Park Tool LRT-1.2 E-Bike Chainring Lockring Tool - Bosch Gen 2 / DJI Avinox, 8-Notch, 50mm, 3/8-Inch Drive

The Park Tool LRT-1.2 removes and installs 50mm outside-diameter, 8-notch chainring lockrings on compatible Bosch Gen 2 and DJI Avinox e-bike motors. It accepts a 3/8-inch square drive for use with a suitable ratchet or torque wrench. This is the lockring tool, not a chainring or lockring.

Which motors does it fit?

Park lists Bosch Gen 2 Active Line with chainrings smaller than 20 teeth, Performance Line and Performance Line CX, plus DJI Avinox. The Bosch generation and the lockring dimensions both matter. Do not assume every motor with a Bosch logo uses the same tool, or confuse this with a cassette or disc-rotor lockring tool.

The LRT-1.2 replaces Bosch tool 0275009003. If you are unsure which motor is on your bike, identify the motor and compare the lockring before buying. Eight notches alone are not enough if the diameter is wrong.

What else do you need?

Remove the crank arm before accessing the chainring lockring. You will need the appropriate crank-removal tools and a suitable 3/8-inch drive handle; for installation, use a torque wrench that covers the motor manufacturer's specified torque. Check the service instructions for thread direction and any other required steps. This tool is for hand use, not an impact driver or other power tool.

The heat-treated, plated 4140 steel construction is built for repeated shop use. The useful part is a positive fit on the right lockring, which is considerably nicer than finding out what rounded notches look like.

Workshop help from WC

Our torque-wrench guide explains choosing and using a torque wrench. Use the motor maker's torque specification for this particular job, and browse component-specific tools for the rest of the work.

• Fits 8-notch chainring lockrings with a 50mm outside diameter
• 3/8-inch square drive for a compatible ratchet or torque wrench
• Heat-treated and plated 4140 steel; hand-tool use only