How to Install a Deore LX Bottom Bracket

A quiet bicycle is often the difference between having your friends talk to you during the ride or talk about you after the ride. Since it rotates and stresses with every pedal stroke, one of the worst culprits for noise can be a creaking or worn-out bottom bracket. You have removed the old one and the shiny new Shimano Deore LX bottom bracket is ready to go in. Fortunately, this installation is a relatively straightforward process.

Things You'll Need

  • Rag
  • Metric tape measure
  • 2.5-mm spacers
  • Grease
  • Anti-seize compound
  • Bottom bracket tool
  • Torque wrench
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Instructions

    • 1

      Wipe out the threads inside the bottom bracket shell with a rag. This will remove old grease or other lubricant and any metal shards that may remain from when the old bottom bracket was removed. This also ensures the new bottom bracket will thread in more easily.

    • 2

      Measure the bottom bracket shell with the tape measure. Many current bottom brackets fit both 68 mm and 73-mm bottom bracket shells. So, even though a 73-mm Deore LX will fit both, the measurement determines whether or not spacers are needed. If the shell is 68 mm, two 2.5-mm spacers will be needed for installation.

    • 3

      Apply grease to the threads on both sides inside the bottom bracket shell. This helps to thread the new bottom bracket in more easily. It also reduces the chance of the bottom bracket creaking and aids in removal if the bottom bracket has to be changed again in the future. On titanium frames, however, use anti-seize compound instead of grease. This prevents galling -- a type of corrosion that can occur when titanium is in contact with a different metal.

    • 4

      Thread the left-side cup into the bottom bracket shell a few turns by hand. This is the cup that is separate from the axle. The left-side cup tightens in a clockwise direction.

    • 5

      Insert the axle from the right and begin threading the right-side cup into the shell. Almost all bottom brackets in the U.S. are English standard threaded, so the drive-side cup threads counterclockwise. If spacers are needed, install them between the bottom bracket cup and the shell on the drive-side.

    • 6

      Tighten the right-side cup with the bottom bracket tool and the torque wrench. The lip on the cup should tighten up against the shell. Torque is very high -- generally between 435 and 605 inch-pounds. Remember, this side will tighten in a counterclockwise direction.

    • 7

      Tighten the left-side cup to the same torque specification. Remember this side tightens clockwise.