The problem with "AVA Death Stems" is that nobody seems willing to post a picture of an actual, failed stem. AVA made several stems that were very light, and eventually a few of those stems failed.
1. It was explained to me on the last San Diego vintage ride that the AVA stem that fails has a hollowed-out extension tube. The hollowing-out goes all the way to the stem head. As a result, the handlebar clamp area stresses the aluminum and cracks form near the the clamp nut-area, eventually causing failure.
2. It was explained to me previously in a CR thread, that the AVA stem that fails is hollowed-out at the back. The stem is not supported in the back and so the expander bolt exerts a great deal of force on an O-shaped piece of aluminum that eventually fails.
3. It was explained to me in another forum that the AVA stem that fails has a slot cut in the middle of the head of the stem, that supports the handlebars. This slot weakens the stem head or whatever, and it eventually fails.
I am still in search of pictures of the "elusive, failed AVA death stem".
- Don Gillies
San Diego, CA