Aluminium frames...good or bad?
 

So I have one road bike, my steel 1984 Nishiki and I bought a 2006 Trek 1500 yesterday. Today when buying some bar tape at Bicycle Sport Shop the tattooed hammerhead says "aluminium frames crack...I know from first hand experience" implying that I should have bought a carbon frame bike. Sure they had some five and seven thousand dollar bikes there. I paid $250 for the Trek. Now I have a Trek 8000 and a Stumpjumper FSR and I've punished those bikes on trails for years and they never have cracked. Do any of you have any experience with aluminium frame road bikes cracking?

Mine haven't!
My aluminum MTB is 14 years old and has been through hell!
My aluminum road bike is only 3 months old.

Carbon fiber bikes crack too. The thing with aluminum frames is that they are supposed to be more prone to the material fatiguing as they get older. I have had several aluminum road and mountain bikes and have never had a problem. If you have looked the frame over really well and not found any signs of stressing or cracking then it is fine.
Several years ago I bought a ten year old aluminum trek, rode it for about 10,000 miles and then sold it on to someone else who is still riding it.

Aluminum bikes do crack. Carbon also cracks, and shatters. Steel can bend or dent. Any number of bad things can happen to any frame material. Just pick your poison and enjoy the ride. And try not to crash :)

I have taken my CAAD 9 on downhill MTB trails and single track trials. Both the aluminum frame and carbon fork are ok.

Aluminum is fine. I dont think I ever read a post where somebody has cracked a seat tube or a steerer on an aluminum bike/fork from over tightening. Carbon asplodes if you look at it wrong anyway :)

All of them can crack but are not likely to. You got a good deal on your bike, enjoy it.

Sure it can crack, so can Steel and carbon frames...... will it, I doubt it. I've seen plenty of steel frames bent, dented and cracked but never an aluminum frame. The guy's a moron.

It can crack, but will it? Who knows. I don't like them because the ride quality feels weird to me, but that's just me.

Aluminum!?! :eek: :eek:

Cracks! Fatigues! Harshness! Corrosion! Locust Plagues! Enlarged Prostates! Toenail Fungus! Aluminum!!!!!

Only poseurs that are too cheap to buy Carbon or better yet lugged Steel or better yet Titanium ride aluminum. Walmart sells Aluminum bikes!!!!!

GEEZE! You bought ALUMINUM! If ONLY you'da asked!!!!! Awww, Man!!

Yup--aluminum airliners crack and fall out of the sky every day. :eek:

LOL. You listen to what your told at the LBS? From a guy who's talent and career aspirations has taken him all the way to the cash register of a LBS?

By all means possible, dump your Al bikes immediately and buy a CF Giant.

Do not ride an aluminum bicycle; get rid of it asap.

It is absolutely certain that it will suddenly break on you, causing serious personal injury. In the meantime, were you to ride it up to the point where it catastrophically fails, you will cause yourself untold harm; you will permanently injure your spine through the excessive jarring caused by aluminum frames, and your hands will fall off as a consequence of excessive vibration.

ERs across the world are full of cyclists seeking treatment as a result of riding bicycles with aluminum frames. The major bicycle companies are spending untold millions defending product liability suits and at the same time conspiring to keep you, the poor consumer, in the dark about the evils of this frame material; it's a wonder any of them are still in business.

I know all this to be true; I read it on Bike Forums.

My CF Merckz cracked because I parked it next to an aluminum bike. They are just that dangerous.

I read some messages from people who rode touring bikes and some have said that handlebars, seatposts etc. broke over time but I can't remember messages about cracked frames. I vaguely remember one post with pics though.

You need not worry about your AL frame. Every frame material can crack or fail (although titanium is bloody TOUGH). I have been riding aluminum for years and have never had one fail or even crack. The person who told you that is like some of the members here.....lots to say but nothing factual.

Ride your bike and don't worry.

In my experience most of the frames that come into bike shops with cracks are aluminum. I suspect that aluminum is somewhat more prone to cracking than steel. But I also suspect the increase in failure rate is so slight as to be worth ignoring.

A somewhat more pressing problem, IMO, is that aluminum tends to fail suddenly whereas steel tends to bend first. That makes me nervous, but again, is probably too small a concern to actually worry about. (Carbon, of course, fails suddenly and catastrophically too, so choosing carbon instead of aluminum because you're worried about cracks is stupid.)

