Here’s the installation sequence for the best fit: 1. Install the HBB mounts (those parts that bolt onto the handlebar); they need to be perfectly aligned both vertically and horizontally, and well tightened on the handlebar. 2. Loosen the clip plates (those parts that are bolted to the bag itself) so that they move freely. 3. Slide the clip plates onto the HBB mounts. 4. With the clip plates loose, you wiggle the bag so that the clip plates find their best position relative to the HBB mounts. 5. Tighten the clip plates bolts making sure that the clip plates stay in their exact position while you tighten them. Once this is done, just put a small drop of grease at the contact point/slot between the clip plates and mounts.