Just plain dangerous? (ebay content)

Are these kind of lightweight retro aluminium handlebars likely generally safe to use these days, or does it depend on the brand and the condition?

well...I had a pair of lightweight bars which I sold recently. They were bought in the early 90s, were ridden for around 50 miles, then went into a store cupboard in a cool dark place for over 30 years. They were subject to no stress, no heat and no chemicals other than cool air. On that basis they will have continued to possess all the metallurgical and physical properties they possessed when they were originally produced. I had no qualms selling them. However, the bars where I had a massive shunt and were subjected to huge destructive force, and twisted in the stem, causing a massive gouge - are are certainly fit only for recycling.

Old, thin walled, unused = absolutely fine
Old, thin walled, well used and never subjected to forces above design spec thresholds = almost certainly fine
Old, thin walled, hopelessly abused = discard

the original Pace sub130s were VERY thin walled. Below 130 grams and not ti - amazing. But then Renthal really know what they are doing. I rode them in VERY demanding conditions in their time. Trusted them, looked after them, and they looked after me.

Keith Bontrager wrote an excellent and sobering article on the subject of handlebars and product safety in an old issue of Mtb Pro. magazine...

+1 I remember the Answer Hyperlite bars were only supposed to be a ‘one season’ race bar or some such. Been hammering them for years with no issues but fortunately i never crash bikes ! Different story if they are exposed to that. My pref is for Ti bars, not quite as light as Alu but more damping, less prone to cracking like this and comfy to ride.

Handlebars and Helmets are two items I never take risks with. Replace both after crashing, never buy secondhand when you don’t know what’s happened in the past and replace frequently. Nothing can cause as much damage as a snapped handlebar or a faulty helmet.

How those could have been sold as anything other than a wind chime is beyond me, trying to charge £60 for scrap metal is just taking the piss.

Makes you wonder now about 2nd hand carbon bars or even seatposts, with de-laminating a possible concern, and it does separate internally so you cant see any outside problems, especially as overtightening would cause crushing forces to drive the layers apart.
Even cutting down carbon bars can split them from the cut ends in.

Oh well, back to steel with a brace

I lay blame at the bike industry, they've been quite sparse when it comes to the problems.

Il add rims to that list. As ex trade i have seen evidence of too many mishaps/close shaves, especially on commuter bikes. A rim can look low wear etc but if its been jumped, smashed into potholes a lot, it doesn’t take much for them to hairline fracture unnoticed, then suddenly split at an eyelet and jam the brake on.