Road Cycling - aluminum frame?

I just read an article in a book ("Ultimate Bicycle book" by Richard Ballantine). it says;

"...Aluminum has no fatigue limit, so each and every stress causes wear and weakening, and eventual failure... Even if well-worn a steel or titanium frame will stay almost as good as new, but not aluminum frames, whic are thought to have a useful life of 3-5yrs..."

The article goes on and said that the life of most steel or titanium frame is measured in decades.

3-5yrs seems short. I thought aluminum frame could last longer than that even with a little abuse and daily ride.

This article's kinda discouraging. I've been thinking about getting Raleigh R700 frame, which is made of butted 7005 aluminum. But I'm still planning to get it, because it looks cool. I think it has one of thickest aluminum bars for a road bike.

btw, what's the deal with all this numbers in front of aluminum, like 6065 or 7005? Anyone?

Just wanted to share that with you. Any thoughts?

I have an aluminum Schwinn frame that is over 10 years old and was not taken care of. I beat the hell out of the bike in 2 years of commuting (after the bike was my regular ride for 3 years and then sat in a dank basement for 5 neglected years). The frame is still rock solid, if not a little scuffed and scratched. The 3-5 years sounds suspect to me, but I don't really know.

As far as tubing, here is some info from Easton Easton Frame Tubing (http://www.eastonbike.com/tubesets_top.html)

It is true that Al will fatigue if you bend it. Thats why good Al frames are made with fat tubes, to build a stiff structure. The structure will prevent the material from bending. A high quality Al frame, such as Cannondale or Principia has an extremely long fatigue life, and have, in tests, outlasted several fine Italian steel frames.
All frames suffer from fatigue. Poorly designed or built frames in steel or titanium can crack, usually at the chainstay or a braze-on.

hirochun,

Since I am not an expert on frame materials, I will leave the question regarding 6065, 7005, Optimo or other aluminium alloys to this forum's metallurgists.

In general, I would not worry too much about the durability of any of the commonly used frame materials (with perhaps the exception of--obscure--carbon?). As MichaelW says, a sensibly designed and well built frame can take a beating, regardless of the material. It is likely to outlast the life span of all the other components--and even that of its owner's 'commitment'.

Many of us have (ab)used alu bikes on a daily basis for many, many years. Yet reports of breaking equipment (under reasonable circumstances) are rare (or hearsay stories). I haven't searched for it, but there might be a 'Have you broken your bike lately?' thread on one of the forums...

When I was 'researching' frame materials (and eventually ended up settling for titanium), I encountered a lot of scientific, laboratory-like figures, graphs, etc. in favour of one or the other material. Not that these 'data' are false per se, but in IMHO they are usually more relevant as selling arguments. 'On the road', other factors (geometry, construction, comfort, componentry, etc.) probably put more weight into the scale.

My neighbor has been building race cars and race engines for 30 years for Pro drag racing, even NASCAR. I talked at length about frame material since I weigh 260 and was concerned about an aluminum frame. He basically laughed at the critics. You have nothing to worry about.

100% of all aircraft today are made out of aluminum.

Next time you take a flight sit over the wings and look out the window. You will freak when you see those wings boucing up and down about 1' either way. Look like they are flapping!!

I would say if aluminum can take the stress of flying 100,000's of miles, then it should last a good long while on a bicycle. Which I don't think flexes nearly as much as those wings!!!

You have to take these articles with a grain of salt.Racing vs long rides vs short rides vs dirt vs size of rider all make for differences in frame life.If you dont race or do dirt,i wouldnt worry to much about it.

What if an aluminum bike is crashed? Will it fall apart?

No more or less then the rider,LOL

Obtaining different points of view is a good thing to do.

Now pull up the Klein bikes webb site for an opposite opinion. Gary Klein will make you wonder why anybody builds bike frames out of anything other than aluminum.

Man, this comes up entirely too often. Yes, it is true that aluminum lacks a fatigue limit. The reality is that it is highly unlikely that any of us will be able to cycle a frame often enough and at sufficiently high stresses to cause the frame to fail due to fatigue. If you want objective information about how high these stresses would be, check out a materials engineering textbook. It's pretty interesting stuff.
As for the numbers, 6061 is the most common of alloys used in bicycles. 7005 is yet another popular alloy, and Cannondale's Optimo is an Alcoa variation on 6061.

