Titanium Longevity
 

Why is it that whenever this notion of someone wanting a bike to last them forever titanium always seems to be the material suggested?
Is there any proof that it has better durability/fatigue resistance than other frame materials?
I certainly know people that have cracked frames (fatigue) of all materials, including titanium.
This is obviously only a small sample size though as it is just the people I have met.

I bet if you did full forensics on the ti frames that have broken you would find workmanship or design issues or simply too light a frame for the job in almost every case. Titanium, like steel, has a fatigue limit. Keep stresses below that limit and it will remain fatigue free for a very long time but get sorta close then add some welds that aren't executed very well, perhaps thinning the tubes adjacent to the weld ends in a place unseen and the stresses there now start creeping above the fatigue limit. Ride this bike long enough and the crack starts. Poor design of stressed areas may have the same outcome even if the workmanship is good.

The workmanship required to do ti right is not a trivial matter. By comparison, a lugged steel frame is incredibly forgiving.

Ben

Good comments by Ben...

Dean, I believe its part perception which may not be completely grounded in fact as you imply. I sure don't believe Ti is really any more bulletproof than Steel or Al.
But compared to carbon because the matrix is a resin aka polymer or plastic...this ties in a bit to perception as well...metal is more robust than plastic. But is it really?
Boeing makes an airplane out of carbon fiber for example.

The knock on carbon fiber is abrasion resistance which is true...carbon scratches deeper easier than a metal frame...but also impact resistance which really is a bit of a bad knock. Yes carbon may crack based upon a hard crash, but metal will pretzel under the same forces. Both frames end up getting trashed.

I have owned every material and had great luck with each. I like them all honestly. I prefer carbon fiber for pure performance in a frameset and Al for best performance per dollar. I find Ti to be a bit heavier...and steel...if either frame is built with durability in mind.

My current carbon road bike is now about 6 years old and has about 40K miles on it. It still is in perfect condition. I have had two crashs riding since owning it where I went over but didn't hit anything. I don't have any plans to replace it current time. I know good riders with 100K miles on their older carbon fiber framesets...these guys ride a bit more than me and I ride about 5-6K miles per year.

Subscribed.

I think the wide-angle lens view is that steel is durable, but heavier than other materials and can of course rust. Aluminum is lighter but has fatigue issues with LONG use. Carbon fiber is fine but if you crash or drop it, the material will break. Ti is lighter than steel, should not fatigue or rust, and if made properly should last a long time. Of course some metals can become brittle and if not made properly it can break.

So each material has something really good to offer and (of course) some drawbacks. Nothing is perfect.

That said, when I got my "forever" bike I did choose Ti.

+1.

My fears with CF are more that I've been told (but have no firsthand proof it's more of a problem than other materials) that it's possible to get damage that can severely impair structural integrity but isn't visible to the naked eye (at least I've been told that metals are easier to see bends/rust holes, etc.), and the fact that UV light degrades plastics (so therefore CF?). But that's not the reason I don't own a CF bike. It's more that I'm cheap and I like the looks of lugs and shiny chrome, which limits me to used bikes. I'm not anti-CF by any means, just don't own any bikes made out of it (though one of my old steel bikes does have a CF fork).

When I got my wedding ring a long time ago, I got one made out of Ti because the guy at the jewelry store sold it to me as the strongest metal that had a ring made out of and there was symbolism in that. Plus, it looked badass and I was in my early 20's and that was important to me.

Now, material is material and each serves its purpose.

I agree with all of this. I currently have Ti, carbon and steel bikes and have enjoyed them all. However, I ride the Ti every day and even when I plan to ride the carbon, I end up bringing the Ti instead, even on hilly rides.

Same experience with me. I ride a Merlin (pre Litespeed) that I bought new in 2000. My Orbea Orca 2012 is a super bike and stiffer and lighter in weight but the ride quality of the Ti bike is, well, I know that the term superior is pretty strong but I have to say that the Ti bike floats over the harsh stuff. I ride a lot of steep hills here, many 12% to 15% and others more relaxed at 8% and when ever I grab the Merlin, I find that it just goes up those climbs very nicely.

