Steel vs Aluminum

[BeaverTail]

Which metal is better for frame construction, when we consider overall lifespan and durability. When I bought my first mtb 12 years ago Cromoly was all the rage and now it seems Aluminum is more abundant. So what is better? I know aluminum is going to be lighter, but is it as durable and will it last as long.

[Zanetti]

There are no bad materials, just bad design.

[KevinB]

As I understand it, aluminum has no fatigue limit. This means that frames constructed from aluminum will eventually fail. Wikipedia says:

Other structural metals such as aluminium and copper, do not have a distinct limit and will eventually fail even from small stress amplitudes.

(If you don't want to believe Wikipedia, there are other references out there that say the same thing.)

Steel, on the other hand, does have a fatigue limit and will not fail, irrespective of the number of stress cycles that the material is subjected to, so long as the fatigue limit is not exceeded.

What this means is that a properly constructed (and well maintained) steel frame could last indefinitely. All aluminum frames will eventually fail, assuming of course that they are actually ridden.

My own experience bears this out. All aluminum frames that I've owned and have ridden a lot have eventually cracked. I typically get one to two years of use before breakage occurs. The breakage is not due to bad design, but is rather due to simply wearing the frame out.

[spec4life]

No doubt that steel is going to be the stronger more durable frame material...but to say that a steel frame will last forever and an alum frame will fail in 1 to 2 years is a little more than an absurd claim....

The fact is that there are pros and cons to both as with anything else...along with the durability of steel is is more "cushony" as far as dapening vibrations and giving a smoother ride...

Alum on the other hand is very very rigid but is far lighter at the same price range...sure you can get light steel but its not cheap...and if you use it for its intended use it will last far longer than most of the componets on the frame anyway...

There is a reason that most all bikes are alum now....the two foremost are price and weight...

[KevinB]

but to say that a steel frame will last forever and an alum frame will fail in 1 to 2 years is a little more than an absurd claim....

I've broken 5 frames in 7 years. All were aluminum frames. I weigh a bit over 200lbs and I ride 3500-4000 miles per year.

[BeaverTail]

So it seems at least to me that manufactures have moved to Aluminum while not decreasing price and in fact possibly have raised prices and now steel which used to be the cheap stuff is now more expensive.

[spec4life]

I've broken 5 frames in 7 years. All were aluminum frames. I weigh a bit over 200lbs and I ride 3500-4000 miles per year.

Well your putting about 3-4 years of an average riders miles on your bikes in a year then id say which decreases the bikes lifespan....non the less if your snapping that many frames you must be using cheap stuff or using the bike for a purpose it was not intended...if your a big boy get a big boys bike....

[CRed]

I've broken 5 frames in 7 years. All were aluminum frames. I weigh a bit over 200lbs and I ride 3500-4000 miles per year.

Then you're one unlucky SOB,I don't think that's the norm,is it?

[spec4life]

So it seems at least to me that manufactures have moved to Aluminum while not decreasing price and in fact possibly have raised prices and now steel which used to be the cheap stuff is now more expensive.

well low end cheap stuff like walmart bikes are still steel...however now most all "real" mtb manf. have moved to alum...however there is still a niche market for steel frames so there are specialty makers make some high quality steel frames but because it is a small market they are expensive....

[CRed]

So it seems at least to me that manufactures have moved to Aluminum while not decreasing price and in fact possibly have raised prices and now steel which used to be the cheap stuff is now more expensive.

Not too many of the big guys are making frames in steel anymore,but there are a lot of boutique shops working in steel which is why it might seem like that steel is so much more expensive then aluminum.

Jamis does some steel and they are excellent values,I have a Team Draon 06 frame and it's very nice.I was going to build it up,but got a great deal on a Ventana and couldn't pass it up.I also have the Jamis Dakota XC frame which is also very nice,but it's 631 instead of 831 like the Dragon.

I'll get around to selling them soon hopefully.I need new wheels!

[KevinB]

non the less if your snapping that many frames you must be using cheap stuff or using the bike for a purpose it was not intended...if your a big boy get a big boys bike....

