So I've been using a CB600S for a few months now, longest timeframe being 7 days. No issues at all. I bought a new stainless steel cage, and with the same ring size my nutsack turns a blue hue within minutes. I tried even the next size up ring and they still turn blue. Anyone know why?
I have a Chinese one with a hinged ring that does that every time, rendering it useless for anything but short term bdsm play scenarios. I think it's because steel is simply non relenting and limits blood flow differently than plastic. That's my only guess, which isn't exactly genius level.
With the CB 1 3/4 is loose, and 1 5/8 is about right. I've tried both of those sizes with the metal cage and both have caused the blue nut sack. They don't feel overly tight. My normal coloration comes back almost immediately when I take it off. Maybe it has to do with the steel? Cheap metal that I'm having a sort of allergic reation to?
Possible, there are some cages that have rings in 1mm increments. That would give you 3 choices between what you have. Cherry Keeper is hard nylon material rings and also have angle control of gag which could be the issue versus ring diameter. Also ergonomic shape instead of round which might help.
Have you tried a cage with a body shaped ring, not a round one (or vice versa)? It could be the shape of the ring (and the rigid material) doesn't suit your body shape.