Titanium - strong enough?

[24pouces]

For the bolts, titanium isn't a good material…
I Titanium love flex, it doesn't love to work in twisting. Some first titanium BB and pedal spindle broke. It's the same think about bolts…
For a spindle or a BB, you need a bigger titanium diameter from the same item made in steel.

 

[hamster]

To use Keith Bontrager's saying:

"Light, strong, cheap...pick two"

The fact is that too much Ti stuff has been sold simply because it's Ti, rather than appropriate for the job. I have a 1994 Litespeed Catalyst, which is still fine..but overbuilt by modern standards.

I've seen several other threads (sorry can't remember where, possibly Bikeradar) which have XACD's with torn seat tubes.

I think that the problem is that XACD may not have sufficient experience to design correctly a durable frame. I've done a lot of business in China and many people copy but don't understand what they are copying. I've come across copies of Panasonic components where they've even copied holes etc which are non-functional but part of Panasonic's assembly process - and unused by the Chinese copycat.

 

[stevet1]

For a spindle or a BB, you need a bigger titanium diameter from the same item made in steel.

Exactly. The only exception is when a part is overbuilt in the first place, I recently swapped out a steel axle on a pair of Primo BMX cranks for a Ti one but thats because its absolutely massive and I'm certain it'd withstand a nuclear explosion.

 

[Wold Ranger]

Titanium

Couldn't agree with all of the above more! But I feel must add with a lot of far Eastern frames, the MTB press are very guilty of quoting frame/bike reviews along the lines of "Good as a Merlin, Seven or Litespeed for a grand less" this is usually for a far eastern Ti frame.
Sevens, Merlins and litespeeds take a day to weld up, as they weld a short run, then leave to cool before proceeding and no one joint is welded continuously.
Its much the same with the bolts too, some are far better than others, price often dictates which, Venhill engineering used to make some very very good ones and I have e that have seen many bikes and have never galled, worn or had there allen slots damaged, they are far harder than most steel bolts, but were pretty expensive back then.

 

[FluffyChicken]

Surely the type and grade of the Titanium alloy has a great bearing on this, just as the Steel 'alloy' grade has.

I really doubt you are using pure Titanium

 

[reanimation]

Wow what an interesting thread. Jbiker sorry to hear of your pain and TBH many of us could make a similar mistake, you seem to just have a thread full of people who seem to know about this stuff.

TBH this explains why
a) I cant find many seat posts or stems FS from known people in Ti
b) cant get a Ti frame I like less than 1k

not that i can afford this stuff anyway

The choice of material thing is valid thinking about it, the how things are made thing is very important too think about everything, food to buildings, and the design copy thing reminds me of this fake Vauxhall frontera http://uk.youtube.com/watch?v=DZWy_fASSiQ :shock:

Glad you are still alright JB and hope this thread educates a few of us (inc me)keeping us safe

 

[sq225917]

JB i was going to recco Omega, they'll fix it easily.

Though to be honest it is probably put together from the titanium equivalent of scaffolding pipe, seamed checmical tubing.

 

[konahed]

Surely the type and grade of the Titanium alloy has a great bearing on this, just as the Steel 'alloy' grade has.

I really doubt you are using pure Titanium

I doubt anybody is.

 

[Xesh]

Though to be honest it is probably put together from the titanium equivalent of scaffolding pipe, seamed checmical tubing.

That's pretty much what some of the Dynatechs used. Iirc it was called CP titanium (with the CP standing for commercially pure). There was also some question about the life span of frames made using it. AfaIk the life span of these frames wasn't expected to be much more than a good quality alu frame. The addition of the aluminium and vanadium increases the fatigue life of the metal which is why we have different alloys.

 

[Benandemu]

Interesting how so many people assume Titanium to be a metal used on its own, when it is actually an alloy in our case.
It is a highly complex metal that should always be manufactured as an alloy with bicycle components. Plus it should be considered whether the ti is in a high stress area, should it be hardened, what stress the component will receive, and how heavy the rider is.
Ti is no different from steel really. Think of it like cheap tools and expensive tools. We all know the difference is in the grade of metal and the treatment of it during manufacture. How many times have you rounded a cheap screwdriver or socket? Cheap steel and cheap manufacture v's complex steel and expensive manufacture. The principles are the same. Consider its makeup and its destined use. Many of the ti bolts on offer today are pure or 3/2.5 which is just not suitable for stress applications. A good seller will responsibly inform you whether they are suitable for your intentions. That's why there is such a big difference in prices between them all.
I have used ti bolts and equipment for decades and in high stress areas with absolutely no problems (I weigh 13 stone by the way). The key difference is to understand the metal mix and its limitations in all destined purposes, and choose carefully which is suitable for you. Hardedned 6Al 4V is best for bolts and skewers. But it doesn't come cheap or torque up like steel!
With frames, you do generally get what you pay for. Hate to say it, but I know some importers of far eastern frames and they reject more samples than they accept when browsing the 'so called' factories for a stable supplier. They have described some absolute horrors from their trips. The craftsmanship is simply not the same.

Really sorry to hear about your breakage and hope some research gives you an excuse to replace the broken parts with exotic ti bits.