cudak888 

From the Death Stems of France comes this surprisingly sturdy-looking ATAX. The expander slot is crack-free, and the bar clamp area is a thick and solid design in comparison to other designs. In as-pulled condition; hardware needs to be cleaned. 60mm c-t-c w/traditional French 22.0 quill and 25.0 clamp.

I'd recommend drilling a hole in the end of the expander slot to relieve the stress risers so that it won't crack later on.

$15 + 8 shipping via Priority.

verktyg 

From the 1940's up through the present, millions of cast aluminum stems have been produced world wide. Many are still in use.

Sheldon Brown (RIP) forever tarred the image of French cast aluminum stems. He coined the term "Death Stem" in reference to AVA stems, especially the ones used on 1960's - early 1970's Peugeot PX-10s.





ATAX was a different company than AVA. They made products under both the ATAX and Philippe marques (they made a lot of Milremo badged stems too). Their reputation was much better than a lot of the other French companies that made cast aluminum stems.

The real culprits were the French PIVO brand stems (and bars) produced during the early 70's bike boom years.

Here's an example of a dangerous PIVO sand cast stem that should have been thrown back into the melting pot instead of being machined and installed on a bike.

Note the casting flaws in the quill. Instead of being 22.0mm diameter, it's as small as 19.0mm above where the wedge has expanded the quill. Also note the radial crack at the top of the expander slot:



The cracks grow until the stem breaks off leaving the rider holding the detached bars. Happened to me while test riding several customer's bikes back in the early 70's. Fortunately I was able to safely stop the bike.

The cure is to prevent the cracks from forming in the first place by eliminating the stress riser at the top of the expander splits. A small round hole will suffice. You can use a Dremel tool, a small round file or a drill. I do it on all of my stems with this style of expander.



Getting back to the AVA stems Death Stems, several things to consider:

Was the bike in a crash?

How long is the stem?

Peugeot used relatively long stems on their 1960's through early 70's performance models: PR-10, PX-10 etc. Hard riders honking out of the saddle are more likely to put a lot of side to side torsional twisting forces on the stem, especially a longer one.

Here's my 1967 all original PX-10 barn bike as found. Note the 100mm AVA stem on a 54cm bike.



I've not seen a broken cast aluminum AVA stem but I've heard that they fail at the neck or bar clamp area rather than at the expander split like the PIVO stems.

In reference to @cudak888 stem, clean up the quill, inspect it for cracks, drill a hole at the top of the expander slot and you should be good to go.

As per ANY 45-50 year old bike component common sense should prevail. Because of the 60mm reach, it's going to be relatively stronger than a longer reach stem but I wouldn't plan on using it for an everyday rider or for hard riding. Great for C&V rides.

One other thing, these stems are drilled for 25mm bars. I'd be very careful trying to expand the clamp to fit a 25.4mm - 1" bar.

I've had the clamps on a number of 25mm stems machined out to fit the larger 25.4mm bars. You could probably sand out the bore too.




Happy trails....

verktyg

cudak888 

Thanks for the detailed Death Stem trilogy, Chas.

FYI, I should point out that I have been bitten by a casting flaw in a later (and much more refined) Phillipe/ATAX stem. Pretty sure the consensus was that my particular case was a one-off failure.

--Kurt

rhm

For what it's worth, there is a 3TTT stem that is notorious for breaking at the clamp. I don't know if anyone's died as a result, but I think they're just as dangerous as the AVA / ATAX ones.