AZORCH

It's been a rainy couple of days so I decided be productive by organizing and cleaning up some of my parts stash. I love making a little shiny magic with Mother's, so out comes the dull and dingy. As I'm cleaning the grunge off of an AVA stem I'm a little stunned to see evidence of near failure:



Upon further inspection I discovered you could see a bulge on the obverse side of the stem. So, I'm calling this one a "near death stem."



At least the bars look shiny.



Rest assured, this one is going into the "Do Not Use" box.

steelbikeguy

well, if you have to find a crack or deformation in a stem, this is the way to do it!

Seems like an odd place for a failure to occur. Is there some sort of stress riser or discontinuity on the inside of the stem at that location that might explain the near-failure?

I'm assuming that this is a forged stem too... can't rule out the possibility that it is actually a cast stem, though.

Steve in Peoria
(sold my only AVA Death Stem a month or so ago, with full disclosure)

CannedPakes

Wow. Has anyone here actually had a stem fail on them mid-ride? What happened?

ThermionicScott 

That's interesting -- now I'm curious to see what would happen if it were installed in a junk fork and had the bolt cranked down until failure.

steelbikeguy

for reference and some background, let me attach an article from the February 1971 issue of Bicycling! magazine. It was written by Chuck Harris (creator of wonderful helmet mirrors and general innovator), and discusses headset bearing maintenance. By chance, it also contains a drawing of an AVA hollow cast stem and the admonition to drill out the end of the expansion slots to reduce the chance of cracks forming. No mention of what nasty things happen when cracks form.



disclaimer: I didn't scan this article, so let me thank whoever did (whomever?). Also, the material is presumably copyrighted, so the material will be removed if requested.

Steve in Peoria

Sir_Name 

They were never heard from again... Dun Dun Dun!

ThermionicScott 

As usual, Jobst Brandt had done there and lived to tell about it: https://groups.google.com/d/msg/rec....E/urr_qfS4EnQJ

AZORCH

Interesting, and pretty much time appropriate too. This stem came off of a Peugeot PR-10 purchased in the Netherlands in 1973.

3speedslow

Got a nice package deal on some Rando bars with brake levers, stem with Suntour shifters for 25. Quite pleased as this brings parts to several project. Even came with good cables and the old school metal cable housing to boot.

Cleaning up everything I get to the stem, an SR AX-120mm forged one. Bit grimy so gave it a polish. This is what I found On the front lip where the bolt hole is showers a crack all the way around. I usually inspect before putting things back into service and this is the reason. One death stem avoided.

fender1

I stopped using old stems, handle bars, cranks and seat posts for bikes that get ridden. Vintage aluminum is great to look at and polish but given so that so much riding on it (pun intended), I don't see a need to take that kind of chance for to save a couple of bucks.

3speedslow

All my bikes get ridden. What's the sense in having one if you aren't going to ride it.

There's no "need"to, but a desire to equip my vintage bikes with vintage parts. That is why the inspection is a must. I have put aside many stems and handle bars because of inspections.

i certainly don't use vintage parts to " save a few bucks "

noobinsf 

I wish it were to save a few bucks. Unfortunately, to keep things relatively period-correct (which doesn't always matter, of course), the difference between used and NOS can often be tens or hundreds.

Nice catches, AZORCH and 3speedslow, and glad you were able to find those failures the easy way...

Salamandrine 

Yeah, I think that vintage bikes are sort of artworks that are rideable, and the reasons for running vintage parts are rarely "to save a couple of bucks". Most people wouldn't buy some 1935 car, and then stick a toyota engine in it because it is practical.

Even so, sometimes that hot rodding type approach makes sense. It's fine with me as long as the decision is made deliberately. These days I'm agreeing more with fender1. There's no way I'm going to run some old cast stem made out of melted down scrounged surplus WWII aluminum. I chose to go modern, but there were vintage stems that were fine, 3TT and Cinelli for example. 3TTT stems were often used to replace AVA stems on PX10s etc BITD. They were a little undersized and even the 22.2 would usually fit right in. So if you do want to do a vintage period correct build, that is possible too.

fender1

All true. I am not that concerned on the period correct/vintage parts aspect of things.