this is a famous problem with Aluminum metal fatigue---all at once, just *snap*. doesn't mean there aren't good AL frames or parts; just that when (if) it goes bad, it's prone to sudden total failure. (and it doesn't mean that steel won't break; but you'll probably notice it before it reaches catastrophic failure.) i guess that "snap value" is also an issue for CF users, though it falls outside of my experience with metal fatigue.