TreyWestgate

so I heard that as an aluminum frame ages it gets more rigid and stiff?. As if it wasn't stiff enough to start with.

That this also continues until it is so rigid and stiff that it just pops like that.

and I also heard that corrosion is also basically a death sentence and is like cancer for the frame.

but I heard that unless it has progressed to the point of being pitted that there is nothing to worry about.

my one bike has some light patches of corrosion and I wondered of it is worth trying to do anything with it or is it really going to last much longer.

Like can I sand it off and put some kind of oil or sealant on it?.

But the real questions are, does an aluminum frame fail hazardously when it does, pops in half and eats pavement?. and does corrosion even a litle mean a significantly shorter life?.

it's been good for maybe 7 years now, but might be 8 or 9 years old.

don't want that to be the last bike I ride in this way.

Almost every bike is aluminum now.

But do they really last?.

or is it just a way that someone makes more money because you will have to buy a new bike more often?.

steel is almost not existent.

SkyDog75

No.

There are two different processes you're sort of referring to:

Work Hardenening: When metals are subjected to flex cycles that exceed their fatigue limit, they may become harder and more brittle, making them more prone to breakage or cracking.

Fatigue Limit (quoted from Wikipedia): the amplitude (or range) of cyclic stress that can be applied to the material without causing fatigue failure. Ferrous alloys and titanium alloys 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 aluminum 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 107) is chosen to represent the fatigue life of the material.

Engineers who design machines made from aluminum -- whether they be bicycles, airplanes, or whatever -- are aware of the material's properties. Their designs should be built to withstand the cyclic stresses they'd be subjected to within a reasonable lifetime.

Corrosion is an irreversible process, and it can be the death of a frame if it progresses far enough. That's true whether the frame's steel or aluminum, as both can corrode. Take basic precautions, like making sure paint prevents bare metal from being exposed to the elements, and that'll help keep corrosion in check. If corrosion has started, clean it off and then seal it via touch-up paint or some other means.

In my experience, when a steel or aluminum frame fails, it'll crack somewhere, but not generally catastrophically.

A quality aluminum frame that's been treated well will generally last a long, long time.

Steel frames occasionally fail, too. You can find plenty of examples of cracked steel frames if you search.

TreyWestgate

Steel also seems to be plain outdated in the modern bike world.

People have made aluminum and carbon into the big thing.

I bet I will not find a steel bike at any of the bike stores for a 100 mile radius or more.

All the bikes in every store are aluminum and there might be one or two carbon bikes.

and when and if i should find a steel bike, there are actually many aluminum bikes that still cost less than the few steel bikes that are made.

tcarl

You may or may not "find a steel bike at any of the bike stores for a 100 mile radius or more", but if you want one there are still multitudes of fine steel frames/bicycles being made.

Maelochs

Any metal bicycle frame will last longer than you want it to unless you completely abuse it or it was horribly welded. Titanium is hard to weld well, so more Ti frames seem to crack, proportionately. Steel and aluminum, and well-made titanium, are lifetime frame materials ... you will be able to pass the bikes on to your kids if you do basic maintenance.

Eddie72

Aluminium is an excellent material for building bike frames, it's light, strong, inexpensive and resistant to corrosion. If you do get some surface corrosion, it's worth touching up cosmetically but it's unlikely to cause any structural problems. How long a frame will last is dependent on both the material and the way it's designed. To make an aluminium frame light and with some flex for comfort, designers will typically think about how long they expect it to last. This could be one season for a super light racing frame or a couple of decades for a commuting bike. I've broken two aluminium frames over the years through normal riding, both failed safely in that the first I was aware that I'd cracked the frame was a creaking noise, so no sudden breakages. As to the nature of an aluminium frame changing over it's lifetime I think it's still an open question, with frame designers still disagreeing on that one.

An issue in all of this (for me at least) is how you feel about riding a particular frame. When I ride an aluminium frame I'm aware that it's built with a material that's designed with a particular lifetime (which could be many years). When I ride a traditional steel frame I like the fact that it could go on for ever.

