Been there, done that. Not fun.
If you're a road rider, there really isn't much you can do in the way of
armor. The best protections you have are pretty much limited to gloves,
and making sure you're wearing close-toed shoes, preferably leather.
As an aside, I notice how many motorcyclists not only don't wear helmets
(we're not a state with mandatory helmet laws), but have no other
protections, including short sleeves or tank tops, shorts, and
inadequate shoes, including flip-flops.
Adequate clothing and shoes won't protect significantly against falls
that cause broken bones, but can help a lot with falls that rip up
For armor, there may be a little bit that mountain bikers use, but the
better place to look may be in the realm of skate boarders. For the
people who do armor there, beyond helmets, the most common stuff tends
to be padding for elbows and knees and writs. I think that for a
cyclist, knee pads and wrist guards are likely to be too constrictive,
and I'm not convinced that elbow pads will really do that much for you.
The most likely falls you have on a bicycle that would cause bone
breakage would be falling in a way that you try to catch yourself with
your hand (where your wrist is vulnerable), or where you hit your
shoulder and break a collarbone.
I'm not aware of any armor that would protect against those, or ribs.