I don't own that but I took a look at some pics. It looks like there's a little cap in the center of the wheel? You may be able to pop that off to get directly at the wheel bearing. That will probably work better than spraying something and hoping it leaks past the cap and into the bearing. My first impulse would be to use boat trailer grease for metal to metal, and Sil-Glide for anything involving plastic or rubber. But e-mailing Rimowa and seeing if they have a suggested lubricant or instructions on how to do it available would probably be a safer bet.