Hello,

Have any Peugeot owners dealt with replacing the AVA stem on their bikes? I hear they're prone to failure, and it seems like something that could get really unpleasant really quickly if it failed at any sort of speed. From what i understand, the measurements of the stem are odd and difficult to find. Any ideas? Can any other stem be made to fit?

And, can any Peugeot owner with a six digit serial number on the dropout give me an idea of the age of our bikes? I read somewhere that such a placement means late sixties - early seventies. Is this accurate?

Thanks in advance.

-Adam

unpleasant very quickly. The second most dangerous part on the bike (less the fork). Other stems will fit (ATAX comes immediately to mind, Phillippe as well). Lose the AVA if you want to ride the bike.

The difference between the "standard" stems(22.2mm) and the French(22.0) is only 0.2mm. 10 minutes with some relatively course sand paper will allow a "standard" stem of your choice to slide into the French fork.

Ok... I'll work something out. It's nice to know i could sand down a standard stem if needs be.

What's the deal with the fork? Is that sketchy too?

Anyone know a good source of older stems? I don't really want to put anything on the bike that looks new...

Thanks for the advice.

You might want to read what Sheldon Brown has to say about French bikes. He has a lot of good info. Go here;

https://www.sheldonbrown.com/velos.html

In case you miss the link on Sheldon's page, go here also;

https://www.sheldonbrown.com/kunich.html

A Pivo stem would be another choice as an age-appropriate replacement.

If you go this route, just be advised the clamp diameter of the French handlebar is 25.0 mm, as opposed to 25.4 for others or 26.0 for the "Italian" standard, so another can of worms opens. Either have to shim your French bars or get new ones.

"It's always somethin'", as Rosanne Rosannadanna used to say.

And shimming those French bars can be enough to make you tear your hair out. I've got a set of French bars I wanted to use on a Raleigh; no way would the clamp close down enough, and finally it was taking so much shim stock I gave the whole thing up as a bad idea.

just how many beer cans did you chop up before you gave it up?

Cans!? You're supposed to use cans? No wonder I cut my fingers all up...

It's worth noting that some el-cheapo Huffys used 22.0 stems - though I don't know about clamp diameter; I've got a couple of SR stems from pulled old Huffys that went to the scrapyard that fit a French headset. Decent quality - same as most SR stems - but obviously nothing special.

Dostoy -

Thanks for posting! I just picked up an older Italian bike and just today managed to wrench the stem free so I could adjust the bars. It was marked "AVA Made in France." So these are prone to failure??? Yikes!
Glad to find out here rather than in the street...

Oh well, I could use a longer stem anyway. Now I just have more reason to get one.
Thanks again!

I just want to let everyone know I just got back from riding my AVA stem-equipped bike, and I'm still alive!

Frankly, I think this 'death stem' business has become an urban legend; everybody seems to 'know somebody who knows somebody' who broke an AVA stem, but I've never heard a reasoned explanation of how and why they break, and never seen broken one myself -- or even a picture of one.

But a friend of mine knows a guy who found a finger in his AVA stem once.

ask and ye shall rx. stem was like this when I bought the peugeot u-o8 from the thrift store, there is a matching lower piece but I couldn't find it in the garbage. don't know why, overtightened? accident? bup, but it is indeed broken ava.

Yes... I too have questioned the validity of the "death stem" label. While hunting for a replacement for mine, I've come across bike shop websites selling AVA stems that they specifically state are "NOT THE DEATH STEM!" I have no idea how they know this or if they even know at all or are just trying to unload crappy stems on people. But, I don't imagine every stem that AVA ever made is faulty. Maybe a contaminated batch of metal that produced a few thousand stems or something? If they're so bad, why are they so common on all these old bikes? Shouldn't decades of riding have snapped them all off by now?

On the other hand, I really, really don't want my stem to break while I'm riding - for my sake and the sake of whoever is riding/walking/driving near me when it happens. That picture is unsettling...

unsettling. I always thought that the moulding on the stem was a stress riser, and that the horizontal part of the stem broke ahead of the step. AVA's were very badly looked at by the time I started racing, and I never had any experience with one. The later '80s Modolo, however, broke with alarming regularity across the handlebar fixing bolt, leading to several disasters that I, personally, watched in the peleton. I applied my "learning by observation" training and dismantled my own modolo stem and went back to Cinelli and Cinelli. All of you with this type of stem: you can run your thumbnail around the edge of the handlebar fixing bolt hole. If it snags, you've got a crack started and a Modolo death stem about to be made. Kinda off thread, but strangely appropriate, don't you think?

