Thanks again Joel! The 38L is the perfect fit to house a helmet, yet still narrow enough across the bike to allow Holan panniers to hinge open. You can absolutely run a 45L Large+ or 62L Extra Large (a.k.a. "The Mini-Fridge"
), but you'll need to undo both latches and lift the pannier lid straight off - the top case will hang over the panniers and prevent them from hinging up.
The 29L Medium case is a smaller cube-shaped version of the 38L - great if you need to drop tires over it for longer trips, but usually too small to fit a full-face helmet. My wife's small sized full-face HJC street helmet will *barely* fit in the 29L, and my Large helmet will not.
The 25L Photo case is great for commuting or if you plan to strap a Wolfman drybag to the top of the case. It's the same width as the 38L Large, but shorter in height.
We have a pretty good selection of top cases in stock now in various finishes and sizes, and they've been installed successfully on a variety of top case mounts. Any questions, or if you'd like to confirm availability on a specific case, please email me at sales AT advmotorrad DOT com or give the shop a ring at (585) 310-ADVM.
Thanks!