titanium blade?

[Karl5]

Are elasticity and brittleness the same thing ?
What about Charpy ?

Nope, not the same thing.

In laymans terms:
Elasticity - how much you can bend something and when you let it go, it'll go back to its original shape.
Brittleness - How easily a material breaks without changing shape first (brittle materials have no "chewing-gum-effect").

A material can be elastic but still brittle - in that case it can bend over a lot, but at a certain point it just snaps without warning.

Charpy - Short for Charpy Impact Test or Charpy V-Notch Test is a standardized test test used to measure how much power is needed to fracture a material. The way the fracture looks (i.e. not the value you get from the test) gives an indication of a materials brittleness.

Clear as mud??

/ Karl

 

[Karl5]

ive used various titanium bicycle components over the years, and not purely because of the light weight, but when used in the construction of contact points.. . bars, stem, seatpost, saddle rails, that kind of thing, titanium gives a kind of micro suspension through its springiness. not suspension with any visible travel, but enough to absorb a degree of buzz or vibration out of the road.

Those components would often be of aluminium, wouldn't they?
In which case it's not directly got anything to do with springiness, but more of design.
Aluminium is prone to fatigue failure (it doesn't like vibrations), and you therefore have to design it so that the parts are stiffer than if you'd use, e.g. titanium.
You as a cyclist will notice the difference in less buzz from the road when changing from aluminium parts to titanium parts because the parts are designed differently, not necessarily because you've got a different material.

/ Karl

 

[big_swede]

Those components would often be of aluminium, wouldn't they?
In which case it's not directly got anything to do with springiness, but more of design.
Aluminium is prone to fatigue failure (it doesn't like vibrations), and you therefore have to design it so that the parts are stiffer than if you'd use, e.g. titanium.
You as a cyclist will notice the difference in less buzz from the road when changing from aluminium parts to titanium parts because the parts are designed differently, not necessarily because you've got a different material.

/ Karl

Well, if you take two frames with the exact same geometry, one in 3/2.5 Ti and one in 7005 Al, you will notice differences over longer distances, given that the other components are the same. Ti has more of a vibration dampening effect, and a more springy reactive feel to it. Also, the Ti is a lot more stiffer. This I have experienced myself.

But on the other hand, a test made by the german magazine Tour (who are the undisputed kings of scientific bicycle testing), which involved having both amateurs and pros ride a set of different bikes, in different materials with the frames covered up, showed that nobody were able to 'feel' the material of the bike.

But all of this is way of topic.

 

[C_Claycomb]

These are the big name in titanium knives
http://missionknive.com/index.php?main_page=page_3

Not exactly the sort of thing to be using for bushcraft though.

 

[Karl5]

Well, if you take two frames with the exact same geometry, one in 3/2.5 Ti and one in 7005 Al, you will notice differences over longer distances, given that the other components are the same. Ti has more of a vibration dampening effect, and a more springy reactive feel to it. Also, the Ti is a lot more stiffer. This I have experienced myself.

But all of this is way of topic.

I agree, way off topic, but I'm still curious.
Were the Al tubes and the Ti tubes on the frame of the same shape and size (diameter and wall thickness and are the tubes butted in the same way)?
I'm not arguing anything, I'm just trying to understand.

And I think the magazine Tour is right, the "experienced" differences between frame materials is most likely mostly a placebo effect.
There are other people agreeing with this also: Frame materials

/ Karl