Bicycle Mechanics - roadbike handlebars: fatigue, corrosion

What's the word on fatigue and corrosion limits if you want to avoid that dreaded scenario of snapping a handlebar at the worst possible time? Is it basically a wise idea to replace the bars every year if you ride a fair bit?

I don't often replace bar tape...so there gets to be quite a bit of white powdery corrosion under there when I do it. There were a few pits in the metal this time, but not as bad as I've seen before.

I've also accidentally discovered that wrapping the bar in duct tape before installing bar tape almost totally protects the bar from rusting. It must keep the sweat of it. I did this on one side only as I'd lost the rubber strip that fills the rear groove on the Ergo compatible bars, and filled it with a short section of empty cable holder/outer duct taped to the bar. When I went to replace the bar tape (MUCH LATER) I was pleasantly surprised to see almost NO corrosion compared to the other side. For the few extra grams of weight for the duct tape, I'll take the extra peace of mind and economy of bar life.

Of course, metal fatigue is still accumulating. But how serious a problem is that for average road bars? I expect super light weight metal bars may be more prone to failure in this regard?

And final question....CARBON BARS. Potentially excellent fatigue life, great vibration absorbtion, lightweight, won't delaminate or corrode on from sweat alone. The hood clamp could react with carbon and sweat tho? I don't normally spend $ on fancy stuff like this, but I'm wondering if even at the same weight as an alloy bar, if carbon bar offers more comfort, reliability and serviceable life?

Most companies that make light bars reccomend that you replace their bars once a year(assuming you ride a lot) or after a crash. I have Easton carbon bars and they ride very nice. They are all carbon and the only problems I have seen with carbon are when it is bonded to something else and even this is rare.

Trad bars have an external Al shim at the clamp. Modern ones tend to have a formed bulge. I suspect the older ones, whilst not as neat-looking, are mechanically more reliable. If the clamp bites into the shim or scores it, then the bar is safe.
The Cyclists Touring Club did a survey of bar breakage, and came to the conclusion that bars break mainly in France. Apart from that there seemed to be no pattern to the data.

The general rule of thumb is that you need to replace alloy bars, both mountain and road every 2-3 years depending on the amount of time you spend riding, or after a bad crash were they have been damaged. Light weight alloy bars need to be replaced every year like Rev. Chuck mentioned. That said, I have seen some people use alloy bars for more than 5 years without breakage. Seems to me though that doing so is sort of like playing hospital lottery. You don't want to be the unlucky winner in that game.

Chuck

That's kind of what I figured. Regular bar renewal could be the best insurance policy you'll ever buy. Like Chasbo said, if it does happen, it's highy likely you'll be visiting the emergency ward.

On a similar note, I was incredibly lucky when a steel threaded fork steerer broke years ago in the middle of a ride. First there was a strange sounding clunk, which must have been the main steerer section snapping, then about 1/4 mile later, the last piece that was attached let go...the bars went one way and the front wheel the other. Fortunately I was only traveling at walking pace at the time. The gods were smiling on me...I didn't get a scratch.

i have never seen a handlebar break... But i have seen a stem break... The rider ended up scraping the asphalt... Not very nice to look at... And sure feels................ it happens...