Here's a couple of photos from my set-up. Like El Flaco suggested, I have 2 foot sliding tracks mounted on my walk rails. I slide the Bimini all the way forward to shade passengers, then slide it all the way back to clear my gear pile when folded down. You can kind of see the track in the close up photo. I also have it mounted backwards (with the longest bow which attaches to the frame angled toward the front) to create a larger space for the oars. You can fold it down either to the front or back.
The stings you see behind me in the close up photo are cross bracing for windy days. Makes a big difference for stability in stronger winds.
Let's get on the river together this summer,