Campagforlife is correct in identifying the damage from impacts that will make the CF a bit more vulnerable vs the Ti bike but again, you can't generalize all circumstances. I don't see myself replacing the Merlin any time soon. Or the Orca for that matter.

How does it compare in weight to Carbon?

And yet there are a gazillion steel, aluminum and CF bikes out there that have lasted a very long time. There aren't a gazillion, but maybe a bazillion Ti bikes too. But the failures we read about on the forum are the ones that make up our minds. Short of a crash, all the materials will last a long time.

I myself ride a CF Kuota from 2005, an aluminum Trek mtb from 1990 and a steel Davidson from 1981. All are getting old and all are fine.

I should add that the Trek is a bonded aluminum frame, not a welded one, and these were not thought to last. I haven't had any problems using it as my commuter.

Who cares?

It really just doesn't matter except for maybe bragging rights. I mean, unless you're talking about a significant weight difference, 1 or two pounds is trivial when you put a rider & water bottles on that thing.

A number of years ago (when I was riding a Ti bike) I found some german study that fatigued a bunch of bikes of different materials and Ti was definitely not superior to the other frames. I was disappointed at the time, having been delivered to the church of Ti is superior by my mistaken emotions but I got over it.

On group rides, I've noticed the Ti riders discussing their frame repairs,

more so than other materials, in my limited sample.


I also read & hear folks talking about how (usually steel) is great because it lasts forever,

but they are never riding their '70s Peugeot from back in the day- they've upgraded multiple times since.

My Ti bike is becoming my favorite ride. I have CF and Al. I bought a Bikes Direct Ti bike used and upgraded it with 11 speed 105 stuff. Great bike!

The reason Ti is rumored to last the longest is that Ti is twice as flexible as steel, so bending moments that might go past a steel tube's elastic limit will still be well within Ti. For this reason, Ti is a real pain to cold set - you have to bend it much farther for the bend to remain. It is essentially more "rubbery" than steel, but can be oversized to similar stiffness.

That advantage is also true in directions where carbon fiber is typically not strong - like side impacts on the tube. A good wack on a top tube may make a bigger dent or bust a CF tube, but will leave less of a dent on Ti.

That said, Ti is the most sensitive bike material to welding cleanliness (but not to heat cycles), so most Ti failures come from polluted welds. You'll virtually never see a Ti frame that failed nowhere near a weld or Heat Affected Zone where a nugget of oxide formed in the metal. But I've seen plenty of steel bikes where riding work hardened and cracked the chainstay well away from the BB.

For a bike that is pleasantly flexible rather than ultrastiff, Ti will take more work cycles and impacts than other materials. But any frame that is stiff or thick enough will last even longer - it just won't be pleasant to ride.

I think you're referring to this test? Very interesting 12 High-End Frames in the EFBe Fatigue Test

All the ti failures came from welds in that test.

That sure looks familiar! And my Ti bike was in fact a Merlin Road.... ca 1990 I reckon. The welds on that thing are gorgeous.

It doesn't really matter if the failure is at a weld or somewhere else. It has still failed.
If it can be welded by some elite few without the joint being a problem I guess you need to find out who those frame builders are, somehow.
As you are no doubt aware there are many steel alloys that have been developed for the sole reason of being reliably weldable.
Also other processes (brazing, lugs) for those alloys that can't be welded.

Trek OCLV: the forever frame.

It's not a question of elite skill, just prep and cleanliness. Weld it clean and bike will take many, many more cycles than the most perfect eqivalent riding steel frame. Get nitride in the weld and a Ti frame may not last a month.

That doesn't mean steel is bad or you need to love Ti, but it is the pertinent facts to the discussion.

Steel is real.

I had thoughts much the same as Dean. If the material is so temperamental that it fails even in the hands of reputable makers, as shown here, what's the difference?

So 18 years ago I bought a steel bike, a friend already had a TI Seven for a couple of years, and another friend bought a Trek One carbon frame.

The Ti bike is his sole form of transportation, so it has the most miles. Probably 200 miles a week average. Still going strong, despite at least 4 serious crashes requiring hospitalization and being hit twice by a car. Frame did not take any damage above a little road rash.

My steel frame is still going strong, one minor ding.

The Trek One is long since dead.

Well, I doubt that a statistician could poke any holes in that. Kudos.