SRAM Rival/Force 22 crankset question

bruto0 Posts: 8
edited January 2015 in Workshop
Hi, everyone

seeking collective wisdom regarding the design of these cranksets and their chainrings.
Took my Rival 22 crankset apart, found that while it copies Red 22 in appearance, the design is different.
Namely, there's a threaded insert in the hole of the big ring that lines up with the hidden spider arm and a special bolt that goes into it (since it's pretty hard to use a regular bolt&nut in that hole, even if I saw a hex wrench's short end off to make it even shorter).
Question: how does anyone use other chainrings with this crankset? Tighten the hidden bolt by hand, with one hex wrench? Remove the crankarm to gain access to the hidden spider arm (requires removing the crankset from the frame)?
And does this mean that Rival/Force 22 big ring is not 100% compatible with Red 22 crankset (since the threaded insert prevents Red's own long hidden bolt from going all the way to the crankarm)?
I was able to use Rival's bolt with Red's spacer to bolt the two chainrings together, but they're not attached to the crankarm at that hole, which is less than ideal. I thought I'd be able to use the Red 22 crankset and switch between smaller CX chainrings and larger Rival ones depending on need.

Here's a picture of a Force 22 crankset sans crankarm from ebay, for those who need one. The hidden bolt hole is on the right, note the lack of regular nut.