Threadbump:

Lots has been said on the AVA Death Stem. I don't intend to take my chances with it, but I have recently picked up two sets of AVA bars cheap - one road, one track. Sheldon indicates that these too fail, but in my googling, noone else has tales of bar failure (maybe because the stem always fails first?)

Are these safe to ride?

A couple of years back when I became afflicted with the French bike disease I did a lot of googling on the AVA death stem, as a couple of my early finds were so equipped. From what I could find back then (links long since forgotten) the "Death Stems" are those where the handlebar clamp bolt is horizontal (parrallel to the ground). This may also be applicable to some brands other than AVA. I have a couple of bikes with AVA stems where the clamp bolt is vertical, which I have ridden quite a bit with no catostrophic failure, or signs of cracks.

I rode a UO-8 with that AVA stem on for over a year, and someone rode it before me for several years.

The rumors of their demise have been greatly exaggerated.

Anyone care to see one cracked at the top of the wedge expander slot?

-Kurt

ah. but of course. We love evidence that supports our BS...

I think people see AVA and assume the worst, by all means there were only certain stems that were deemed the "death stem"

Also to the O.P.
Belleri made some nice french stems too. You might find a few on eBay (hint hint)

AVA had made a great many different models and for many many years. I have never been clearly shown which of the specific stems are the dangerous ones or where exactly they tended to break. I ride with several different AVA models which show no signs of failure... but, of course, that's like saying my Ford Pinto has never exploded. On the other hand, I have indeed seen someone's photos of unmarked French stems which looked like very oxydized and neglected generic stems which had indeed failed. Perhaps there was a cheaper grade of aluminum used on some stems. The better quality brands were often made with "duraluminum" which was/is a very old and long proven strong alloy composition.

The AVA stems in particular were indeed known to be very light weight, and some had quite thin walls in certain areas, so I don't doubt the legend at all. I was told the failure points were not at the clamp areas (which is where I would have expected) but rather at the rear of the stem - just fore of the expander bolt and quill column. That makes sense too, since a lot of body weight placed on low drop handlebars of racing bikes may have been directed back to that pivotal unsupported section between the expander and the bar.

I tend to ride very UN-aerodynamically with nearly level stems and saddles, with minimal weight resting on my handlebars, and I never heave my bikes laterally during Power Sprints, so I was always little concerned about MY personal stems snapping...

However, if you ever see badly "brinnelled" (pitted) headsets you are viewing the long term effects of the repeated hammering of the ball bearingss against the same points on the steel cups, so even slight road vibration (translated as "bouncing") transmitted through the fork and the entire steering unit DOES have a significant eventual effect on even the strongest of materials - and aluminum alloy stems were always considerably weaker than steel cups and bearings.




That stem looks a lot stronger than some of my stems...

I also run with scissors... and I seldom wear a helmet. ... Your mileage may vary

I've had good success shimming bars by using sections of aluminum seatpost shim material--they come in all kinds of thicknesses, just do the math between the stem and the bars, find a shim that has the same difference between seatpost and seat tube, hacksaw off a piece that matches the width of the stem clamp and you're all set. Since the outside diameters won't match even though the thickness is correct, you may have to fuss with it a little to get everything together. It worked very well for me when I shimmed a set of 23.8 mm Raleigh North Road bars out to fit a modern 26.0 Nitto stem. I temporarily tightened the shim around the bars with a hose clamp, worked the end of the shim into the stem clamp, then slid the hose clamp off. Neat, clean, cheap, worked like a charm.
JV

I've yet to see an AVA cracked at that juncture, and I will not believe it until I see one.

The only thing remotely likely to crack on that example is the expander area, just above the slot. AVA slotted the stem twice, as opposed to once, allowing someone to conceivably flare the bottom of the stem out enough to start a crack. The square cut at the end (as opposed to a round hole) doesn't particularly help. This is an early-mid '70s stem:

She's already cracked:


Double slotting (also seen on Sheldon's stem). Get a load of the angle that the cracked portion is sticking forward:



...which can result in this:



I've always thought that the clamp mechanism on these were prone to failure as well though - the thin design of the example I show above pinches and deforms the bar clamp more then it assists. Sheldon's stem (a much older stem, probably from the early '60s) doesn't even come close as a candidate for it. I also have a later '80s AVA stem that appears to rectify the beefiness of the clamp:



...and the slot, which is now a single opening at the rear with a triangular taper at the top - supposedly for strength, but those sharp edges are still stress risers:



-Kurt