Viewing 33 posts - 81 through 113 (of 113 total)
  • chinese titanium versus usa titanium
  • hora
    Free Member

    Druidh you seriously need to sort the moss out 😕

    Travis
    Full Member

    Hi, I’ve been in-touch with the factory, they gave me an email address of a gentleman (?) in Holland who is the European dist. Check my profile for my email add and I’ll email it to you.
    She wouldn’t quote me over the phone/email but has invited me to their offices, so I’ll go on Wednesday and have a chat (on my way to Laoshan Olympic MTB course) and I’ll see how much they are there.

    druidh
    Free Member

    That gentleman in Holland. Is it Marije Voskuijl?

    Travis
    Full Member

    all I know is that it’s a jw@something (don’t want to break to forum rules)

    druidh
    Free Member

    Ah – OK. Just thought it might have been the Van Nicholas guys as they are based in Holland.

    trent900
    Free Member

    This is great…I sign up for the singletrack forum and this is the first topic I stumble across! I am metallurgist you see (well, a Materials Scientist technically, but more metals than anything else) and I have a special interest in titanium alloys.

    I can’t see why Chinese Ti would be any better or worse than American or Russian Ti. The technology to cast and work Ti is pretty standard. What will make more of a difference is what specification the Ti is released to. If the American supplier is making to spec A and the Chinese to spec B then yes they will be different but if not, they’re likely to be indistinguishable.

    There was a comment above about Russian and Chinese Ti being worse because they have ‘re-used material’ in. This is called revert and everybody does it. Most of the titanium available on the world market includes revert. Ti would be stupidly expensive if people didn’t. If On-One aren’t using revert then they’re mad.

    Any difference between the USA supplier and the Chinese will come in the welding and heat treatment, which are moderately complex. However, it’s not so much about nationality – there are some appalling American suppliers, believe me, and excellent Chinese ones, and vice versa. It’s about trained welders and decent vacuum ovens, which are very gettable in either country. If the welding is accredited and the welds are x-rayed and crack tested then I’d be just as happy on a Chinese bike as an American one.

    The disappointing thing to me is that we have to use Grade 9 Ti, also called ‘half 6/4’. It’s easy to make into tube but it’s pathetically weak. With a bit more effort I reckon a Grade 5 frame is possible which is much stronger and therefore lighter…

    Sorry about the essay post, you can tell I enjoy my job working with these alloys (and Aluminium! I understand Al too if anyone wants to start a thread about that!)

    Cheers,

    Jon

    trent900
    Free Member

    Although to be fair if they’re trying not to make it TOO flexy then maybe thinner tubing is not desirable so why bother having a stronger alloy, in which case fair enough.

    Jon

    Nicknoxx
    Free Member

    I’ve posted this previously but it seemsrelevant to re-post it here:-
    According to Mark Lynskey Ti is Ti:-

    “As to the raw materials; did you know that everybody’s starter materials (tube hollows) come from either Russia or China. Yes that includes Sandvick, Haynes, Wolverine, and Reynolds. Yes the tubes that these companies create using Chinese and Russian raw materials do in fact go to aerospace/defense use as well as bicycle frames (including ours). “

    Read the whole comment here.

    http://weightweenies.starbike.com/forum/viewtopic.php?t=49167

    scaredypants
    Full Member

    jw@….. sounds a lot like the Van Nich guy (or more specifically, the airborne guy who sorted me out a few yrs ago)

    Travis
    Full Member

    apparently it IS the Van Nich guy (someone has emailed them, and let me know the reply)

    silverpigeon
    Free Member

    This is great…I sign up for the singletrack forum and this is the first topic I stumble across! I am metallurgist you see (well, a Materials Scientist technically, but more metals than anything else) and I have a special interest in titanium alloys.

    Welcome to STW Jon.

    You are just what this forum needs. Somebody who actually does know what they are talking about

    Joxster
    Free Member

    silverpigeon – Member

    This is great…I sign up for the singletrack forum and this is the first topic I stumble across! I am metallurgist you see (well, a Materials Scientist technically, but more metals than anything else) and I have a special interest in titanium alloys.

    Welcome to STW Jon.

    You are just what this forum needs. Somebody who actually does know what they are talking about

    We don’t want their type round here 😉

    Rockhopper
    Free Member

    Didn’t Specialized stop making their S Works frames in the US (in about 2001 i think) becasue Taiwan and the far east could producde better welds than the Yanks could?

    sq225917
    Free Member

    The best Ti welds I’ve ever seen on a bike have been on Moots frames, no two ways about it.

    paulosoxo
    Free Member

    You haven’t seen my welding 🙂

    compositepro
    Free Member

    you can get 6-4 ti tubing still (despite the rumours of its demise)

    its not seamed welded tubing either

    im assuming trent 900 you have something to do with that little firm that makes wirly round air suck through things down moor lane in derby

    best welds i ever saw were on the trent 500 COC

    the_lecht_rocks
    Full Member

    what’s a trent 500 COC ?

    cynic-al
    Free Member

    isn’t pointing at welds and saying “ooh those are smooth” just another form of tyre-kicking?

