CaptainPlanet

I heard mentions of aluminium fatigues in welds here and there, but the opinions are pretty mixed even in several bike forums. If bike condition looks to be okay on the surface level, is it still safe to ride? It won't just tear apart half way on the trip I hope?

Bigbus

Jeez, lets hope so... All metal is subject to stress fatigue, but how you stress it has a lot to do with longevity.

alo

Yes. 10 year old aluminium bikes are safe to ride if condition looks okay.

70sSanO

I'm still riding a 1986 and 1988 aluminum frame bikes. There should be some caution with 30 year old bonded aluminum frames if there seems to be oxidation around the lugs. But unless the aluminum frame has been abused and left out in severe weather for the past 10 years it shouild be fine. You can look at the welds to make sure there are no obvious cracks.

John

Retro Grouch 

Short answer is aluminum bikes are safe.

1. There are a lot of aluminum framed bicycles in use. Everything has a failure rate but if aluminum bicycles failed at the rate the aluminum haters talk about you wouldn't have to ask the question. Failures would be so commonplace that you'd know.
2. Ever fly in an airplane?

cb400bill

My 14 year old aluminum Cannondale has well over 20,000 miles on it.

sch

One might inquire more closely about past use/abuse IF you are considering an ATB or downhill frame. Road
frames, pretty much as above. Generally good for upwards of 100k miles or more.

fietsbob

Sight unseen? You have to send me a waver of liability, notarized before I'll offer an opinion /,,

I own a bike made of 7005, T-6 .. It was made half way around the world from here in 2004..





..

Andrew R Stewart 

One big difference between air planes and bikes is the maintenance schedule planes are suppose undergo and that inspection abilities are designed in (especially for commercial aircraft). Inspection during construction as well as during the use. If bikes were so well tracked by people who know their stuff we would have much less JRAs and also less need for this forum.

Al has the unfortunate nature to develop cracks and have the cracks grow rather quickly (compared to steel). Having said that most of a frame's members are connected at two ends, as in a tube being attached to two other tubes. So a unseen crack that is allowed to grow and thus results in a complete break won't cause as great a structural stiffness loss in many cases. Not saying that a cracked and broken tube should be ridden any longer then it takes to stop... A significant exception is the fork, wonder why there are so few AL forks of light weight design? Al steerers are of the highest risk of injury if they fail. Brake cables/hoses make for great retention leashes but are poor structural members.

To get around this shortcoming Al frames tend to be stiff enough to not bend much as to not then cycle up their fatigue cycle curves to soon, made with thicker walls to reduce the cracking possibilities, made without welding to reduce the heat induced issues and the after construction aging/heat treating to regain full strength and have somewhat limited life spans by warranty coverage (note that many forks are no longer considered a frame part but a component).

So ride your bike but as Regan said "trust, but verify" Andy

alcjphil

Any properly designed aluminum bicycle frame will last a very long time. That said, the only aluminum bicycle I have owned, a dual suspension mountain bike broke both the main triangle and the rear chainstay. This was not a low end bike, rather it was a close to top of the line model, close to $3000 when new. I was able to replace the defective frame parts, albeit at my own expense, and I am still riding that bike to this day. Mine was not an isolated event, it was a result of a very poor manufacturing run, almost bankrupted the company

AlmostTrick

Yes. It's not like carbon fiber which can have hidden damage/defects that you can't see.

easyupbug 

I think that the consequences could be serious of an unknown crack propagating but the likelihood very low to de minimis if you will keep an eye on things.

CyclingFool95 

Aluminum fatigue failure shown above.

Aluminum is more prone to fatigue failure than steel or titanium. Aluminum is more prone to cracking and having cracks propagate. Any material can be overloaded and suffer damage, perhaps more likely if the design pushes the envelope in the interest of, say, weight. Personally, I'm more comfortable on a steel or titanium frame - I have no concerns about any of my 25+ year old bikes. I do, mind you, contemplate the state of the equally old bars and stems on those bikes and worry about those.

shelbyfv

OP, if you'll post what bike you have, folks may be able to tell you if it has any unusual history of failures.