Chuck Naill

Manufacturers of higher end bikes have a life time guarantees on the frame regardless of the material, right?

wschruba

Yes, but: from people who actually deal with this sort of thing, it is generally held to mean the lifetime of the product, for the owner, not the lifetime of the owner. This leaves room for ultra-light designs/designs intended for heavy use, all under the same warranty.

That said, most manufacturers will replace it anyway, and chalk the expenses up to retaining a customer. The vast majority of manufacturers will not warrant components that have been raced, though, citing much rougher usage (life, you might say).

shelbyfv

You probably have other cycling related issues more pressing than the life of your frame.

Retro Grouch 

That's been my experience.

Retro Grouch 

Yeah, but it's the lifetime of the company that's guaranteeing the frame.

steve0257

One of my bikes has a lifetime frame guarantee, but somehow I don't expect much luck if I ever have to replace the frame on a 45 year old Schwinn.

cyccommute 

Some of what you've posted is correct...and more correct than TreyWestgate posted...but you are also wrong several points.

While it is true that both metals can corrode...i.e. oxidize..., the mechanism for oxidation is very different in the two materials. When steel is exposed to oxygen, it forms the oxide (rust) continuously. Aluminum forms an oxide layer on the outside of the metal that is almost impervious to further oxygen infiltration and protects the underlying metal.

Chlorides from salt are damaging to both metals through the formation of either iron or aluminum chlorides on the respective metals. The difference is that aluminum strongly bonds to the chloride and goes, essentially, no where. Iron forms a chloride salt as well but the chloride ion is replace rapidly with oxygen which releases the chloride to pluck out more iron atoms. The process is catalytic so any chloride that is available will continue to eat away at the metal. This works in a moist environment and most chlorides that we use on the road will absorb enough moisture out of the air to keep the process going.

I don't know how much experience that you have with frame failure but I've broken 4 frames...two of each material...along with a number of components made of either material. Aluminum, as you said, cracks and even tears. It makes a lot of noise while doing so. The frame or part will creak and groan a whole lot before failure. Failure of aluminum is generally a slow process.

Steel, on the other hand, tends to shear off rapidly with little to no warning. Axles, pedal spindles, spokes and even frames have all gone "ping" and are broken. No warning, no bending, no creaks or groans. When hub axles have broken, I didn't even know the axle was broken until I happened to take the wheel out to fix a flat or perform some other maintenance.

Both very true.

Kindaslow

I would prefer to ride a bike so much that it wore out, broke, and I hung it on the wall. However, the longest I have kept a bike is about three years. However, I have broken metal parts in under three years. MTBing can be hard on parts!

cyccommute 

There is a whole lot to unpack here.

In a word, no. At least not that you'd notice. I have, and have had, aluminum frames that are 8 to 11 years old that are still going strong and show no signs of frame problems.

Steel, yes. Aluminum, no. See my post above. Aluminum passivates...a fancy word for stops corroding... quickly while steel does not.

If you are talking about aluminum, you shouldn't have anything to worry about. You may be seeing chloride corrosion but simply brushing off the white deposits should be sufficient. If you feel the need to sand it and, perhaps, paint it, just sand lightly. You don't need to remove much material at all.

If you are talking about steel then, yes, you have to be more aggressive and you need to coat the steel to prevent further corrosion.

Any "new" material that is introduced...new as in not steel...will be said to "explode" when it fails and will usually result in the death of the rider and all the people within a 2 mile radius. Fiberglass Corvettes were said to just "shatter"...they didn't and don't. Aluminum bicycle will fail "without warning!!!!!!" and leave the rider just a grease stain on the pavement. There are, literally, millions of aluminum bicycles out there that aren't death machines. Carbon fiber is said to "shatter" just like fiberglass...a golden old

I've tracked bicycle mileage since 1988. I have an 11 year old Salsa Las Cruces that have more than 17,000 miles on it and it is going strong. I had a Cannondale T800 with 10,000 miles of touring on it that was only retired because I found a different colored frame...I will keep it in reserve for future use...but it is still a good frame. I had an Specialized Stumpjumper Pro that was 13 years old with 5000 very hard mountain bike miles on it without issues.

