T4tomo
Legendary Member
can you post of link of a Giant bike with a titanium frame?
Ti crack
- Thread starter Ian H
- Start date
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Dogtrousers
Kilometre nibbler
That seemed like a challenge (one that I pretty much knew would fail, but hey ...)
Amusingly I came across this. The Giant Reign 29 2 Titanium https://www.paulscycles.co.uk/bikes/mountain-bikes/giant-reign-29-2-titanium__5628
Unfortunately "Titanium" here refers to the colour. It's in "Black Titanium" (What?)
Frame is Al
rogerzilla
Legendary Member
Titanium, like steel, has a cyclic fatigue limit. In a nutshell, this is a stress below which the metal will not (theoretically) fatigue even after an infinite number of stress cycles. The fatigue limit is around half the tensile strength.
There are three problems with this:
1. The limit is much lower where the metal has been affected by welding heat
2. The stresses on a frame are unpredictable and can be very high, e.g. when hitting a pothole. These big hits gradually add up if they are above the fatigue limit.
3. There is some scientific debate over whether a fatigue limit really exists as it is normally understood, or whether everything eventually breaks - steel and titanium just taking a lot longer
There are three problems with this:
1. The limit is much lower where the metal has been affected by welding heat
2. The stresses on a frame are unpredictable and can be very high, e.g. when hitting a pothole. These big hits gradually add up if they are above the fatigue limit.
3. There is some scientific debate over whether a fatigue limit really exists as it is normally understood, or whether everything eventually breaks - steel and titanium just taking a lot longer
matticus
Guru
@Dogtrousers : do you think we should have a Ti-vs-Al-vs-Carbon fight discussion here? Some groundwork is already in. I feel it could be useful - what say you?
T4tomo
Legendary Member
Indeed, maybe @bonzobanana will have the grace to apologise for calling me a childish moron, who knows?
Ajax Bay
Guru
- Location
- East Devon
Only if the 'groundwork' is well founded with minimum ad hominem addititives
only what I've read from cycling sites, books and forums
I'll admit I don't know how fatigue works
titanium frames have got much lighter
Butted tubes is [sic] definitely about saving weight
Giant clearly state performance frames have shortened lifespans for the performance gains.
Making titanium lighter with butted or milled tubes will obviously weaken them.
a frame being used with thinner tubing will be more vulnerable
Lifetime warranties are often mis-understood
Many titanium frames now are performance frames optimised for low weight
many titanium frames are in aluminium or even CF weight territory.
Smokin Joe
Squire
- Location
- Bare headed cyclist, Smoker
Yellow saddle, late of this parish once wrote a long piece on why Ti was an unsuitable material for frames. No opinion myself as I've never owned one, but he was some sort of engineer. A forum search should unearth it.
matticus
Guru
T4tomo
Legendary Member
Ajax Bay
Guru
- Location
- East Devon
Here you are:
https://www.cyclechat.net/threads/hold-buying-that-titanium-frame.232057/page-2#post-5433856
and a taster:
"Titanium is a much-hyped material. Probably the most hyped-up material other than carbon fibre.
"It is steeped in mystique, right from being named after the children of Uranus and Gaea in Greek mythology, through to scarcity during the cold war. It is said that Ronald Reagan and Michael Gorbachev sealed the end of the cold war deal on a golf course somewhere by teeing off with a set of drivers made from titanium - supposedly repurposed missile shell skin. I dunno, but that's how deep the titanium lore goes."
He was also very opinionated and didn't like been proved wrong.
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
7 years for a frame is poor. I'd be hissed off if my 30year old Columbus or Reynolds steels cracked. At least Ti is repairable.
Smokin Joe
Squire
- Location
- Bare headed cyclist, Smoker
Now that's unusual here
There is member who worked for a well known British Ti bike outfit for over 10 years. During one of his posting on unrelated matter he mentioned he had 2 Ti bikes and both were Van Nicholas. I was not surprised.
The problem was specialist weld expertise needed in the UK at the time and not surprisingly one joint will fail and then later another.
The bike in question here is not weld but design failure. Terrible company and explains its closure.
Welding technology has caught up in the UK and no longer a problem. Planet X etc are doing well in Ti. In those days it was Dutch or the Americans.
To be honest, the forum is an awfully nice place and people do not want to offend. The guy who did the repair was responsible enough to treat the other side because the design issue will certainly follow. He should have recommended a write-off instead.
The problem was specialist weld expertise needed in the UK at the time and not surprisingly one joint will fail and then later another.
The bike in question here is not weld but design failure. Terrible company and explains its closure.
Welding technology has caught up in the UK and no longer a problem. Planet X etc are doing well in Ti. In those days it was Dutch or the Americans.
To be honest, the forum is an awfully nice place and people do not want to offend. The guy who did the repair was responsible enough to treat the other side because the design issue will certainly follow. He should have recommended a write-off instead.
There has always been some top Ti welders in the UK, why they are not employed in the cycle industry I suspect is because the don't pay anything like what they can earn elsewhere.
A passionate UK Ti frame builder/welder would be doing it because he loved it IMO.
