Congrats on your new set of ATOMs! Perhaps, you don't have them yet...In any case, we think this information on how to maintain them will be useful, no matter what position you are in. Below is all the information you will need to install or reinstall your own bearings!
Before we get into the nitty-gritty, let's take a moment and discuss why the ATOMs were designed they way they are. When it comes to the clearance fit between the pulley bearings and the inner barrel of the ATOMs, we choose to go with a "slip fit" for easier removal and installation. A "slip fit" basically means there is minimal friction between parts and requires no force to install (i.e. the bearing "slips" in). Beyond this type of fit is a "press fit," which requires a bit force to install the bearings. Although press fits result in a more secure hold in the absence of compounds, the amount of work needed to install/remove the pulley bearings, along with the risk of damage, is much greater.
In short, we wanted to make it super easy for our customers to remove and install bearings, whether it be for maintenance or replacement reasons. So we went with a slip fit!
With a slip fit, installation and removal of bearings is much easier, but the use of a retaining compound is necessary. It is possible to run the ATOMs without the retaining compound, but we have found that doing so causes unwanted noise and wear on the inner barrel as the bearing vibrates in as the pulley moves.
For your retaining compound, we recommend using Loctite 680. This is a high viscosity compound ideally suited for slip fits. In addition, since the ATOMs' anodized aluminum is inert, you will need Loctite SF7649, which is a primer and activator, making the Loctite 680 many times more effective.