Oh, and mprelaw? Airplanes are subject to stringent and thorough inspections because of aluminum's propensity to crack and fail. So that probably wasn't a very good analogy...

After tens of thousands of cycles of pressurization and depressurization. Any one of which puts more stress on an airframe than a bike will experience in two lifetimes. It's not the "propensity" of aluminum to crack and fail, but the propensity of any metal to eventually fail after many, many repeated instances of expansion under pressure, and relaxation after depressurization. Metal fatigue in aluminum airframes wasn't a concern until pressurized cabins became a reality--Google "DeHaviland Comet". More stringent and frequent inspections after a certain level of cycles (a 5 figure threshold) became required after the cabin roof tore off a 737 in Hawaii---it had over 90,000 cycles of pressurization on the airframe when it failed.

nah they are great
stiffness means efficiency
period

wle

That new carbon jet liner had cracks....in the aluminum joints.....just sayin....

It's all about design, boys, all about design.

And that daggone aluminum is only good for beer cans, so.run.away.

That was quite strident, but doesn't actually contradict what I wrote: Commercial aircraft are subject to frequent inspections because the material they're made from (aluminum) is known to crack and then fail catastrophically. So it's not a good analogy.

Titanium is best.
There's a reason they built the SR71 out of it.

;)

These days, aluminum frames are probably the most common material out there for bikes. It is therefore most reasonable to assume that most cracked frames are going to be aluminum, due to the number of them on the road. People also tend to treat the higher priced carbon bikes with more care than they would the cheaper aluminum frames, making it even more likely to see aluminum being broken more often.

I don't subscribed to the theory that aluminum is a weak material for bikes. I see a ton of them on the road with no problems, and I myself have an aluminum bike that I put most of my miles on. I'm also a bigger guy (6'5, 230) and put the bike through a lot of stress with no problems at all through many years of service.

F*** what ya huurd. Al is bomb proof. (as long as the frame tubes aren't tack welded to one another...)

They all crack if you crack them. Some materials crack better than others. Walmart aluminum is probably the best crack for the buck.

It all depends, however, it's important that you don't get involved with crack.

I personally dig the spring.

My Stumpjumper hardtail is an AL frame & its nearly 10 years old, still looks like it almost new.
I'm was pretty hard on her, but I made sure to maintain her too.(retired)
My Opus is also AL, I hop curbs, & take jumps on concrete @ 15-25 KMs.
There's this one route I take when I go hard on climbing, & sprinting.
@ one point there's a small bridge where the drop is about 2.5-3", I just jump it cause I don't want to slow down so much to"roll" down it.
Is this good for my bike? Probably not but she takes a kicking, & keeps on ticking.
Is my bike meant to do this? Probably not, but its a Cyclocross so it should she able to take these bumps, & jump
Speed 20-25 KMs/ my weight fluctuates between 145-155 lbs/ 2.5-3" drop = ???
Glad my tires can handle the abuse.

Did you ride you BMX when it was all rusty? I know I did as a kid.
Did it even fail on me? Nope.

Yes.

Although your assumption may be correct, the comment is valid. The assumption is not.

I've cracked a few aluminum road frames - an older Cannondale, a Specialized M2, and a Giant TCR.

There's the concept of pushing the limits with materials. If you build something so that there are no failures then you've overbuilt it. At the same time you want to have no failures in certain parts, so, for example, I'd consider a fork, bars, stem, and steerer to be the "no failure" parts of a frame/fork.

All my frames failed in the chainstay, about the safest place for a frame to fail. None broke through. I rode all of them for a while before replacing them (a month or two). Other than some creaking, some tire rub under pressure, the frames were rideable (and raceable). In all three instances I didn't know the frame was cracked until I happened to find the crack (or a coworker did).

I've also seen some amazing steel frame failures, the most incredible a Pinarello whose top tube cracked in half. The ride noticed something wrong in the last lap of a race when his bike felt "bouncy". It should have - you could push the saddle down a good 2-3", until the bowing bike's cranks almost hit the ground.

I broke a ti axle BB (the right arm came off, reminiscent of Fignon's Campy SR ti axle failure). All materials have their limits and design limitations.

I happen to ride aluminum frames. I'd ride carbon (have in the past) but custom carbon is too expensive. Fit > Material.

They make bombs with aluminum. Also with CF. Aluminum AND CF therefore explode. Stay away from Aluminum. And don't spend much time above ground - those Al airplanes that fall apart in midair might land on yer head.

Wonder where this thread will go....:popcorn