, ratchet, or fixed handle such as the Pro Socket Handle)
• Material: CNC-machined aluminum, red-anodized
• Notch fit: e13 outer profile
• Includes: the socket itself; pair with the Bottom Bracket Socket Retaining Tool when the cup runs low-profile

Built in Zreče

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The e13 socket completes the 1671 family's coverage of the BB cups that show up in modern MTB workshops; the aluminum body keeps the cup face mark-free across the install and removal cycles a high-use bike sees over a season.

Pro tip from our mechanics

Verify the cup's outer engagement profile visually before reaching for either the e13 socket or a generic 16-notch one. If the e13 socket rocks or fits with play, the cup is likely cut to a different profile; conversely, if a generic 16-notch socket binds or sits proud, the cup is specific to e13's geometry. Five seconds of test-fit before applying torque is what keeps the cup serviceable for the next install.

For verifying e13's outer profile against the 16-notch envelope before applying torque: Replace or clean your bottom bracket →.