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Old 04-27-16, 07:06 PM
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steelbikeguy
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to those who are interested in the legend of the AVA "death stem", there is info floating around on the interwebs.

Personally, I received one with a frame I bought a number of year ago, and recently sold the stem. I never used the stem, but solely because it was incredibly flexible and really concerned me.

There were two main concerns about the AVA stem. The first was that the expander slots at the bottom of the quill had square corners, which promoted the formation of cracks. If cracks occurred, the quill could break, which is clearly not going to improve your bike ride.
Here's a shot of the expansion slot on my stem....



The other issue with the stem was the hollow extension. On the plus side, it does save weight. On the down side, it reduces the strength of the extension in two ways. The first way is simply that less material is used. As the mechanical engineers in the crowd will know, the material in the middle of a beam or tube contribute the least to the ability to resist deflection or torsion. The bigger problem is that stem was that the hollow center was produced by casting the stem. As you may know, casting produces a weaker structure than forging. Every modern aluminum stem that I can think of is forged.. at least the C&V ones are/were.

Here are a couple of pics that show the hollow extension..





As the second photo shows, there is a lot of material that is removed from the center of the extension, which is certainly one factor in why it felt so incredibly (torsionally) flexible to me.

and to close, a shot of the AVA logo on the extension..




Steve in Peoria
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