General Cycling Discussion - frame materials

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View Full Version : frame materials


CliffNY
11-02-08, 08:06 AM
I have always found aluminum to be light, rigid, transmits a lot of road vibration. Steel (12 speed Kabuki) frames seem to be less rigid, transmit less road vibration. Carbon (LeMond Versailles) to be rigid but absorbs vibration, has a "feel" somewhere between aluminum and steel. I know there are many posts re: Titanium but I would like for someone with experience to compare Ti to the above. If the above observations do not seem correct, I invite comment/observations. If someone can relate specific advantageous ride characteristics of each frame material to road, cyclocross, MTB and touring that would be great.


Retro Grouch
11-02-08, 09:17 AM
You should probably be posting this in "Religion and Politics". Really.

People have a lot of strongly held opinions on the topic. Many of them conflict. Objective data, if any exists, is hard to find.

Rogue Leader
11-02-08, 09:28 AM
You should probably be posting this in "Religion and Politics". Really.

People have a lot of strongly held opinions on the topic. Many of them conflict. Objective data, if any exists, is hard to find.

I agree

:trainwreck:


stapfam
11-02-08, 12:40 PM
Too many options on the various bikes.

For road use- most would now prefer C.F. and it is getting cheaper- but those of us with "Quality" Aluminium find that there is no problem on the ride quality either.

Cyclocross and it seems to be either Alumium or steel for the life of the material.

MTB and Although C.F. is appearing- it is expensive and not commonly used. Aluminium seems to be the favoured material- especially as Suspension is the norm on these.

Touring and steel rules. Gives a very compliant ride and has a long life. On top of that- you can always get it repaired in the remotest parts of the world if you are unfortuanate to have it break on you.

But then you will always find followers of all the materials across all the disciplines of cycling. Ti is not as popular as it used to be since C.F. became more readily available- but You also have to be conversant with all the different grades of all the materials in all the disciplines aswell.

CliffNY
11-02-08, 03:00 PM
Thx to everyone who replied. The observation "not much objective data exists" intrigues me, surely there are some engineering types who could give insight to these materials from the standpoint of flex vs stiffness, etc. One question in particular, I have always been told steel is 3 times as strong as aluminum but 3 times as heavy - so where is the benefit?

xenologer
11-02-08, 06:37 PM
One question in particular, I have always been told steel is 3 times as strong as aluminum but 3 times as heavy - so where is the benefit?

It's 3 times as strong so you only have to use 1/3 as much of it for similar strength, hence that weight issue suddenly doesn't look so bad does it?

Garfield Cat
11-03-08, 09:12 AM
Even if you had the "engineering type" paper with lots of technical data on stiffness and compliance, you might still be into "data overload". Those white papers need to be applied towards the 4 different riding disciplines that you first mentioned.

Even if applied, it needs to be applied towards the specific manufacturing prodiucts out there in the marketplace. Is the top of the line time trial bike about the same for all manufacturers?

That's the "objective" thing that will be difficult. I don't think you will find it.

cachehiker
11-03-08, 09:20 AM
so where is the benefit?

It's not exactly 3 and 1/3 so a similarly stiff steel frame will always be heavier. The benefit comes from steel's excellent high cycle fatigue limit. Aluminum sucks for high cycle fatigue. You can therefore build frames closer to their ultimate strength and/or low cycle fatigue limits without worrying as much about durability. This is where the smoother ride comes from.

Steel also hits its yield limit long before it hits its ultimate strength so it will often bend before it breaks. It is therefore less prone to catastrophic failure. You see the problem, you quit riding, you get it fixed, and you continue with your tour.

When it comes to aluminum there is no such thing as light, durable, smooth, and cheap. You usually have to sacrifice one of them. Steel will generally be durable and smooth but either heavy and inexpensive or not so bad and fairly expensive.

bbattle
11-03-08, 12:16 PM
Thx to everyone who replied. The observation "not much objective data exists" intrigues me, surely there are some engineering types who could give insight to these materials from the standpoint of flex vs stiffness, etc. One question in particular, I have always been told steel is 3 times as strong as aluminum but 3 times as heavy - so where is the benefit?


Ride quality is subjective. Engineers can bury you under a ton of data but in the end(pun intended) it comes down to what you prefer. Years ago, a study was done comparing the ride qualities of various steel tubesets. The author was a bit dismayed he couldn't tell one from another. Others in the study found only subtle differences. The final winner was Columbus Aelle; a big surprise.

Your wheelset will play the biggest role in ride quality with tires being the most important component.

Frame geometry is another big factor. Changing the headtube angle half a degree will change the ride; so will changing the seat tube angle.

http://www.torelli.com/tech/material.shtml one person's opinions on the subject.

Garfield Cat
11-03-08, 02:32 PM
Even if Cliff NY goes to the other post, the Frame builders, he will find out that those tubes, whether aluminum or steel, come in all different shapes and then geometries.

Someone who wants to know which is "best" will be hard pressed. Maybe that's how NASA spends all that money, billions, to figure things out. NASA must have a ton of engineers going through their materials science to determine what's best for a launch and re-entry.