That's my biggest complain about the chain(not sure what the proper term for them is) bracelet. They are so tight and rigid when you first buy them, but the more you wear them, and the more charms on them, the looser they get.
I have switched to the bangle, and like it more. I also like the bangle with less charms on it.
I like someone mentioned, had to put more charms on my chain ones to make them fit better, but now they are so heavy, it bothers me to wear for very long.
I wear 4 bangles, each with only 3 or 4 charms on each one, and am liking them. I can wear them without feeling my arm is weighted down.