Is it worth it paying for the extra cage ring? How big does the cage have to be considering inside diameter before the vertical bars really pose a security problem?
Why do you think you need an extra ring? As each cage is custom-built, it's very difficult to comment on how big it needs to be. Inside diameter depends on your own girth when flaccid, and making sure it's not so snug as to impede urination.
Yes, I was not certain of the gap. So it was far cheaper to get an additional ring with a different gap size than have to send the whole thing back to get resized. Postage costs alone make it a better idea.
I need the inside diameter to be slightly bigger than a CB since that's the main reason it didn't fit me. I just meant the larger the diameter the more space between the bars... It's probably not a big deal. I'm looking at 2.5 inches cage length so I just think the extra ring might be overkill.
Increasing the diameter would probably only be in fractions of an inch (or a few cm), so the spacing between the bars would be pretty much inconsequential. At best you might be able to squeeze a fingertip slightly more into one of the gaps at the head. You'd have to seriously size up a Jailbird cage to have an effect on the bar spacing.
First, you are talking about the option to have an additional ring on the cage right? That extra ring is primarily for looks, not security. My first JB has it because I kind of liked the extra ring appearance. But it does add some weight to the cage, so when I ordered a second, slightly smaller and shorter JB as one of my two primary cages, I did not add the extra ring. If you are asking about a second base ring then I apologize for mis reading.