You might be better off to ask about a particular bike frame.

If you don't crash it, should not break. At least within your mortal lifetime.

I've seen guys around here with 10 year old CF bikes who actually rode them regularly, and they looked brank spanking-new, without being particularly babied. Just no crashes or falls.

I wanted something lighter (Ti) and also wanted to upgrade from down-tube shifters and 6 speeds in back (dura-ace 7400) to brifters and 10 speeds in back. The old one is really fine though.

He's a mod, he can ask anything.

It's ok, he's one of the good guys.

I commute to law school on the steel Mexinelli Windsor Profesional (sp) that my dad bought in ~1974. It has fenders so I also use it as my rain bike.

Did the STP last year on my dad's steel Tommasini he bought in 1991.

Finally test rode some new CF bikes Friday and, even though they don't have the classic style of a handmade Italian steel frame, I still have new bike lust.

You have to be kidding. Have you ever ridden a titanium frame.

Well, you started a thread about frame materials and didn't return comments for 3 hours. Just looked a little suspicious at the time, troll-like.

It's ok, carry on.

The technical stuff is probably over his head.

It's not weird that people would think that when Grant P. writes it over and over. Maybe he's right. I don't know.

None of the 3 frames I posted pics of were crashed, only one if them was mine, however. I've also broken 3 other frames that were never crashed.
Any frame can break, a woman I ride with has broken 2 cf frames without crashing.

Actually, I am a mechanical engineer, so I know a little bit about materials. Was just wondering what the common modes of failure are for frames.

Thank you for your concern though--it was very thoughtful.

Bull****. Like most of yer stuff.

Which part? That I'm an engineer, or that I thought you were actually being thoughtful?

It is a 1998 GT Edge Aero frame. Anyone have any experience with those?

BF member Rick@ocrr has a couple old GTs and he rides them a lot. I think they are older than 1998, though.
Any bike can last a long time but any frame can also fail unexpectedly.

Metal frames actually last longer with a heavier rider because their bigger bodies absorb more metal fatiguing resonance.

trollface dot jay peg

Lugged steel frames are basically infinitely repairable. "Yeah, it's had the main triangle replaced twice and the stays replaced once, and I think that's my third or fourth fork. But it's still the same bike!" I suppose that's true to some extent for someone somewhere.

Oh wow another mechanical engineer amongst us. About 90% of our membership are engineers of some sort. We are so blessed.

Last steel frame i had lasted 11 years before the chainstay snapped due to corrosion + fatigue.

Frame before that was steel and outlasted the chromo fork which folded after about 5 years.

Last weekend I went head long into a car on my alloy Allez at 22mph, the carbon fork generated enough bending moment to tear the headtube off the top tube. The carbon fork looked new afterwards. That frame was 5 years old.

I have a cabon bike too - i will cry if i ever crash it, if i dont i expect it willl last my lifetime.

The avarage bike in my experience lasts 5 - 10 years because thats how long it takes me to break it regardless of material, make, model or workmanship

No Nick.

The OP asked about frames but frames are just part of the equation. I have never broken a frame but I have broken a lot of other parts. The consequences can be huge. If a fork breaks you're going to crash. I have a friend who has broken two Dura Ace crankarms and crashed both times. I have an old steel frame with about 50,000 miles on it without incident. In that time many other things have worn out or broken. It has had three rear wheels, two front wheels, two rear derailleurs, two bottom brackets, three saddles, three front shifters and a lot of chains. I have not replaced the bars or fork or crank or bottom bracket. Maybe I should? We should be able to know the normal life span of a bicycle, especially with lighter stuff, because these are vehicles that people rely on with their lives. I wouldn't expect a bike to last forever with heavy use but what is reasonable? What is the trade-off between light weight and longevity? What would the lifespan be of a 15 pound CF wonder bike compared to a 20 pound version? Should my friend dump Dura Ace and start riding 105? Bike companies with REAL ENGINEERS should be required to issue guidelines. I realize that most BF members are highly-qualified engineers (you can tell by reading the posts!), but shouldn't the engineers at the bike companies be calling the shots and the companies take some responsibility for the products they design and make? It's OK for things to wear out and eventually fail. It's not OK for bike companies to pretend they don't, especially when the most expensive and lightest products are used the most, and arguably have the shortest lifespans?

I recently had to replace the stem on my Jamis. I noticed a hairline crack in the bracket where the bolts were. I only noticed it after glancing at my computer before going on a ride. I bet these types of failures like Jaznine said above are more common than frame failures.

I dunno how long they really last, but I'm pretty sure now that my latest bike hit 5K miles it's time to ditch it and get a new one. Why take a chance on an explosion!?

Well, all of it. There ain't nothing technical in this thread. Every thing that is in this thread is just all sort of anecdotal and hearsay. You are the engineer (so you claim) - can't you find information on material fatigue? I think you are just trolling to get a steel vs. crabon vs. Ti vs. AL vs. BS arguement. Is what I think.