Destroying Aluminum frame?
 

The experts out there told me how Al frame will eventually fail dued to repetitive stress cycles but I don't know of anyone who had actually destroyed his or her Al frame from normal usage. But I know a guy who worked in the building cracked 2 steel Trek touring frames from commuting. So anybody got a story to share about your old Al biting the dust? How eventful/spectular was it? Of course, I'm not talking about destroying a frame in a crash.

Friend's Cdale failed at the junction of the downtube and headtube after about 20 years. Mostly due to corrossion from a lot of time on a trainer. It was pretty obviously a problem long before it actually failed.

Everything breaks sooner or later. Steel, carbon, aluminum, unobtanium, you name it.

A reasonably well-maintained and un-crashed aluminum frame will last a long, long time. As with any bike, inspect it for cracks every once in awhile and you should be fine.

What made them experts? You are not turning to the 41 for expertise, are you?

My 1987 Cannondale says otherwise! It's got a zillion miles on it, many of them hard miles, and is a rigid and stiff as ever, with no signs or cracks anywhere. (Now, granted, early Cannondales are really over-built. My seat-stays are massive compared to the spindly "engineered for compliance" ones that new AL frames have...)

Oh this thread again.... Steel rust; CF exploads; aluminum fails after 626 rides.

i see tons of 20+ year old alu road bike cruising around portland. not nos treks or cannondales either. these bikes are chipped, scratched, covered in mud and stickers, getting locked to parking meters and all sorts of other tough city living. i think aluminum is tougher then people give it credit for.

My C'dale M700, (purchased new in 1994), came with a loose page slipped into the manual, warning the owner to frequently check the headtube/downtube junction for cracks.

OMG! Aluminum FAILS? You mean the stuff that they make airplanes out of? The same stuff they are using in increased amounts in cars to save weight?

As already stated EVERYTHING can and does fail ... eventually. Most AL bikes are engineered way above what normal wear and tear can do to them.

I wrecked an aluminum CX frame a few years ago. A homeless guy jumped out in front of my path one day, on a dark, rainy, late winter ride. I wasn't sure the brakes would stop me before I hit him, and he froze up, like a deer in the headlights. I swerved out of the way, but in the process, I hit my chainstay against ... I can't remember, it was a sign post or a fence or something. Yeah, rider stupidity was involved.

I probably hit the stay going about 5 mph, but it dented. Two bike shops told me the frame was toast. It cost $400 to replace it. Took a month, too, and it was a crappy month without a bike. :(

Of course, who else should I turn to? Perhaps I should stated "self-proclaimined experts on 41".

Al can handle fewer stress cycles than steel/ti/carbon.
I've seen several failed, usually crack at bottom bracket.
I've also got around 13kmiles on mine, with no issue.

It's irrelevant, some last some don't, depends on design and manufacturing deviations.

I wouldn't sweat it.

'''Fatigue limit, endurance limit, and fatigue strength are all expressions used to describe a property of materials: the amplitude (or range) of cyclic stress that can be applied to the material without causing fatigue failure.[SUP][1][/SUP]Ferrous alloys and titanium alloys[SUP][2][/SUP] have a distinct limit, an amplitude below which there appears to be no number of cycles that will cause failure. Other structural metals such as aluminium and copper, do not have a distinct limit and will eventually fail even from small stress amplitudes. In these cases, a number of cycles (usually 10[SUP]7[/SUP]) is chosen to represent the fatigue life of the material.""

http://en.wikipedia.org/wiki/Fatigue_limit

Mathematically then, at a cadence of 90rpm for 200 miles per week at an average speed of 20 mph your bike will fail in 17.8 years. Longer if you ride less. Beware.

The suggestion that "all aluminium frames eventually break", in my opinion, gives the incorrected impression to the uniuninitiated that they will all (or most) break after a 'handful' of years worth of hard riding. Sure, they break, but they many don't, and lots last for many years. In other words, the notion of 'all alu will eventually break' overstates the amount of cracking alu frames out there.

I've been thrashing, mashing and crashing various alu frames for well over ten years (including 'good' ones and cheap Asian ones), and I've only cracked one, which was a 1999 Specialized Allez Comp. It developed a fine, hairline crack under the bottom bracket, which I only spotted because I was cleaning it, and noticed the suspicious crack in the paint.

On the other hand, on my steel bikes, I busted the right dropout on my old Raleigh twice, possibly from hopping curbs. :p

That's why everyone in the San Gabriel Valley rides steel, carbon, or Ti.

If your stable is properly equipped, you should barely notice if you are a bike down for a month...

Are you asking our opinion on the longevity of aluminum frames? Or are you trolling for horror stories?

Not welded together, but epoxy bonded..

AlAn the Screwed and Glued design showed head tube cracks in the "Lugs", over time.

easily repaired , in Italy... But getting it there, & back, from the US was costly.. :notamused:

I have two broken aluminum frames in my garage right now. Neither failed all that catastrophically. One is definitely unrideable, and the other I wouldn't feel safe riding.

Felt F35 that cracked right at the RD hanger.

http://i.imgur.com/7JEjgl.jpg

http://i.imgur.com/NezW6l.jpg

~2000 GT aluminum that has cracks on the headtube.

http://i.imgur.com/BFBQ6l.jpg

http://i.imgur.com/8oAYJl.jpg

http://i.imgur.com/YsxCfl.jpg

Head tube cracked on my Specialized Allez Elite. I was second owner so no frame warranty. :-(

In fairness to AL, I cracked the bottom bracket shell on a Italian steel racing bike but that frame was saved by brazing.

I ran my CF bike into a telephone pole at a good clip (about 15 mph) a bit over a week ago and it came through unscathed.

So far, it's CF 1, AL 0, FE 0. :-)

If it's a de Havilland Comet, I'd be concerned with catastrophic failure. Otherwise, no.

Sweet jesus. What about you?

fify

I can remember cracking my aluminum baseball bats when I was in Little League.