most bikes use commercial-grade carbon fiber cloth that is intended for things like sporting goods and automotive aftermarket applications.
There is a seperate aerospace grade of carbon fiber for those applications.

The only one I know of that is different is Fondriest, who advertise the use of F1 carbon fiber- of much higher quality than the normal sporting goods grade cloth. I don't know if this is aerospace or not but that is the only one that differs from the majority of CF bikes that I know of.

there are a few steel mountain bikes out there, but the main reason is cost. It is expensive to build a lightweight steel frame, and if people are going to spend a lot of money, most people would rather just get a full suspension (FS) bike. Steel is generally not used for FS bikes becuase you do not need the "magical ride" of steel in a full suspension - you have the suspension to absorb shock, and in a full suspension design, flex is very bad because it means that all the moving parts get worn faster. wow. that was quite a run-on wasn't it?

anyway, back to the original topic, there was a cat 2 racer on this forum a while ago who went by the name Maruzio or something like that. I distictly remember him talking about breaking his frames a lot in the chainstays right behind the BB...

You're probably right although I do know that Aegis uses aerospace grade carbon fibre.

Bianchi and Specialized make several mass market steel bikes. Many (most?) of the Italian racing bike makers (Serotta et al) also make a few steel frames and then there's the whole custom market...

I'm looking at Ritchey and Co-Motion for steel frames. I understand Jamis makes a steel roadbike too don't they?

First of all cheap steel can be robotically welded-true! But we were not talking about Wallyworld class of bikes.

Second, airliner manufactures stress test their aircraft then tell the airlines companies to keep the air speed not higher than 525 mph or whatever that craft was design for. Ever notice the max speed rating on aircraft? That is not the max speed the engine(s) can push the craft, that is the max rated safe speed for the airframe. They do this because the AL frames will flex too much and result in failure and or the extended use at higher speeds will shorten the life expectancy of the aircraft. Even at that when flown at recommended air speed they are then retired at what ever age the manufacture recommends because of the accumulated effects of stress on the frame could lead to failure and that is usually around 20 years for larger airlines. Plus steel would be too heavy for an aircraft to fly so AL or CF is the only real product to use. Some light weight aircraft such as ultralights and microlights use cromoly for their frames because the lightweightness of the fabric skins on the wings combined with people trying to get the most out of their engines performance and attempting aerobatics have led to a high percentage of AL frames collapsing whereas the cromoly steel frame did not-as often. But in these instances we have a case of pilot stupidity taking the airframes past their intended safe margins.

Then ask yourself why don't they make skyscrapers, or bridges, or springs in cars and trucks-big or small out of AL instead of steel if AL is so great. AL is not bad stuff used within it's design limits and on bikes can be great for lightweight crotch rocket, but AL will not last as long as steel or TI (CF is still questionable); when the last 15 years of AL bikes have been around for another 20 years then we will have more answers.

In LBS's your right, you will have a hard time finding good lugged steel bikes because most good steel bikes are hand made by the finest frame builders in the world and due to that the cost becomes higher than what the average person will spend for a bike. But there are plenty of steel welded (no lugs) frames in LBS's you may have to ask. But brazed lug or bonded lug (very rare to find now) construction is still the strongest (howbeit heaviest) way to attach tube to make a frame.

Cervelo Prodigy,Fuji Roubaix Pro,KHS 800, Masi. The Jamis and the KHS are very nice.

The only structural part of an aircraft still made from steel is the landing gear. The toughest material ever formed into tubing is airmet100, heat-treated steel, designed for carrier-landings. This steel has been formed into bike frames, but it was a passing fad.
The old standby, Reynolds 531 was originally designed for aircraft in the 1930s, to be used a internal bracing.

I almost always keep my speed below 525mph.

almost?

Hmmm... that'd be a neat feature for bike computers: a way to set various indicators for V-speeds (Vne, Vno, Vs, etc...). Then again, I'm not sure what my Vne would be but I'm pretty sure I wouldn't be staring at my computer's display if I were anywhere near it. Perhaps, an audio cue might work?

Ah ha, now you know why I ride a steel bike so I can go above that speed!

Aluminium does have a fatigue life but in most cases if your not a pro racer or a tourer doing tens of thousands of kilometers a year your not liable to wear out the frame before every thing else is knackered but .............
if you use an a-frame type cycle trainer a lot you can clap out an ali frame in a very short time because your subjecting it to loads it was not designed to withstand and the more hours a session and the more force you apply then the faster it´ll happen .
As a general rule the lighter a component then the shorter it´s working life and this holds true of frames as well ( mind you I´ve seen ex-racing frames from ONCE being sold on and lasting for years after so .............. ) ( ONCE used Giant frames which tended to be amongst the lighter frames in the peloton )

I did not know about the A frame trainer thing. My LBS said when I bought my Cyclops Fluid that it would not do what you mentioned, BUT I had heard from other places that what you said is correct-so I guess the debate continues. But my thought process is that if what your saying is correct then that would still apply on the street just not as rapid of a pace.

Your right about the weight issue to; that applies to anything even autos. A lot of drag racing folks use AL parts to reduce rotational weight thus faster rpm spinups but they sacrifice engine life in doing so-but most of them don't care about that they just want to win. Problem is you get this thought process filtering down to street cars except the engine life subject is glaringly missing or hyped away to sell parts. VeloNews also reported the same thing about light weight stuff in their Buyers Guide dated 2003.

