BostonFixed

I have a MTB flat bar that I aquired, and I suspect that it might be made out of titanium. Are there any ways to figure out what the bar is made out of?
There are no decals/markings/labels/logos/etc. on the bar, so that complictes things further.
Any ideas?
Suggestions?
Thanks.

Dirtbike

Its most likely to be a no-name bar if it doesnt have a single decal. If it was expensive enough to be made of Ti, it probably would have at least some sort of decal indicating so. A bar made out of Ti will feel like a feather in your hands.

2manybikes

The decals can be taken off easily, some have only one decal and it comes right off. I'm sure you know they are not steel and not magnetic already. The ti bars file and cut harder than aluminum, much harder, but they can be cut. Find an aluminum bar, gently scratch it someplace it won't matter like on the very end of the tube, and then immediately do the other bar. It will be different. It will be much harder to scratch the ti bar. Maybe use a nail to do this. Don't make a deep scratch anywhere, that could make a stress riser. Just scrape the very end of the bar where the tube was cut.
Also the ti bars are not the same color as the aluminum ones they are a lot browner and less silver. If they are right next to an aluminum bar they are easy to see as browner.
Also some of the ti bars do not have a clamping bulge, they use a shim instead for the stem.

Dirtbike

Some bars, like ProTaper bars for dirtbikes, have what they call "unstickers" they are laser etched or something and wont scratch off.

BostonFixed

My bar has this shim dealie for clamping, which tipped me off that it might be ti. Thanks for the info!

Rev.Chuck

Ti stuff is usually unfinished, so it would have a dull gray almost plastic look. If a magnet sticks, it is steel If it has a silver finish probably alluminum. If it is painted or anodised, probably alluminum

2manybikes

If it is a black shim and very nicely finished almost to feel like plastic, even though it's probably aluminum,
it may be a White Bros. "TiBar", this comes with just one easy to remove sticker on the bar. Easy to take off if one had to leave the bike locked ouside in Beantown, for instance. I think I have seen them for sale at Harris. Also down here In R.I.

Mr.Endo, Esq.

Nonsense. Given equal mass, Ti is heavier than alum.

slvoid

So you're saying that 1kg of Ti is heavier than 1kg of aluminium...

Mass is how much of a substance in something.
Weight is how that something is being pulled down by gravity.

The reason why we use mass is, if I sell you 1 kg of copper here, it's the same 1kg of copper in space with no gravity. A 250gram bag of chips is still 250grams on the moon with 1/6th the gravity.
But if I sell you a piece of copper that weighs 9.8 NEWTONS, then yes, at sea level, it's roughly 1 kg, on the moon, I could be ripping you off.

I think you meant given equal volume, Ti would be heavier than aluminium.
For a cube of material 1m^3, titanium sits around 4.5kt, aluminium is 2.7kt, magnesium 1.7kt, and lead 11.3kt. The lesson here is, lead does not make a good bike material.

Titanium has a modulus of 120GPa, aluminium is about 70GPa in terms of stiffness.
Titnaium yields at 925 MPa, aluminium can yield at 450+ Mpa.

Titanium is heavier but you use less of it. Depending on geometry, stiffness constraints, etc, you can have a heavy ti frame or heavy al frame or vice versa.

2manybikes

That's not logical Captian.....

Mr.Endo, Esq.

Mea culpa. Volume, man, volume.

sirwilliamjr

Actually, it could be, depending on the rider. If two riders start out with handlebars of the same mass, the rider that's going faster is going to have a heavier bar. Of course, the change in mass will be negligible until he approaches the speed of light.... At least, thats how I understand the theory of relativity (however, I'm not a physicist...).

-Will

Peek the Geek

Heat the bar until it melts, and note what the temperature of the bar is when it melts. Compare that temperature with the known temperatures of aluminum and titanium.

allgoo19

Take it to the recycling center. If they don't give you anything, it's probably steel, if they give you 50 cents, it's propbably aluminum, if they give you $3.-, it's likely titanium.

slvoid

Titanium has a thermal conductivity coeff of 0.041, aluminium has one that's an order greater at 0.49, meaning that if you had to choose a freezing cold toilet seat to sit on in the south pole, pick the titanium one.
Or if you have a really really good ohm meter, titanium is 55 micohm's per cm while aluminium is 2.7.
Or if you have a really accurate pair of calipers, the expansion coeff is 8.4E-6 while AL is 23E-6.
Specific gravity is 4.5 for Ti vs. 2.7. So if it's a solid continuous cylinder, you can calculate the volume and see how much it is vs. water.
Or if you'd rather go with a destructive method, try Peek's, melt it.

2manybikes

So which is heavier, 1kg of Ti or 1kg of Aluminum?

darkmother

Take a look at the wall thickness. Aluminum bars have to be quite a bit thicker than Ti. Additionally, you could try to scratch the bar. Aluminum will scratch fairly easily, Ti is harder.

slvoid

According to this guy, titanium.
https://www.bikeforums.net/showpost.p...86&postcount=8

slvoid

That also works.
If you don't want to horribly gouge the handle bar, you can take a piece of glass and if you can find a bare surface at the end, try scratching it lightly. Aluminium oxides and forms aluminium oxide on the surface (sapphire, ruby, etc) which is extremely hard, you shouldn't be able to lightly scratch sapphire with glass. I think the titanium oxide layer is 2 lower on the hardness scale but I could be wrong.

2manybikes

I should have posted a smiley, I was teasing you about all the info you posted about titanium and aluminum. How in the world did you know that?