    MrSmith
    Free Member

    what’s a trent 500 COC ?

    it’s a jet engine isn’t it?

    Kahurangi
    Full Member

    isn’t pointing at welds and saying “ooh those are smooth” just another form of tyre-kicking?

    Certainly not. I’ll have you know that modern fingers are capable of electromagnetic and ultrasonic NDT.

    However visual inspection is sometimes enough to spot horrific welding.

    thekingisdead
    Free Member

    what’s a trent 500 COC ?

    Im gonna guess and say a combustor outer casing. In which case its most probably a Inco718 or C263 EBW weld. Harder to weld than Titanium!

    thekingisdead
    Free Member

    All this talk of “quality welds” is nonsense. What you mean is how “pretty” the welding is. I see horrible looking welds pass aerospace acceptance standards / crack test etc, and i see “pretty” welds fail specs / crack test etc. Dont think a pretty weld always = a good weld.

    Does anyone know if Titanium frames have the welds x-rayed? Seems a bit OTT for me.

    Travis
    Full Member

    popped into the local shop this morning, and whilst browsing came across this;

    It has 2 screw like thingies, so that the frame can be taken apart and placed into a suitcase. This particular bike had 700c wheels, V brakes and was made up like a tourer. Quite nice really.

    The screw thingies are made in the USA and then imported into China.

    richc
    Free Member

    so then, could anyone tell the difference between the Lynsky and Airborne 456?

    Stoner
    Free Member
    hora
    Free Member

    isn’t pointing at welds and saying “ooh those are smooth” just another form of tyre-kicking?

    funnily, people agonise/drool over that then throw their treasure down a trail that kicks up stones/grit etc as well. Madness.

    wwaswas
    Full Member

    I always get off and walk on anything ‘down’ for that very reason.

    UpQuickDownSlow
    Full Member

    Does anyone know if Titanium frames have the welds x-rayed? Seems a bit OTT for me.

    I think it is unlikely that any frame manufacturers do this. It would get added to the marketing blurb.

    hora
    Free Member

    How do you know its chinese/Russian or US? Say a small boutique maker buys (unseen) through a factory who makes it for them? No way of knowing unless you listen intently in silence to see if it starts talking chinese/gibberish to you? 😆

    trent900
    Free Member

    what’s a trent 500 COC ?

    It is a combustor outer for the Trent 500 engine, yes! C263 I think – not something I’m well versed in…nickel alloys…ugh. Heavy things. I work at the cold end of engines, on titanium, aluminium and magnesium alloys, some steel, and composites. Also known as bike frame materials! How handy.

    I’m glad there’s lots of people here who know that a weld that looks pretty is not necessarily a good weld. You can have a sexy looking weld with half a tungsten electrode in it. Oops.

    Someone up-thread confirmed the availability of 6/4 extruded tube. I thought you could get it! It would be great stuff for strength-limited design (not as good as 15/3 though) but I think frames are stiffness-limited.

    Someone else asked if frame welds were X-rayed – I have no idea. They wouldn’t be easy to X-ray properly, I suppose, but if you could do it on thin tube it would be a sensitive technique. If it’s at all possible it would be a good idea on hand-TIGed tube, that’s all I’m saying. I’m think these are 6G welds (the hardest possible!), so I’d want mine inspected to death 😀

    trent900
    Free Member

    How do you know its chinese/Russian or US? Say a small boutique maker buys (unseen) through a factory who makes it for them? No way of knowing unless you listen intently in silence to see if it starts talking chinese/gibberish to you?

    That’s one way. You could ask your supplier for the material release certificate, but listening to the frame in silence is probably easier.

    Sanny
    Free Member

    Given the choice between the two sources of Ti, I wouldn’t care where the tubes are sourced to be perfectly honest. What really matters is how the frame is designed and who builds it. I don’t subscribe to the notion the US builders are inherently better by dint of nationality nor by **** marketing hype. I ride an Ibis Silk Ti, a Hummer and my missus has an Airborne crosser. To be honest, you’d be very hard pushed to tell the difference between the three despite coming from different factories. I love the dinky head tube badges on Indy Fabs but it’s not enough to justify paying almost three times the price of a Van Nicholas.

    So big up the far east – cheaper, ride just as well and safe in the knowledge that you can spend the money you save on more riding holidays!!!!! 😀

    Cheers

    Sanny

    DoctorRad
    Free Member

    All this US / Chinese discussion just sounds like FUD (Fear, Uncertainty, Doubt) marketing to me. is there really any hard evidence that there more failures on either side in relation to the number of frames in circulation? And what proportion of frames on either side actually fail prematurely (for some value of 'mature')?

Viewing 33 posts - 81 through 113 (of 113 total)

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