Shimano Direct Mount Lockring Tool

Shimano's direct-mount chainring system on the M9000-series MTB cranks (XTR M9100, XT M8100, SLX M7100, Deore M6100) eliminated the separate chainring-bolt assembly by threading the chainring directly into a lockring that mounts on the crank's spider. The chainring locks against the lockring at a published install torque; removing the chainring means turning that lockring with the right tool. A generic socket won't fit; the lockring's outer engagement is a specific notch profile machined for the Shimano TL-FC41 service tool.

The 1723.SDL is the workshop replacement for the TL-FC41. CNC-machined aluminum, sized to the Shimano direct-mount lockring's specific notch profile, red-anodized so it doesn't disappear into the shop's drawer of black tools. A 1/2" square drive on the tool body accepts a torque wrench for the chainring lockring's published install torque; Shimano specifies a value, and the 1/2" drive exists to honor it.

Pairing with the 1725/CF Crowfoot

The 1723.SDL is designed to pair with the Crowfoot Open-End Wrench 1725/2CF and a 1/2" drive torque wrench for the published install torque. The crowfoot allows the torque wrench to engage from off-axis, which matters on direct-mount cranks where the chainring's drive-side clearance to the chainstay is tight enough that a straight socket can't always swing freely.

Compatibility

• Shimano XTR M9100 cranks (direct-mount lockring chainring)
• Shimano XT M8100 cranks
• Shimano SLX M7100 cranks
• Shimano Deore M6100 cranks
• Shimano-pattern direct-mount lockrings on aftermarket chainrings that follow the same engagement
• Replacement for Shimano TL-FC41

Specs

• Material: CNC-machined aluminum, red-anodized
• Drive: 1/2" square drive (use with a torque wrench, ratchet, or fixed handle such as the Pro Socket Handle)
• Lockring fit: Shimano direct-mount lockring outer profile
• Includes: the tool itself

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 1723.SDL is the workshop's answer to a Shimano service tool that historically only lived in dealer service kits; a CNC-machined aluminum replacement with the right engagement profile, sized to take a torque wrench at the published install spec.

Pro tip from our mechanics

Direct-mount chainring lockrings sometimes seize against the crank spider after a season of riding, especially on bikes that see wet conditions. Before applying loosening torque, spray penetrating lubricant at the lockring-to-spider interface from the back side of the chainring and let it work for five minutes. The lockring backs off cleanly with the lubricant in place; without it, the lockring's outer notches can round under loosening torque before the lockring breaks free, which converts the chainring swap into a more involved removal.

For the crank removal procedure with chainring-access calls: How to remove a crankset →.