At the risk of somewhat disagreeing with the esteemed Mr. Brown, I do not follow his advice to automatically replace AVA stems. These stems have been known to fail, but then Campy NR cranks were known to crack at the junction of right arm and spider, and I know of no one automatically replacing all NR cranks just because of that. As discussed here many times, all aluminum components are subject to fatigue stress cracking and therefore will theoretically all eventually crack if used long enough, although long enough in some cases may be several human lifetimes.. I've personally not had an AVA stem fail, but I have found cracks in AVA bars and prompty removed them from service.
Also, I believe the AVA stems Sheldon warns about are the "faux lugged" type. This type of stem was used by virtually every significant French manufacturer in the late 60's and early 70's. What appear to be identical stems can be found not only marked as AVA, but also as several other French brands or with no brand at all. Therefore, I'm not at all sure AVA actually manufactured the stems in question. Until someone reports actually witnessing these being manufactured at an AVA factory, I'm inclined to believe that one French company, possibly one we never heard of, manufactured these and marked them with the brands of the companies distributing them, including AVA and all the others.
So to me it makes no sense to avoid AVA stems unless one is also prepared to avoid all alloy stems of the same design. Now if you want to be cautious, maybe avoiding them all would be a good idea. Personally, I think this is overly cautious, since the only sure way to avoid fatigue stress component failures is to never use any alloy component. I do think one should inspect alloy components regularly for cracks, particularly those with reputations for cracking, like "faux lugged" stems, AVA bars and Campy NR/SR cranks. In addition to the AVA bars, regular inspections have allowed me to detect cracks in a couple of Campy cranks and remove them from service before a potentially dangerous failure occured.
Regards,
Jerry Moos Big Spring, TX
hersefan@comcast.net wrote: AVA I believe was making alloy stems before the WWII. Does anyone know if the very early ones were more or less reliable? It seems that many French parts were made to lower and lower quality standards by the 60's and 70's - did the AVA stems suffer this fate as well, or were they always a source of concern.
Mike Kone in Boulder CO
> Paul Cooley a écrit:
\r?\n>
\r?\n> >I was reading Sheldon Brown's website on French bikes, and he states that t
\r?\n> he
\r?\n> >AVA stems are not safe and should be replaced. Does anyone know why they
\r?\n> >aren't safe?
\r?\n>
\r?\n> 'Cause they're liable to break, and then the handlebars fall off.
\r?\n>
\r?\n> When the handlebars fall off, it is hard to keep the bike from crashing.
\r?\n>
\r?\n> Crashing hurts! ;-)
\r?\n>
\r?\n> Sheldon "Details, Details" Brown
\r?\n> +-----------------------------------------+
\r?\n> | Well, the truth is usually just |
\r?\n> | an excuse for a lack of imagination... |
\r?\n> | --Garak, DS-9 |
\r?\n> +-----------------------------------------+
\r?\n> --
\r?\n> Harris Cyclery, West Newton, Massachusetts
\r?\n> Phone 617-244-9772 FAX 617-244-1041
\r?\n> http://harriscyclery.com
\r?\n> Hard-to-find parts shipped Worldwide
\r?\n> http://captainbike.com
\r?\n> Useful articles about bicycles and cycling
\r?\n> http://sheldonbrown.com