|Tell me about handlebar replacement||Fez|
Dec 17, 2003 7:35 AM
|I did read the recent posts about Doug's client and how his bars broke.
Made me wonder about NON lightweight aluminum handlebars and when to replace. Assuming it passes visual inspection (looks true, no visible cracks), what are the signs that it needs replacement?
Are most failures sudden and catastrophic, or do you get a little warning via noise or flex before they shear off?
As for me personally, I have relatively heavy 3T Forma bars that used to be silent but have picked up a faint noise recently when climbing. Its *not* the ticking sound commonly heard from the stem clamp.
Do I replace immediately, or do I get a progressive indicator that the bars are wearing?
P.S. Bars are only 2 years old, never been crashed, have only 6,000 miles and I am very gentle on equipment.
|re: Tell me about handlebar replacement||PaulCL|
Dec 17, 2003 8:05 AM
|Two years old, 6000 miles....I wouldn't worry about it. My secondary bike has a 7 year old bar with >20,000 miles on them. They are heavy ITM AL bars.
My LBS owner really chided me for riding older bars as in "you're putting your life into jeapardy" speech. He's probably right. Currently I am scanning EBAY for a new set of cheap bars. After seven years, a couple of minor pavement surfing incidents, and my 185+lbs of torque on my KY hilss...its' time to replace.
Rule of thumb: If you hit the bars during a crash - replace them. If you're a big rider who torques them alot on climbs -replace them after a few years. Non-CF bars aren't that expensive ($40-60). So, like a helmet, better safe than sorry.
|I got torched on this a few months ago ...||pmf1|
Dec 17, 2003 8:55 AM
|In describing how much I like my carbon bars, I noted that they last longer than alauminium bars which should be replaced every 2-4 years and are therefore worth a bit more in that regard.
About 25 people jumped in and told me what an idiot I am for replacing bars and how they've ridden the same bars for 50,000 miles blah blah blah ...
Would I replace my bars after 2 years an 6000 miles? No, probably not right away, but I'd start thinking about it.
|I got torched on this a few months ago ...||rogue_CT1|
Dec 17, 2003 9:41 AM
|pmf1- I may get torched too but... I have to agree with you. I change my Al bars every year no matter what.
Three factors influenced my decision on this-
1) TTT's instruction manual advises to replace the bars every year or two depending on riding conditions. eg-racing
2) I experienced a stem failure while I was riding. I don't want to relive another catostrophic failure in the stem/bar/fork area.
3) I witnessed a friend crash at 40+ MPH on a decent. I don't want to have it happen to me.
With these three factors in mind, I see new bars as cheap insurance against a dangerous or deadly crash.
That is MY opinion- everyone else needs to make their own decision.
|I got torched on this a few months ago ...||pmf1|
Dec 17, 2003 1:11 PM
|Its kinda like those guys you see riding around without helmets. I always fight the urge to ask them if there's anything under their skull worth $50 to protect.|
|Can aluminum corrode...here's a story||filly|
Dec 17, 2003 8:30 AM
|Disclaimer: I don't know 100% of the details...
but, a friend of my dad's was riding his < 2-yr-old 5200/5900 and snap, he went flying forward, destroying his bike. Bike was a loss (it took down others as well--I think this was how his bike got trashed). He looked at the bars afterwards and noticed a white powdery substance under the tape. He works at a chemical company (Dow), and some guys at work who would know such things said that substance was basically the equivalent to rust on steel. It was an indicator that the aluminum was corroding. *I thought aluminum didn't corrode?* Anyway, this incident happened in Louisiana. If you've ever been here and ridden during the summer, you know that you sweat buckets. Apparently, the sweat had built up enough over the season, remained trapped under the tape, and it just ate away at the aluminum. Then one day, snap.
Does this sound right? Aluminum corroding?
|Just found it...yes, aluminum can corrode (nm)||filly|
Dec 17, 2003 8:40 AM
|questions re corrosion||DougSloan|
Dec 17, 2003 8:54 AM
|1. Could the powdery substance have just been salt from sweat, not necessarily any indication of corrosion?
2. Can painted or anodized aluminum corrode? Most all aluminum bars now are black anodized, aren't they?
|taken off the net...||filly|
Dec 17, 2003 9:06 AM
|Information collected over the years from manufacturers and users has shown that aluminum structures will provide reliable service for periods in excess of 30 years. The factor which assures the long life of aluminum is its self forming microscopically thin surface layer of aluminum oxide. This layer is so thin that it is measured in atomic units. The air-formed film on new aluminum surfaces is about 2.5 nm thick, while the film on aluminum that is several years old may be 10 or more nm thick. The film is composed of two parts:
A thin, inner barrier layer
And a much thicker bulk outer layer which is more permeable than the inner barrier layer
Chemically, the film is a hydrated form of aluminum oxide. The corrosion resistance of aluminum depends upon this protective oxide film. which is stable in aqueous media when the pH is between about 4.0 and 8.5. The oxide film is naturally self-renewing and accidental abrasion or other mechanical damage of the surface film is rapidly repaired. The conditions that promote corrosion of aluminum and its alloys, therefore, must be those that continuously abrade the film mechanically or promote conditions that locally degrade the protective oxide film and minimize the availability of oxygen to rebuild it.
The acidity or alkalinity of the environment significantly affects the corrosion behavior of aluminum alloys. At lower and higher pH, aluminum is more likely to corrode but by no means always does so. For example, aluminum is quite resistant to concentrated nitric acid. When aluminum is exposed to alkaline conditions corrosion may occur, and when the oxide film is perforated locally, accelerated attack occurs because aluminum is attacked more rapidly than its oxide under alkaline conditions. The result is pitting. In acidic conditions, the oxide is more rapidly attacked than aluminum, and more general attack should result.
|I've seen old sailboat masts that corrode||Dave Hickey|
Dec 17, 2003 9:08 AM
|Mast and other aluminum boat parts are anodized and I've seen many corrode. Of course they spent years in a salt water enviroment.|
|"white rust"...taken from the net||filly|
Dec 17, 2003 9:16 AM
|This is taken from a site that sells shower doors...
When you use harsh abrasive cleaners or steel wool, you cause the protective anodized coating to break down. When this happens, you will lose the shiny coating and the bare aluminum will be exposed and, as a result, will corrode. This corrosion is sometimes called "white rust" because it looks like white rust. While "white rust" is not pleasant to look at, it will not affect the durability or safety of your shower enclosure. Removing "white rust" once it appears is not easy. It is best you prevent damage of the aluminum by taking care when you clean your shower enclosure by using a nonabrasive cleaner (like comet Nonabrasive Bathroom Cleaner) and a soft, damp cloth. This will help protect the anodized coating and prevent corrosion of the aluminum.
|re: Tell me about handlebar replacement||MShaw|
Dec 17, 2003 9:18 AM
|General rule of thumb: replace helmets and handlebars every 3-5 years or so.
Better safe than upset!
|OK, OK, lets refocus...||Fez|
Dec 17, 2003 10:18 AM
|What I am mainly wondering is whether the handlebar does fatigue, absent any visible cracks or crash damage.
And when they are about to break, is it a sudden and catastrophic situation, or is it gradual and progressive?