Three of the broken frames were 2002-2003 Specialized Enduro frames. They upgraded me to an S-Works frame at one point. It was a sweet frame, but I think I only got about 18 months out of it. The most recent Enduro frame, a 2004 model, has held up fine, but (I assume) only because I've stopped riding it. My son rides it now. (I decided I should have a backup bike, so I bought a 2004 Iron Horse Hollowpoint w/ DW-Link suspension. Not many folks knew about DW-Link back then. I was blown away with how efficiently it pedaled. When I got my Enduro back from the shop, it was relegated to the backup role.)

I do put in quite a few miles, but I don't do anything too wild. No big drops or anything like that... I would definitely say that I'm using the frames for their intended purpose, or perhaps even below their intended purpose.

[spec4life]

Three of the broken frames were 2002-2003 Specialized Enduro frames. They upgraded me to an S-Works frame at one point. It was a sweet frame, but I think I only got about 18 months out of it. The most recent Enduro frame, a 2004 model, has held up fine, but (I assume) only because I've stopped riding it. (My son rides it now.)

I do put in quite a few miles, but I don't do anything too wild. No big drops or anything like that... I would definitely say that I'm using the frames for their intended purpose, or perhaps even below their intended purpose.

well... ...quality frames that should be able to take a beating...maybe your just the unluckiest mtber iv ever seen....

[trailville]

15 years ago, aluminum frames were generally more expensive, but in recent years the bike companies figured how to manufacture aluminum frames very inexpensively (you can get aluminum hardtail frames for under $100 retail). Also, in the old days of rigid bikes, ride quality was affected more by frame material and construction, and steel is generally more forgiving (not as harsh a ride as aluminum). Today, suspension plays a far more important role in ride quality, so the harshness of an aluminum frame is not as big an issue (especially in full suspension). So since the bike manufacturers can make frames lighter and inexpensively using aluminum, we end up with a lot of aluminum frames.
There is still a market for steel hardtails so there are still some manufacturers producing them. I built up a steel On One Inbred 456 hardtail a couple of years ago, and also have a steel rigid singlespeed. The DJ/Urban crowd also love steel (as to the BMXers) so you'll see a lot of steel frame offerings for those types of bikes.
As to durability of aluminum, I'm still riding an aluminum hardtail I purchased in 1994. It's been ridden hard over the years (though it's on towny duty right now) and still holding up. This was a rather burly aluminum frame to begin with (94 GT Pantera AL) so I'm sure that has something to do with it. If you go for the ultra lightweight stuff, it's going to be more apt to fail regardless of what it is made of.

[regnier]

Scandium is the way to go. Stronger than aluminum and lighter! Could it get any better than that?

[civil]

Scandium is the way to go. Stronger than aluminum and lighter! Could it get any better than that?

Scandium frames are just aluminum frames with a higher scandium % in the alloy (around 0.5 % IIRC). More of an "improved" aluminum frame, depending on what you consider an improvement.

[herbn]

i have a klien rascal that is just used very rarely these days, but it was my main bike for at least 5 years,i've never been over 175 or so, and generally under 170. i think when you go up just another few pounds ,maybe 190+ stresses seem to really kick in geometricly,every bump into a rock ,step drop, even pedaling stresses getting that weight moving, seem to take their toll on cassettes and freewheel pawls. There are alot of really old cannondales out there,not really in the woods but you see alot of people just cruis'n around on them.Those people that always pull out that stress limit thing do fail to mention exactly how long it will take for an aluminum frame to fail "just riding along" on the road i see a vitus bike on many saturday rides,gotta be from the 70's when should i plan on seeing it shatter on a pothole or rail crossing.

[kapusta]

Which metal is better for frame construction, when we consider overall lifespan and durability. When I bought my first mtb 12 years ago Cromoly was all the rage and now it seems Aluminum is more abundant. So what is better? I know aluminum is going to be lighter, but is it as durable and will it last as long.

Hardtail: I'll definitely take good steel over aluminum. Steel frames have all felt better to me.

FS: I'll go aluminum. Suspension takes care of the smoothness of the ride, I was less flex.

[AirDefense]

Aluminum rides stiff. Steel is less stiff and more forgiving. Try Lemond for steel road stuff.