Could someone explain Bead lock wheels to me? I understand they allow you to air down and prevent the tire from slipping off the wheel,
Yes, this is correct.
but I was watching an installation video where the guy inserted a couple beads inside the tire and said they balance the wheel by finding the light spots. This confused me.
What you probably saw was someone using "Dynabeads". These are small beads inserted through the valve stem, which actually roll around inside the tire. This helps to balance a tire at normal street and highway speeds from having otherwise unruly manners. This is typically done when normal road force balancing with lead weights does not help oversized tires. "Dynabeads" have nothing to do with keeping the tire from losing its seated bead against the rim/wheel lip.
Also the locker ring is what I thought kept the wheel from slipping off because it went up the sidewall a little bit to create more resistance. However the one he put on didn't seem to go any higher than the wheel did. Maybe I just saw it wrong. Could anyone explain to me how it works?
Yes, the bead lock ring clamps the tires steel bead to a flange surface on the wheel. The beadlock ring only needs to be the height of the tires steel bead. Try watching this video of "how to mount a tire on to a beadlock wheel", it's one of the clearer example, although there are many different techniques to mount the tire to the rim, this basic principle about covers it.....and it's not usually as easy as the tire this guy mounts.
http://www.youtube.com/watch?v=KIYrGJmHM78&feature=youtube_gdata_player
Edit: I just realized this is probably the same video you watched
hopefully I at least cleared up the Dynabeads thing for you.
