Bicycle Mechanics - Stronger Material?

http://www.bikeforums.net/showthread.php?t=56017 <<That is a recent post I cant seem to get an answer to (The post is mine). I would like to know if the Chromoly (Sorry if it is misspelled) or Titanium is a stronger material.

There are guys on this forum that know much more than me, but since no one's answered you.........

I got this off a web-site:
* Titanium weighs about 60% of steel.
* Titanium is stronger than steel by weight.
* Two identical sized parts, one steel and one titanium, the steel part is much stronger.

So, same size tube, steel is stronger but much heavier.
Same weight tube, Ti is stronger.

What size/style frame is it gunna be? BMX, road, cross, mountain?

Do any pro "rampers" use titamium?

One thing's for sure, titanium is a gazillion times more expensive.

http://www.bikeforums.net/showthread.php?t=56017 <<That is a recent post I cant seem to get an answer to (The post is mine). I would like to know if the Chromoly (Sorry if it is misspelled) or Titanium is a stronger material.


Too keep this answer simple: The most common titanium alloy used for bicycles is 3/2.5 which has a similar strength to basic 4130 chromoly steel.

But for the price of the lowest grade Ti bike, you can get a Reynolds 853 heat-treated steel.
Advanced heat treatment can double the tensile strength of steel compared to basic chromoly.

http://www.reynoldsusa.com/

Hi,
strength is as much a function of design and construction as it is a function of the raw material. By that I mean the way the bike is put together is more important than what it is put together with.
Steel is cool. Titanium is also cool. I have both a Ti bike and a steel bike. I am thinking of getting a custom bike because I am an odd size, for $$ reasons it would be steel. Hope that helps.

http://www.bikeforums.net/showthread.php?t=56017 <<That is a recent post I cant seem to get an answer to (The post is mine). I would like to know if the Chromoly (Sorry if it is misspelled) or Titanium is a stronger material.

Are you buying a bar of material or you buying a bike?

I can take the strongest material in the world, whatever that might be, and it will surely break if I don't use enough of it.
I can take something that is significantly weaker and it won't break if I do it right.

http://www.bikeforums.net/showthread.php?t=56017 <<That is a recent post I cant seem to get an answer to (The post is mine). I would like to know if the Chromoly (Sorry if it is misspelled) or Titanium is a stronger material.

Like life, there is no simple answer to this question.

I briefly looked at the yield tenisile strength of a Titanium Alloy (3 Al, 2.5 V) which from memory means Titanium with 3% Aluminum and 2.5% Vanadium. And I compared it to Steel with Chrome and Molybdenum (4130). Another poster mentioned these are the typical alloys. The tensile strength is the materials capacity to withstand a "pulling" force. Yield refers to the capacity at which the material begins to stretch but will return to it's original dimensions when the force is removed.

1. Ti 3Al, 2.5V: yield strength ranges from 72,500 to 120,000 lbs per square inch (psi) of material. In other words, a solid one square inch of material will withstand 72,000 to 120,00 lbs of pulling force. This range represents 4 different post treatments of the material (like annealing, cooling rates, tempering...). 3 of the 4 treatments result in the mid 70,000 psi. One of these 3 are probably the type used in bikes

2. 4130 yield strength ranges from 58,000 to 138,000 psi. 4 of the 8 post treatments result in the mid 60,000 psi. One of these 4 are probably the type used in bikes.

3. Let's assume Ti 3/2.5 has a yield tensile strength of 76,000 psi. Likewise, 4130 is 62,000 psi.

4. The huge difference is in it's density. A one inch cube (cube 1" x 1" x 1") weighs:

Ti 3/2.5: 0.162 lbs
4130: 0.284 lbs

5. Per #3 above the Ti 3/2.5 is about 25% stronger than 4130. But per #4 for the same volume of material, Ti 3/2.5 weighs about half. In other words, the "strength to weight" ratio of Ti 3/2.5 is about twice that of 4130.

6. Of course, this only looks at the tensile strength. There are many other properties that should be considered, like fatigue life, shear strength, compression strength, material toughness, brittleness, corrosion, weldability... all need to be considered when evaluating materials.

7. If you really want to be accurate, you'll need to know the composition of the alloy (like Ti with 3% aluminum and 2.5% vanadium) and the exact treatment process of the alloy.

8. Yeah, like life, no simple answers.