Myles Quarter

As long as its in close to factory shape I think you should be ok!

Ross520

I sure hope so, because my gravel bike frame is 27 years old and looks questionable at best. 😂

DiabloScott

Any 10-year old bike you are considering purchasing should be inspected very carefully for damage and cracks.
Aluminum bikes are not more prone to fatigue failure than steel bikes. All fatigue starts with a crack. Crack plus cyclic stresses = fatigue failure.
Aluminum has the unusual material characteristic of developing fatigue cracks without being damaged - either in production/welding or in use. A quality frame design will have accounted for this, a cheap one maybe not.
Steel bikes that have been damaged in production or crashed can have a crack which will cause fatigue with continued normal use.

I would not consider buying a damaged frame.
I would not consider buying a 10-year old budget frame.
I would not hesitate to buy an undamaged 10-year old quality frame of either steel or aluminum.
And my No.1 road bike is 22 year old aluminum.

FastJake

Any frame made from any material can break and should be inspected for cracks by eye. The last broken aluminum frame I saw was a ~2000 Trek 8900 that slowly cracked and failed where the chainstays meet the bottom bracket.

Seriously? These are some of the stiffest and most over-built frames ever made. Those and the loony double-oversize steel frames with thick walls.

A high end aluminum frame might be more likely to fail with the focus on lightweight and therefore less material.

Amt0571

Yes. They are.

As long as the frame is free of cracks or dents, I see no issue to ride a 10y/o frame.

In fact I recently replaced my 10y/o mountain bike after more than 30.000km and I sold it to my uncle who keeps riding it with no issues.

I would ride a 20y/o frame without worries if it was in good shape.

DiabloScott

Budget frames also have the poorest weld or brazing quality, exactly the places where hidden cracks start.
But yeah, truthfully I wouldn't consider buying any budget frame,,, because I deserve the good stuff.

Gresp15C

Any second-hand bike needs a full inspection. Whether there's likely to be a problem has more to do with how the bike was treated than the materials of the frame. A cruiser or hybrid in good cosmetic condition? I'd still inspect it, but not be too worried about it. There are aluminum bikes in my family fleet that have simply never seen hard miles or off road conditions. The only breakage I've ever experienced was a steel frame -- one of the fork ends broke off.

pattrick

I have a 2000 aluminum Jake the Snake I run as a night bike/ foul weather bike. The bike seems to be fine? I have put this thing through hell and back and it has never faltered. It has never shown any signs of fatigue I or the local bike shop can verify. It still rides wonderfully and brings a smile to my face despite it's age. While I can not tell you for sure when an aluminum bike will fail, I can assure you mine is still quite nice after twenty years despite the abuse. We won't even discuss the two deer it's hit. Lemon Pledge and the occasional touch-up paint is the only attention it has received and it still looks sharp, at least in my eyes. The shop I deal with sells Konas and will often show my bike as an example of these bikes and their durability.

Andrew R Stewart 

We've seen quite a few Al frames with cracks, more then a couple a year average. Most common is the headtube cracking along the tube axis from either face. The headset reaming might be suspect but most of these cracks are pretty close to the TT or DT welds although generally not at the root. The next common is probably the chain stay, drive side of course. Usually pretty close to the BB weld root or the clearance dents. A very few DT around the HT weld, root is the likely sources. Other locations are so few that there's no "average" in them IME. Thankfully the cracked forks have been VERY few, actually don't remember the last one.

As to the bikes' grade that have cracked most have been road bikes of Asian production and not very expensively. The exception seems to be Bianchi with a few chain stay cracks on their nicer bikes. (Flamers and lawyers can find me easily...)

While our sample size is not large (thankfully) we are known in our area as a service focused shop and often see other shop's issues when they don't handle things well enough for the bike owner's acceptance. Andy

sweeks

I have a Trek 6000 which I purchased in 2000. This bike has seen a lot of miles of gravel trails, singletrack and some abuse (finished the Ore-to-Shore in 2001). It's still in fine condition.