Before installing any threaded bottom bracket (BB) it is vital that the bottom bracket shell is faced and the threads are chased by a professional bicycle mechanic

Debris in the threads can damage both the frame and BB

A misaligned BB shell will lead to premature bearing wear

A BB shell that is too wide can cause damage to the crank and BB. Even a BB shell that is only 0.5mm too wide can cause problems

Most good bike shops will have these tools and understand that this is an important part of frame prep

Now that the BB shell is prepared, measure it to ensure that it is in spec and to determine the number of spacers needed under the BB

BB shells should measure exactly or slightly under 68mm, 73mm, 83mm or 100mm depending on your frame, check with your local shop if your measurements are off before proceeding

Determine the number of BB spacers needed using the chart

Lightly grease frame and BB threads

Install the center tube into one side of the BB before installing

Install prescribed spacers on BB cup and thread into the frame

The drive side cup will be reverse (left hand) thread

The non-drive cup will be a standard (right hand) thread

If you are installing a BB mounted chainguide or an E-type derailleur it will replace one of the 2.5mm drive side spacers. When greasing the BB shell, be sure that the BB face and the guide mounting hole are free of grease. This will keep the guide from twisting.

Install the non-drive side BB cup making sure the center tube is properly aligned

Using the e*thirteen BB tool in conjunction with a 10mm hex bit and torque wrench, tighten the BB cup to 34-41nm

Determine the number of spindle spacers to use by referencing your crank model and BB shell width using the chart

How to install current cranks using the APS adjuster

How to install legacy cranks using the wave washer and spindle spacer preload system