See: https://www.nordicgroup.us/bikerec/images/aloha243.jpg

From: https://www.nordicgroup.us/bikerec/

"Invariably, when the aluminum versus steel debate pops up, someone chimes in with an analogy about airplanes. They ask why we're not worried about aluminum airplanes falling out of the sky, but we're worried about aluminum bicycle frames breaking. I'm convinced that buried somewhere in the sales training from Trek, Cannondale, and/or Specialized, there is an FAQ that tells salespeople to use the airplane analogy to address concerns from customers about aluminum framed bicycles.

Like most analogies, it's a poor one. The fact is that we are worried about airplanes falling out of the sky. Recall the 1988 incident in Hawaii where an Aloha Airlines Boeing 737 suffered a structural failure. This was an inter-island plane, which had an abnormally high number of compression/decompression cycles, which fatigued the aluminum skin, causing stress cracks that propagated from rivet locations. Amazingly, only one person was killed (a flight attendant who was sucked out during the decompression). Of course the solution here was not to make airplanes out of steel, it was to increase inspections, and limit the number of stress cycles before an aircraft is taken out of service."

The point was not that aluminum does not fatigue. Aluminum certainly does fatigue. The point was that the properties of aluminum are well known and given a known stress environment, we can design structural components from aluminum that will give predictable performance. The fact that we use aluminum for aircraft is proof that aluminum can be safely used with little fear of an unexpected disaster. The analogy is not a poor analogy.

The art of engineering is to design an item that can perform to a given specification and be constructed for a reasonable cost. There is no questoin that a quality bicycle can be built from aluminum. It can be built from steel, carbon fiber, or titanium as well. Some people seem to believe that just because a given piece of steel has a fatigue limit, all steel bicycles are designed within that limit. There also seems to be a beief that all aluminum frame bicycles are designed to have such short fatigue lives that you are taking your life in your hands just to go around the block. I suspect that neither of these beliefs is true.

For all of the aluminum bikes sold, you'd think there would be a constant complaint on these boards of people who have had their bikes suffer a fatigue failure. I certainly don't read that here. Over on mtbreview you can see all kinds of pictures of failed frames, but these appear to be predominately overstress failures at welds and are almost certainly manufacturing errors or simple abuse failures. On the other hand, in the book, 'A Bike Ride', Anne Mustoe rode her steel bike around the world. When she got about 4/5ths the way around, her steel bike developed a crack in one of the tubes. Whether this was fatigue or material defect is unknown (does it matter?) but the point is that her frame certainly did not go forever without a failure.

Nonetheless, a bike does not need to last forever to be a quality bike. If an aluminum Trek 'only' lasts 10 years, but costs 1/3 the price of a comparable Rivendell that may last a lifetime (or may not) the Trek may be a better buy since few people would need to buy more than 2 replacements anyway before they stop riding. Chances are you would be tired of the old Riv after 30 years anyway. Besides, Trek warrantees the frame for life anyway, so as long as you don't plunge down a cliff when the frame cracks, you shouldn't worry too much about the frame.

By the way, it's known as "endurance limit" not fatigue limit.

Dave

My bikes are all steel but I'm always doing searches on how long things last. Cars, bikes, guns, power tools ....

I found a guy who owns a Trek 1420 circa 1991/2 . They have aluminum frames and it's owner puts on 14K/year. His bike had 140K miles on it before he replaced it. My guess is that he or his LBS stripped all the threads from several rebuilding sessions.

I've never met anyone in person that spent that much time on a bike but I guess they are out there. He looked like a 25 year old with grey hair and a grey beard. He was probably in his mid 50's.

Probably Cannondale... my friend dented his new R2000 the first day he had it when his heel knicked the top tube getting on. Unbelievable... I mean yeah, its light, but if you so much as look at it crosseyed it will fold in half.

I have a dent in my mtb's toptube- if Alu, I'd toss the frame in the trash.
Being steel-not a worry @ all.

about 25 years ago i was really into TT especially 10 miles, for this I brought a custom built frame from a company called Argos in the UK. CrMo tubing was the new thing at the time and a company called ishiwata provided the double butted tubing for the frame. the long and short of this was I had the frame made and I was dissapointed in that it wasnt as light as I had expected it to be. even the toe clips would overlap the front wheel and there was hardly any clearance. The bike felt very dead and one day I noticed that there was a dent in the top tube. I was so cheesed off with the frame i decided to sell it off and i brought this aluminium frame called an ALAN which was a italian frame with aluminium lugs. the bike rode beautifully it was light weight and it was used regularly. I have fallen off the bike a few occations and i have lent it to a friend who is one hell of a sprinter. in fact he exherted so much force on the pedals that he busted the rear hub spindle on the wheel. I still have the bike to this day its in fantastic condition being completely anodised it has not coroded at all
Strange to think that aluminium back in the early eighties was an exotic material. My ALAN back then cost me an arm and a leg

"All the macho mountain bikers who brag about never washing their bikes are just being foolhardy."

Not to mention, they have dirty bikes. I for one cannot stand to ride a dirty bike. Just part of my genetic makeup I guess?

As for frame failures, I 've never had a failure on anything? Guess I'm not crazy as the next guy, lol. I did have a friend who snapped a Chromoly Hutch frame back in the 80's. Of course he weighed a good 180 lbs, and was trying to jump a concrete culvert about 5 foot deep(with no ramp I might add). He hit the edge of the other side with the middle of the downtube, and blammo. snapped both the upper tube and downtube clean in two. He lived, surprisingly enough.,,,,BD

Jamis recommends replacing an aluminum framed Taxi every 10 years due to fatigue.
Steel framed Boss models should be replaced every 3 years.

ALAN(all caps mind you) frames where the coolest frames, absolutely, bar none, end of story. The Record model was the coolest.