On the other hand, I've had 2 steel frames that are supposedly indestructible...both mountain bikes that were ridden off-road...that failed after about 3000 miles. One of the aluminum frames that failed on me had about 7000 mountain bike miles on it but it was another Specialized Stumpjumper Pro with a M2 frame which is a material what was prone to cracking. That's a materials problem, however.

Well, yes as my experience shows.

The technology changes of the components drives people to buy new bikes more than concerns about longevity of the frame material does. Changes in frame material also drives people to buy new bikes. Steel was replaced by aluminum because it is lighter. Aluminum was replaced by carbon because it's lighter. Back in the day, a 25 lb steel bike was considered "light". Then a 20 lb aluminum bike was considered "light". Both are extremely heavy compared to 14.99 lb weight of carbon bikes which could be even lower if the UCI weren't such stinkers.

See above.

SkyDog75

Thanks for the counterpoint. I certainly wasn't "Billy Madison wrong", but you've added helpful detail and nuance. ;-)

fietsbob

My Fancy Pro level AlAn developed Cracks in the 'lugs' .... theyre actually screwed together and epoxy bonded.


Aluminum frames became stiffer to last longer , since it is the flexing metal fatigue, that can become a problem.




...

NormanF

An alloy frame will last a lifetime taken care of.

Heck, aluminum airplane bodies and wings have lasted well beyond their projected lifespan.

And bicycles receive far less wear and tear than airplanes. Wouldn't worry about it.

ClydeTim

I had 2 aluminum frames pop on me! One on a steep 12% climb. I felt it pop and thought I broke my crank. Funny feeling swaying side to side. Popped at the BB area. large break, almost split the downtube in half. Glad I was going up and not down. Though it more than likely would not have popped on a downhill.

Second one popped at the chainstay near the rear axle. Was the day after a tough climb. It popped about 5 miles into my ride. I could not pedal the bike without a great deal of play. I tried to push myself home gently like a scooter but after 3 miles, it felt very unsafe to me. I called for a ride.

I've heard aluminum was great for big guys, I don't believe that any longer. Both frames popped after 13,000 miles and about 3 years.

Maelochs

I am a big guy and my 1983 Cannondale is ... well, do the math. My Dawes has already survived a cross-country trip and a couple years as my main ride locally.

I wouldn't try to change anyone's mind ... never seen that happen anyway ... but as for myself, weighing in over or around an eighth of a ton and doing most of my riding on aluminum, I feel pretty confident.

There have been posters here talking about breaking a frame a season, steel, CF, Al .... so maybe I am stupid to load my Cannondale with several dozen pounds of stuff and heading out on the road ... but I am stupid enough to enjoy it so ....

Smut peddler 

I know this thread is dead but wanted to chime in. I completely agree with big man. Im 250lbs. i own 3 second hand cannondales an 86' model that i use on the trails, 93' model that i use on the roads and 96' model that i ride wet over rocks up and down curbs i even bunny hop on it also Ive owned all for over 8 years I live in a hilly area and love smashing up those hills for tough workouts. Now it could be that im more comfortable on them and they've become like an extension of my own body so im not even thinking about the abuse im putting them through. But with all that said i think them all being over 20-30yrs old having at least two owners me being 250lbs and getting some heavy unorthodox use (for a road bike) on them i give a great shout out to aluminum. Funny thing i do own steel bikes too and i treat them like theyre made of Styrofoam i know theyre strong as hell but thats out of pure love for those frames theyre my babies i dont wanna even get a scratch on them. Guess you can say i dont respect aluminum and view them as my disposable bikes??

CliffordK

I know of a bike store about 20 miles from home that doesn't have any carbon, aluminum or titanium bikes. EVERY one of their bikes will be chromoly STEEL. I suppose they'll talk to any customer that comes in the door no matter what they ride, but I think they only tune up STEEL customer bikes. They sell parts primarily for STEEL bikes. Probably take in STEEL trade-ins too. And, they even encourage their employees to ride STEEL.

