Yeah, the ring is definitely a major pain in the butt. Bad, bad, bad design. I'm contemplating returning these. This is going to be a nightmare in Winter. And yeah, one is tighter than the other. Although, they're freaking bright!
A thought: since I'm using only one mode basically, perhaps I'll insert an inline switch and just leave the lights in the same mode all the time? I'd just need a waterproof switch.
Here is how I mounted it. I first bolted a short aluminum tube to the rack, then attached the two blinkies to to it:
