Romp Supply

How to Install/Remove Bearings from the ATOMs

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. 

When applying the retaining compound, be sure not to let any creep through the bearing shields and into the ball bearings. A little goes a long way here. We recommend applying a small amount around the inner barrel, approximately where the bearings will finally sit (see photo). When installing the bearing, move it in slowly and let the retaining compound spread. Gently moving the bearing in and out of the inner barrel will also help spread the compound. Be sure to wipe off any excess after the bearing is seated to ensure a clean install. 
If you are re-installing older bearings, be sure to clean out all contact surfaces on the pulley and bearing ensure they are free of debris and grease. A wipe with rubbing alcohol is helpful hear. Once clean, apply the primer and retaining compound as you would with a new install. 
When removing bearings, all you need to do is tap them out with a hammer and a blunt object that will act as bridge between the hammer and bearing. Tap gently around the perimeter of the bearing until it comes loose. Make sure not to aim for the shields of the bearings! 
Still got questions? Shoot us an email at or send us a message using the Contact Us page.  

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