metallurgist question

[OB_Mr Bear]

I can't answer any of your questions.

BUT, there is more than one way to skin a cat. Someone would have to actually design a, for instance, titanium frame for a Hayabusa, before anyone could put a weight number on it. Titanium has different characteristics than the aluminum alloy used in the stock frame. Titanium is actually a somewhat spongy metal. It tends to compress and bounce back a bit under loading. It is very hard, and has very high tensile strength.

The point is, designing a different frame for the Busa would be no brief task. All the weights and loadings would have to be recorded and calculated, dimensions and wall thicknesses specified, matched up against the specs for the material used.

It is a simple question with a simple answer, but the process of deducing that simple answer is very complex.

 

[Guest]

I know it would probably be cost prohibitive, but I gotta ask;
a) what does a busa frame weigh?(anyone)
b) what would a magnesium or titanium replacement frame weigh?
c) would it be really expensive and worth it?
d) would it be as strong?

curious...

 

[OB_BarryW.]

Well put Mr. Bear.

'Lanta:
It's difficult to assess different weights based on material properties alone. For example, Aluminum is actually lighter (less dense) than Titanium, however it has much lower strength and consequently you'd need more of it at any given cross section to match strength. Aluminum and Titanium are closely matched for elasticity (Ti is a little stiffer), but are only about half as stiff as even the weakest steel. Since chassis stiffness is as important as weight, you'd need more Ti and Al than steel for a given cross section to match stiffness. Wrought Magnesium alloys have the highest mass-specific stiffness of all the materials you mentioned, but also has the lowest strength.

The final material selection includes many factors, such as material cost, forming cost, weight, size. I'd say look to the world of GP bikes or any series where money is absolutely not an issue to find out what the ultimate material would be. I believe GP bikes use Aluminum frames, but bear in mind that Ducatis still use "old fashioned" steel tube frames, even at the WSB level.

This oration is simply an engineer's way of saying "Hmmm, I don't know." LOL