Ti frames - why do they break and ride with steel

samsbike

I keep reading how Ti are frames for life, but I have read about frames cracking? Why is that, are they so light that strength is comprised? To be honest I have not heard of steel frames cracking in the same manner.

Also, what is the difference in ride between Ti and steel?

Thanks

estampida

its not as straight forward as that

ti frames, as they are that flexible, it possible they have been really flexed and you could not tell there was any damage until the crack turns up

welding ti uses TIG welding, very dependant on the ability of the welder and the hygiene of the building practice (the electrode must be free from contamination)

ti frames tend to have 3al/2.5v tubing but 6al/4v drop-outs the 6al is a lot stiffer so all the flex in the tube, the stress will be centred on where the flex stops causing premature failure

and the stuff can be a pain to hydro-form, with shrinkage and work hardening all taking its toll on the tolerance and ultimate design strength of the structure

also you get people who run out of talent way too quickly on a ride and use the ill though out defence

"oh ti is ment to be indestructible".....

topdude

Ti does not suffer from corrosion therefore it will last a lifetime (unless it breaks) !!
Steel is probably made from thicker tubing with strong joints so it will last a lifetime (unless it rusts) !!
Aluminium oxidises but does not corrode, formed into very thin walled tubes it can dent or crease easily.
Carbon does not suffer from corrosion so could last a lifetime but i've lost count of the broken carbon frames seen in this forum !!
As for Ti ride quality i can only compare with an alloy frame, i had a VN Euros, rode it for a couple of years, it seemed ok but i wouldn't say it was a magic carpet ride. Changed to a Giant Defy and instantly felt the difference, the alloy frame had a harshness / road vibration that was not there on the Euros. I suspect a decent butted steel frame is probably so close to Ti that the difference is minimal.

MattC59

Titanium is a b*tch to weld properly, poorly welded Ti can introduce weaknesses to the structure.

A good builder will be confident in offering a no quibbles, lifetime guarantee against manufacturing defects / materials.

awsm

Most Ti failures result from as already mentioned poor welding. Worth buying from a quality builder especially if they offer lifetime warranties on defective frames.

Monty Dog

The majority of problems with titanium frames are either down to poor design e.g. welding big thick sections of plate or tube to thin-wall tubing - flexion of the joint creates premature failure; or due to poor weld quality creating stress-raisers. Done properly however, titanium has the ability to create a robust frame with an almost infinite fatigue life - I've been riding titanium frames for 12 years and yet to break one e.g. I've just spend this afternoon battering my way along 50km of bridleway and green roads on my titanium CX frame - fist-sized flints were bouncing off the downtube.

woolwich

+1 to the previous comments. It is poor design or manufacture that causes ti failure and not the material.

Also it is not uncommon for steel frames to crack, if either the design is weak or the manufacture dodgy. Modern butted steel tubing can be as thin as 0.38mm and strength is compromised for weight as you suggest. No problem/excellent for certain applications. Terrible for something like a seat post on a 29'er MTB for example. Many steel frames have cracked at the seat clamp stress relief hole due to poor tubing choice.

compositepro

And a lot of titanium tube is shite straight from the mill

CWSR grade 9 is definitely not what it was 10 years ago

springtide9

topdude wrote:

Ti does not suffer from corrosion therefore it will last a lifetime (unless it breaks) !!
Steel is probably made from thicker tubing with strong joints so it will last a lifetime (unless it rusts) !!
Aluminium oxidises but does not corrode, formed into very thin walled tubes it can dent or crease easily.
Carbon does not suffer from corrosion so could last a lifetime but i've lost count of the broken carbon frames seen in this forum !

Untrue (bold text). As an owner of a Cannondale MTB frame that seat tube 'perforated' due to corrosion, aluminium although better than steel for corrosion, are not corrosion free. It was noticed when the frame was stripped for painting, and apparently it's not that uncommon.

MattC59

topdude wrote:

Aluminium oxidises but does not corrode

Eeeeerm.......... Oxidisation is a form of corrosion.

rolf_f

Monty Dog wrote:

I've been riding titanium frames for 12 years and yet to break one

This would be more impressive if the titanium frames were in the singular