General Cycling Discussion - Frame material - 853 or chromoly?

Any comments on either of these two bikes being offered by Thorn?
Can 853 take the knocks?
http://www.sjscycles.com/thornbrochure.asp

853 is the best steel frame on the market for tensil strength, it approaches the breaking strength of TI. See: http://www.fortunecity.com/olympia/piper/18/general/tube_technology_2.htm

Yes that is what I had gathered but Thorn - who are are extremely experienced in this business seem to suggest that it maybe a little too delicate for rough use.

the 853 has strength of 1350Mpa, that's higher than 725's yield..

So i guess the air hardened steel has superior strength at the same density(weight).

Note: these values are for reynolds only...

The stiffness of a frame is determined by the diameter and length of the tubes. It has little to do with the type of material.
The weight is determined by the wall thickness, which in turn is detrmined by the strength of the material. A super-steel, like 853, can be made strong enough to prevent crush damage, with quite thin walls. A standard steel needs thicker walls.
Thorn's main concern with 853 is that the thin walls are not so resistant to rust and impact damage. It is quite strong enough to use in a touring bike, but expedition bikes get all kinds of extra abuse.
I think they are being a little paranoid, and over-building their expedition models, but better safe than sorry.
Reynoldsusa.com have loads of info on different steels.

Yes that is what I had gathered but Thorn - who are are extremely experienced in this business seem to suggest that it maybe a little too delicate for rough use.

That's true too a point, and here's the point: if your using the 853o/s series tubing it will be more delicate; but 853std tubing is heavier but not delicate for rough use; HOWEVER that's comparing 853o/s to 853std! The only real problem with 853o/s is the thinner walls can be dented easier than std. But read the site I gave you and you can gain some insight on this. I believe 853 is the best steel frame material available although one bike shop said the Colnago Master X-lite uses some sort of special steel (forgot what they called it) that matches the 853o/s. 853st should be more than strong enough for touring.

uh... correct me if i'm wrong, but isn't 853 a cromoly alloy? it's just a special "recipe" known for its strength and weight....

The stiffness of a frame is determined by the diameter and length of the tubes. It has little to do with the type of material.
The weight is determined by the wall thickness, which in turn is detrmined by the strength of the material. A super-steel, like 853, can be made strong enough to prevent crush damage, with quite thin walls. A standard steel needs thicker walls.
Thorn's main concern with 853 is that the thin walls are not so resistant to rust and impact damage. It is quite strong enough to use in a touring bike, but expedition bikes get all kinds of extra abuse.
I think they are being a little paranoid, and over-building their expedition models, but better safe than sorry.
Reynoldsusa.com have loads of info on different steels.
So a steel,carbon,alum and Ti frame,same diameter and tube lengths all having the same group and wheelsets will all ride the same?I'm thinking NOT.

delirious-

The term STEEL in bike-speak generally refers to Cro-Moly, as all generally available tubesets are a steel based alloy which include chromium and molybdenum as well as small amounts of other elements, unique to each alloy. Each "recipe", as you put it, has its own pros and cons.

DEMON

The stiffness of a frame is determined by the diameter and length of the tubes. It has little to do with the type of material.


sooooo two identical tubes, one of aluminum, one steel, are exactly the same as far as stiffness?