The aerodynamics of an open top box at speed

[Gone in 60]

I had an interesting lesson in aerodynamics this morning. One of my projects during the holiday week was to tune up my Givi V47 top box. Givi sent me a warranty replacement for a cracked piece of trim on the latch years ago, but I never bothered to replace it until last week. Doing so made the latch as stiff as it was when the box was new, which I didn't pay enough attention to.

Since my wife made some treats for me to take to work to hand out for New Years, I used the V47 today. I packed it with my lunch, wallet and the plate of treats. On top, I had a stack of loose paperwork I needed to take to the office. During my morning routine as I suited up in the garage, I gave the lid a push, turned the key, and put it in my pocket. I didn't push hard enough...

Once I got to the freeway, being New Year's Eve, the morning commute was extremely light, and I was going about 80 mph. A few miles in, a car pulled along to the right of me and was motioning. I thought it was a "Cool Bike" thumbs-up, until I caught my shadow on the road. The silhouette showed the lid to my Givi standing straight up.

With the light traffic, I was able to pull to the shoulder easily, stop, and wince as I walked back to see what was missing. Thankfully, only the papers had blown out, and my wallet, lunch and treats were secure. I reprinted the spreadsheets when I got to work. But I've been mulling the aerodynamics of the thing to think of how the air movement would lift the lid of my top box and keep it vertical while riding at speed.