A couple of years ago, I was thinking steel was a bit passé, and perhaps it is. However, there are good reasons we still see steel around. It is probably the easiest material for a small manufacturer to work with. It is a solid metal, and reasonably durable (also good for a small manufacturing company). The alloys have improved over the decades, so butted chromoly is more common, or at least thin wall chromoly, and the new alloys are easier to weld than the old.

Perhaps the reasons we see so much aluminum is that so many of the vintage steel bikes were HEAVY. Not that they needed to weigh 40 pounds, but the cheap bikes were made heavy. So, as welded aluminum became more common, people moved away from the steel. Rust???

With modern manufacturing, people have been optimizing shapes for carbon and aluminum bikes, while the steel bikes basically have the same round tubes they've been using for the last century, at least on the outside. But the manufacturing tech has improved.

Smut peddler 

People a lot like myself respect the steel. Steel owners and riders are the true purists of bicycle frames. Whenever im in the market for a new bike to add to the collection its steel (aside from a nice looking vintage cdale) and im always like i need a steel bike i can ride daily and commute on and put alot of miles on and feel confident in knowing its gonna be okay and can take it and can be repaired when and if it fails but everytime i get it home im like i cant its too dreamy i need to preserve it and only take it out when i want to show my steel off. Btw my 3 steel bikes are lighter than my 3 cdales. Also have an interesting miyata (designed for gravel) which consists of an aluminum main triangle bonded to steel stays and a steel fork which is pretty damn heavy but super fun to ride plus the fork and stays absord and mute any bumbs or rough terrain before it reaches the main triangle and rattles me. Real cool bike. Then an old swiss sporting good stores house model made from Columbus aelle felt super heavy when i bought the frameset then was expecting a tank when i built it up surprisingly it was almost feather like comparef to what i imagined the end result would be.

So ive come to find value, desire, silver linings in both materials ive rode. Depending on the purpose of your bike i think thats just the way it pans out. For me personally there is no definitive steel or aluminum only. Which may be why people swap out their forks to other materials or why manufacturers build frames from two materials. Or lighter components to drop overall weight. Blah blah you know just preferences.

Doug5150

Steel and aluminum frames both can suffer fatigue failure.

Aluminum corrosion is white dust so it's not as noticeable as the brown stuff you see on steel. Salt (from the road, or from your sweat landing on the top tube) can easily corrode aluminum over time.

Fatigue failure is very difficult to predict in advance; the generally-accepted way to measure it is to conduct tests on multiple samples and do destructive analysis on them, and then average the results. So it is only ever an estimate.

Racing bicycles tend to fail sooner since they're made thinner to be less weight, and that sacrifices their usable lifetimes.

Bicycle companies went to using aluminum because it was cheaper than using lugged steel or welded steel.

Most custom frame shops still use lugged steel since it is the easiest way (and the cheapest, on a small-shop scale) to produce a high-strength frame that was relatively easy to repair if a frame tube got damaged.

(...Fillet-brazing steel is a popular technique among home frame-builders but do any 'real' frame companies use it?...)

Lugged-and-brazed steel frames are generally held to be the easiest to repair, especially in non-bicycle-shop situations. A brazed-steel frame can be brazed some more in the field with any oxy-acetylene torch and brass rod, anywhere in the world.

If you get a general-use frame (such as for touring), deal with corrosion as it appears and ride it reasonably gently, it may very well last your whole life. And if it doesn't, it's just a chunk of metal anyways. It's not the ark of the covenant. -Which was supposed to be made of gold, that is almost twice as heavy as lead, and so probably weighed a metric butt-load of pounds (they showed two guys carrying it in that Indiana Jones movie, but that was Hollywood dreaming. A cubic foot of gold weighs 1200 f***ing pounds. It would have taken at least four 'normal' guys to carry it at all)

corrado33

Really, really bad comparison. Aluminum airplane bodies are inspected before every flight and have a very, very set life cycle. Boeing builds planes to be flown for X number of flights before they discontinue the plane.

Also... failure on a plane means death. Failure on a bicycle means a bit of injury, if that. So again, very bad comparison. Completely different set of circumstances.