Thanks for replies guys.

2k2s4 – sound like you had that one long time. Hope mine last long too.

MichaelW - I actually have been thinking about buying an old Italian steel frame bike, and install new components just for the fun of it. And see how well it compares with Al frame bike.

Bruco & Waldo - I don’t remember seeing or hearing any broken frames either. Oh, there’s just this story, I heard the other day from an old guy (about 50yrs old). It happened to him about 30yrs ago. He was riding his steel frame bike downhill fast. Suddenly his steel fork broke and the front tire rolled off to the side. As he saw the front tire rolling past his side, he could think of only one thing “dug”. So he dug his head and made his body as flat as possible holding the handles as tight as possible. And the fork hit the ground and the bike and he flipped. He landed on his back hard. He survived with few scratches. After that he said he never rode bicycle again. Sad sad story. So it’s not a broken frame story. But I learned that steel can break. I’m sure over the years, they have improved equipment qualities.

Itschris - you know that’s reassuring. I’m about 200lbs myself. Once in a while I worry it too.

Msparks - I’ve seen it, and it really freaked me out. It still does. And I agree with you. But I’m kinda confused though, about fatigue limit and taking stress. The guy who wrote the article says that Al don’t have any fatigue limit. Doesn’t that mean that Aluminum won’t return after flexing it? Maybe I misunderstood the word ‘fatigue’.

Shokhead - I feel much better now after reading your replies.

Smelly & shokhead LOL

Spoke Wrench I went to Klein bikes website. I liked their frames, even though their mostly aluminum. I’m still after R700 frame, because of its look, and big bottom tube.
:D

Hey, hey watch that "old guy (50)" stuff! ;-) lol

I have a Raleigh Competition and am extremely satisfied with it. (It's the successor to the 700) I have put around 200 miles on it so far and the the ride is great.

I have a 1982 C-Dale that I rode until '99, no problems. I have a '94 M800 C-dale that has been used hard off road and for trials withno problems. The cranks on almost every bike running now are alluminum and They don't seem to fail to often.

If the bike is designed properly then it will be strong and should last a long time. Particularly Cannondale's Plenty from the 80's still running around here.

I have a raleigh technium from the early 80's that I still race, it has well over 25,000 road miles on it and has been re-fit every 3 years with a new build kit, the main frame triangle is aluminum and is in a like new condition, the bonding is still good and the tubes are not cracked.

lucky you, those were particulary prone to failure in some way or another.

A lot of people cry the sky is falling and Al frames are failing. I put up a poll, and got only one real response for a series of frames failing. I asked that person to give me the names of the shops, and they refused.
I called almost all bike shops in San Diego to ask if they have had any Al frames braking, with the exception of Trek shop. None said they had any problems. One shop guy (pref downtown) said "but why would you want Al, it sucks, get a steel frame", so at least I wasn't getting just Al fans.

I have no doubt that steel may be better strength wise than AL. But if no AL frames have failed, or statistically, not that many in comparison, why would you worry?

I have an AL road bike, and it's fine. It is stiff, and light. I find the stiffness fine. I am going to buy an older steel frame and do an honest ride comparison to see which I prefer.

I have a feeling though, this will be the results: Uphill, Al would be better. Straitline, steel may edge out in a comfort basis (easily solved by a carbon fiber seat post, as I've heard). The place where I think steel may help: extreme speed down hills with a lot of rough pavement.

The other day, I was going down the 94 into barret junction, and I was a little nervous at the down hill control at speeds of 45. A little absorbtion of road irregularites would have been preferable.

So far, that's the only weak point to Al that I can think of.

Originally posted by smelly
What if an aluminum bike is crashed? Will it fall apart?

Mine didn't. Twice.:D

Most frames will last as long as the welds do.

I have ridden Cannondales. I am a large rider and like the stiffness. I have put 30,000+ miles on 3 frames. One frame failed because Cannondale stupidly did not extend the rear triangle to the hub but projected a flattened part of the chain stay to the hub and drilled a hole through it to boot. Well it broke at the hub, but by then I had 30,000+ miles on it and Cannondale gave me a new frame of a new style (they did not make mine anymore I guess) so what was the problem?

