Road Cycling - has anyone seen ti crack?

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View Full Version : has anyone seen ti crack?


fogrider
05-24-04, 05:52 PM
my friend's front end was feeling a little loose, but he thought it was the wind... this is a merlin (not the extralite) from the mid 90s. My friend is not a big guy, he weighs in at about 140 pounds. I have heard of bad welds failing but not in the tube like this. I guess this is where the shifter bosses are welded in so was that what weakened the tube? :(


khuon
05-24-04, 06:05 PM
Any material can crack. Despite popular perception, titanium is not invulnerable to damage or fatigue. Have I ever seen titanium crack? Yes. There are countless studies and research material on such subjects in the aerospace world.

John Ryder
05-24-04, 06:12 PM
my friend's front end was feeling a little loose, but he thought it was the wind... this is a merlin (not the extralite) from the mid 90s. My friend is not a big guy, he weighs in at about 140 pounds. I have heard of bad welds failing but not in the tube like this. I guess this is where the shifter bosses are welded in so was that what weakened the tube? :(


My 1998 Litespeed Ultimate. 3/4 around the weld on the driveside chainstay near the dropout. Last March I spotted it while I was cleaning my bike...I almost had a heart attack! Anyways I brought it back to the LBS and they shipped it back to Litespeed. 18 days later, got my baby back. I Only paid shipping...Litespeed was awesome.


khuon
05-24-04, 06:18 PM
My 1998 Litespeed Ultimate. 3/4 around the weld on the driveside chainstay near the dropout. Last March I spotted it while I was cleaning my bike...I almost had a heart attack! Anyways I brought it back to the LBS and they shipped it back to Litespeed. 18 days later, got my baby back. I Only paid shipping...Litespeed was awesome.

I have two things to say.

Nice recovery by Litespeed. One of the great things about titanium as a high-end exotic material is that it is fairly repairable but then again the same can be said of high-end steel.

You must do an awesome cleaning job! That part of the drivetrain and chainstay/dropout that I can see looks immaculate enough to serve food off.

John Ryder
05-24-04, 06:36 PM
I have two things to say.

Nice recovery by Litespeed. One of the great things about titanium as a high-end exotic material is that it is fairly repairable but then again the same can be said of high-end steel.

You must do an awesome cleaning job! That part of the drivetrain and chainstay/dropout that I can see looks immaculate enough to serve food off.




The only thing Litespeed couldn't repair would be a crack in the BB going up the seat tube.

Thanks for the cleaning review...Yeah, It usually takes me about 2 hours to clean my bike, everything including drivetrain. And I clean it once every couple of weeks. And yes I DO ride it...outside. ; )

OneTinSloth
05-24-04, 08:13 PM
that merlin crack makes me want to cry. :(

and that litespeed (despite what i've said in the past about litespeeds) is rather sexy...

i need a new frame.

Hunter
05-24-04, 11:12 PM
I have seen Ti. twist like a rung out wash cloth.

Thylacine
05-25-04, 12:09 AM
Quite a few of the older Merlins crack at the STI Bosses. The reason is simple. The weld area of the boss is too small, and it's welded in the highest stressed part of the tube. It's why a lot of companies now weld the bosses to the head tube. Also, I'm not a huge fan of the bullet ends - much prefer the Wright style dropouts, for the very reason shown above. Nice of Litespeed to reweld it for you, though.

kevmetric
05-25-04, 02:13 AM
The advantage of light weight of Titanium is more than
taken away, by the lack of strength of the metal. It is very light,
but very maleable ...it can bend around like putty or bread dough,
almost. Scary stuff....

At least with cro-moly, the steel will wax and wane, bend and come
back easily, reliably and predictably time and again - unless you actually
wack it with a sledgehammer or take a steel saw to it. Otherwise, it won't
bend from common biking usage.

Avalanche325
05-25-04, 03:38 PM
JUST SAY NO!!!!!
I haven't seen titanium crack myself.
I don't know if titanium crack is better than regular old crack.
How much does a rock of titanium crack cost anyway?

John Ryder
05-25-04, 08:15 PM
JUST SAY NO!!!!!
I haven't seen titanium crack myself.
I don't know if titanium crack is better than regular old crack.
How much does a rock of titanium crack cost anyway?


The crazy/scary thing about it was I am not sure how long I rode my litespeed before I did notice the crack in the chainstay. All Litespeed did was chop out the old chainstay and put in a new one...not just a re-weld of the same chainstay...then dye tested all the welds and also checked the frame alignment, re-brushed the whole frame and re-decal it as well. All that in 18 days.

slvoid
05-25-04, 10:38 PM
If you look at the fracture surface, generally if it's got flat sheared off areas, it's overloaded. If it's rough and matted, it's fatigued.

RacerX
05-26-04, 01:53 PM
The advantage of light weight of Titanium is more than
taken away, by the lack of strength of the metal. It is very light,
but very maleable ...it can bend around like putty or bread dough,
almost. Scary stuff....


...which is why there are no bikes, aeroplanes, vehicle structures made of pure titanium. Hence, 6/4 Ti, 3/2.5 ti. Introduction of other components make ti frames the best material to make bicycles out of.

Just like there are no pure aluminum frames or pure raw steel- both are soft as hell too right?

Even carbon fiber requires resin as the stiffening agent. Pure carbon (powder) is just a cloth in "raw" form for bicycles.

slvoid
05-26-04, 02:14 PM
...which is why there are no bikes, aeroplanes, vehicle structures made of pure titanium. Hence, 6/4 Ti, 3/2.5 ti. Introduction of other components make ti frames the best material to make bicycles out of.

Just like there are no pure aluminum frames or pure raw steel- both are soft as hell too right?

Even carbon fiber requires resin as the stiffening agent. Pure carbon (powder) is just a cloth in "raw" form for bicycles.

I thought pure carbon as a powder would be something like coal. The cloth itself is made of many fibers of carbon of which each are woven from filaments of carbon of which each are molecular strands. A lot of metals are alloyed or treated to a specific crystalline arrangement to achieve their miraculous strengths and hardnesses.

RacerX
05-26-04, 03:01 PM
Which is my whole point! It is misleading for someone to state that titanium "can bend around like putty or bread dough, almost. Scary stuff...."

jfmckenna
05-26-04, 06:39 PM
I used to get Ti Stick But I've never seen the Ti Crack.

PeaWee
05-26-04, 06:55 PM
...which is why there are no bikes, aeroplanes, vehicle structures made of pure titanium. Hence, 6/4 Ti, 3/2.5 ti. Introduction of other components make ti frames the best material to make bicycles out of.

Just like there are no pure aluminum frames or pure raw steel- both are soft as hell too right?

Even carbon fiber requires resin as the stiffening agent. Pure carbon (powder) is just a cloth in "raw" form for bicycles.

Steel is of itself an Iron alloy, the different steel names (cro-moly, etc) describe the different mixtures used in its creation. If you want a wraught iron bike... it'll be strong, but, you know, the 60 pound frame will be hell in the hills