KenNC

Picked up a 1974-ish Peugeot UO8, and it came with a Philippe stem, rather than what I thought would be the more common, and reportedly prone-to-failure, Pivo or Atax, stem. Curious if anyone knows if these were sometimes standard, and what is their reputation for reliability. Thanks!

JohnDThompson 

AVA stems are the ones with the reputation for faulure:

Many higher-quality French bicycles of the '70's came with AVA brand bars and stems. These have a reputation for failure, and should be replaced.

oneclick 

Each of the two types of quill fixing arrangements has a problem the other does not have, but the slit-quill's problem is worse. As is known, the top of the slit is a stress-raiser, and cracks start there and propagate around the circumference leading to separation and often sudden loss of control. Wedge-stems can distort the steerer - if not aligned when this happens then maintaining a corrected alignment can be troublesome, and headset adjustment should be done with the quill tight.

I use slit-quills after checking for cracks and if none then drilling and smoothing a hole at the top of the slit(s).

p.s. That's a nice looking stem.

verktyg 

St. Sheldon's obsession with AVA stems and the "Death Stem" connection is something I take issue with.

These were the AVA model stems that Sheldon railed the most about. They were used on PX-10s from the late 60's through the early 70's.




The 3 most common brands of French cast aluminum stems during the Bike Boom era were, AVA, PHILIPPE (ATAX) and PIVO. In my experience during that time, PHILIPPE were the better (can't say BEST about any of those stems) followed by AVA and the true Death Stems, PIVO.

Peugeot used AVA stems almost exclusively during those years. I never witnessed a problem but most of the reported failures with AVA stems that I heard about or looked up occurred in the clamps or right behind the clamps or possibly where the necks transitioned into the quills.

Saw almost no problems with PHILIPPE cast stems. Bertin used MILREMO badged PHILLIPE stems up until 1975-6.



PIVO stems especially from the height of the boom had 2 primary problems. A lot of the casting were such poor quality they should have been thrown back into the melting pot and never left the factory. Instead many ended up in Gitanes from ~1972-73. The second and more serious problem was at the top of the expander split or splits.

More so that any other brand, because of the poor quality castings, cracks propagated in that area and eventually the bottom of the quill broke off. It happened to me twice test riding customer's bikes. Fortunately I was able to safely stop.

This supposedly 22.0mm PIVO stem was a small as 20.0mm in area of the casting flaws. Note how it tapers out to 22.0mm at the bottom, also the crack at the top of the expander split.




Another thing that contributed to the problem was running with the stems to high. That was something inexperienced bike mechanics and owners frequently did.

Millions of cast aluminum stems were produced from the 1940's up to the present. Modern cast aluminum stems are produced by injection molding or pressure casting and go by the euphemism "melt forged".

By the end of the boom in 1974, the French stem makers changed their designs and improved their quality so there were far fewer problems.

If you have any of these cast aluminum stems, carefully inspect them especially at the tops of the expander splits. Take a drill, burr or small round file and round out the tops of the expander splits to reduce the possibility (probability) of a stress riser forming a crack. I do this with all of my quill stems that don't already have them.




Those old cast stems are probably OK for casual classic rides but not suitable for hard riding.

Cinelli, 3TTT and Nitto forged stems are far safer.

verktyg

noobinsf 

To Chas's point, your Philippe looks like it is on the verge of being too high -- please do check that out.

I happened to have one of those Ava death stems on a Puch I overhauled several years ago. Here is a link to the post where I zoomed in on the crack, which had propagated over the years. It was one of the Ava stems with the clamshell type clamp for the bars. https://www.bikeforums.net/19324040-post40.html

juvela

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the Philippe product always seemed stiffer/more rigid to me than the AVA & Pivo

one feature appreciated from this maker is that their 22.2 size comes with a 25.4 clamp, opening up a big wide world of bar options vs the frankish 25.0 size


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