If you figure that 5,000 miles per year is high mileage that is 6 years of riding. Most people will buy a new bike by that time (at least around here they do). Also in my case, the components start going at that time and rather then get a new gruppo, I get a new bike.

Agreed. I really think it depends on the frame quality and how you ride it. If you ride 10 hours/week, have legs the size of tree trunks, mash your gears (as opposed to spinning), put your bike through hellish road conditions, and expect the bike to hold up for the final sprint of a Cat 5 race, then you may want to look at replacing it every few years.

However, for most of us (including me), wearing down an aluminum frame that quickly seems quite unreasonable. I had an aluminum frame that I put about 3k miles on with no problem. I only got rid of it because I went steel.

Maby I shouldn't, but I'm going to pitch in here.

All this talk of steel vs Al has had me wanting a steel bike. In all honesty, I ride a Trek 2000, 2003 year model that has long seat stays and doesn't seem to ride that rough to me. The only time I realy get beat up in when the roads are realy rough and there are gashes running across the road, every time I cross one of these it feels like a pop instead of a jar, but this isn't often.
I saw a frame hanging up in a store that was one of the high end light steel frames and it looked so much like my Al frame that I thought it was aluminium also, the way the tubes where flattened at the bottem bracket and ovalized in other areas.
I would realy hate to spend more than $1000, just to find out that I liked the Al just as much and it was lighter. I am a big boy, I run between 230-240 most of the time. I also run Bontrager select paired spoke wheels and fortezza tires at the full 140 psi and I still don't think this rig rides that rough.

uciflylow, there are many "steel is real" threads in this forum and for good reason. Many people like steel bikes. I do. One of my arguments for steel is that your average steel frame weighs about 1 1/2 lbs more than an aluminum frame. When you compare that to the weight of the entire bike and your body weight, the weight difference is less than 1%. That sub 1% may mean the world to a racer, but not to me. Of course, there is much more to bikes than just weight, but the pros and cons of aluminum v/s steel go on and on and it's nothing I care to discuss in this thread.

For the sake of the thread topic, I will add that at the last LBS I use to frequent, they often warned me of cracks in aluminum frames, especially around the welds. Many of the riders at the bike shop had been riding for ages. They all either rode steel, and a few rode carbon fiber. Take it for what its worth. Also, one of these guys completely snapped the headtube off of his mountain bike, and it was steel. So it appears that even steel is not invincible.

One problem is that there is not a steel bike for sale with in 100 miles of me in any REAL bike shop! If I had the chance to go spend my money again, I would have liked to have ridden a Lemond 853 frame bike. I have been told that the Trek dealers can't sell Lemond but the Gary Fisher bike shop can sell them but none here cary them. With nothing to compair with, except stores full of Al frames then the MEGGA jump in price to CF. How is a new to road bike riding going to make a distinction?

Try and convince my wife that I neet to spend 12-1800 dollars on a steel frame for this bike when It's less than 1 year old!:eek: I guess I'm stuck with the bike for a few years.

The local bike guru here races on CF but trains on a Waterford lugged frame! NUFF SAID!:(

Uciflylow, Specialized makes a nice Columbous steel bike this year. There has got to be one near you, We were the first Spec. dealer in town and now there are about five other dealers within twenty minutes of us, ah, yes dealer loyalty.
I have steel and alluminum, and have ridden Ti and Composite. Many brands. If I had the money, Giant Composite, best ride I ever had. Every day,in my budget, I like my alloy bike. For long rides I like steel. My least favorite, Ti, When you get them really light, they get whippy, they are exspensive and if you don't take care of where it interfaces with other metals it will punish you by bonding to them.

Ha, Specialized and dealer loyalty go together about as well as Shimano and Campy.

I actually went out today and picked up old Motobecane Mirage bike for $40. It has a steel frame. I made few adjustments and I took it for a ride. It turned out to be nice experience. It glided quite well. I found out that it does feel little different. How should I put this. hmm. Let say there was certain softness to it compare to Al bike.

I'm gonna keep this steel frame as a spare. I think Motobecane makes very good steel frame. I'm impressed with it. I'll keep riding it for next cople of weeks and post my findings.

I've seen a few aluminum frames fail in my day, but not due to the nature of the material. All were bonded aluminum frames and it was the bonds that gave up, not the tubes. I think aluminum frames will last a long time, maybe as long as steel, maybe not. We have a while to wait before we can find that one out.