I now know what the creaking noise was....

[uphillbothways]

I'm sure I remember reading somewhere that legally "Made in ..." refers to the country of the last manufacturing process, so the frame in my made up example would be legally "Made in Britain" whereas what is of real interest is the welding.

The situation is remarkably complex, bordering on philosophical. The universally accepted principle is that an item is considered to be "made" in the country where it last undergoes "substantial transformation". Most of the rules of origin are very specific, so the leeway really rests on the exact meaning of those two words. A great deal of very expensive legal counsel has gone into substantially transforming what "substantial" and "transformation" might mean.

Under EU rules, painting and finishing don't generally constitute "substantial transformation" on purely or primarily functional objects, although I'm sure plenty of companies blag it. The situation is decidedly less clear if other operations are performed, like facing or threading parts of the frame, adding braze-ons or even attaching a mech hanger. As I understand it, there is no legal precedent establishing when exactly a pile of tubes becomes a bicycle frame. One particularly worrying example of the opposite sort of deception is surgical instruments, where steel scalpel blanks are forged in Germany, shaped and sharpened in Pakistan, but labelled "made in Germany" because the Pakistani manufacturers do not consider their input to constitute a substantial transformation.

Country of origin labelling matters a great deal in global trade because of the imposition of tariffs. A good example is the "chicken tax", a 25% tariff imposed by the US, on imports various goods, imposed in retribution for the taxation of American chicken imports by France and Germany. That created the absurd situation where minibuses (not subject to the tariff) are imported into the US, then have their rear seats and windows removed, turning them into vans (which are taxable).

[Bledlow]

Enigma started off as Omega, IIRC, headed by a frame builder called Mark Reilly. He ran into all sorts of business problems, with it all getting very sketchy until the former owner of a cycle parts distribution company took it over.

But I'm almost certain that the Ti frames were either Russian or far eastern.

The Omega frames were made in Russia. Mark Reilly told me that Burls uses the same Russian frame builder. Expertise acquired in aerospace, supposedly. Again, Justin Burls is completely open about where his frames are made.

The Enigma frames were made in Taiwan to start with. I don't know why there are references to obfuscation. Jim Walker was completely open about it to me (just another customer, nobody special), & they had frame boxes stacked around conspicuously labelled 'Made in Taiwan" when I visited. BTW, Sabbath told me that they'd looked at using the same Taiwanese factory.

That was in late 2008. I heard from Jim Walker in 2009 that custom Ti work was being moved to the UK soon (he'd previously said that the Taiwanese didn't like doing anything non-standard), & the rest eventually. He said the biggest problem was the shortage of appropriately skilled people. I didn't know until I followed the link upthread that Enigma had switched all its Ti framebuilding here. Jim Walker's son Joe is trained to weld Ti, & I read that he was building frames in 2009 (soon after my conversation with Jim), but then it was custom builds only, with the plan to keep buying in OTP frames from Taiwan for up to two years.

http://roadcyclinguk.com/news/gear-news/enigma-factory-visit.html

There y'go. No secrets, no obfuscation that I've seen, just a question of taking the word of the people involved.

BTW, Enigma is holding an open day on May 4th - including demonstration of Ti welding by Joe Walker -
http://www.enigmabikes.com/open-day.html

It'd be interesting to hear the opinions of anyone who knows Ti welding about the demo, or about the TIG welding set up. I've seen a picture of a frame in the open, with holes closed & tubes feeding pressurised argon into it. After what I've read, I'd prefer to see welding with no oxygen around at all.

[Trull]

As a lapsed Incorporated Welding and Joining Engineer... I'd like to point the curious at the foremost welding establishment, check out this page for some interesting info, and a most informative downloadable pdf.

http://www.twi.co.uk/technical-knowledge/faqs/process-faqs/faq-how-difficult-is-it-to-braze-titanium-to-steel/

[Veloman]

As a lapsed Incorporated Welding and Joining Engineer... I'd like to point the curious at the foremost welding establishment, check out this page for some interesting info, and a most informative downloadable pdf.

http://www.twi.co.uk/technical-knowledge/faqs/process-faqs/faq-how-difficult-is-it-to-braze-titanium-to-steel/

Are we not considering welding Ti/Ti or Ti alloy/Ti alloy?  If so, what role does brazing Ti to steel have in the cycle industry?  Answer = None.

Might as well consider superplastic forming and diffusion bonding of tubes for cycles.

Unless you are suggesting a reason why you can't make Ti frames like you make steel frames, and if that's the case then apologies!

Welding Ti is not easy and made more complicated by allotropic alloys such as Ti-6Al-4V that change structure on cooling (or heating) which often required homogenisation heat treatment to ensure uniformity of structure after the welding process and I don't believe that happened with bike frames due to cost for a number of reasons.  So not only did you have a difference in microscopic structure and mechanical properties, you also had the risk of porosity (gas bubble) or inter-metallic particles within the weld due to the challenge of TIG welding and ensuring the argon gas (normal gas used for Ti welding) removed all traces of air (because it could be oxide or nitride particles) to produce a sound weld that was often checked by very high resolution non-destructive testing (x-ray) to look for any porosity or particles.  Now, would this happen to a cycle frame?  I'm not convinced and I'm not surprised that frames crack as there is a desire to go light and saving weight means either reducing tube wall thickness which will increase stress and increase chance of developing/propagating crack, or compensate for this by increasing strength of tube which normally results in more difficult alloy to weld because the microstructure is more complex.

So, make a cycle from relatively easy to weld pure titanium in sufficient thickness to cope with the stress required and you will have a frame that will behave just like those nice lightweight Ti alloy ones (as the modulus of elasticity changes little with alloying) but will last a lifetime.  It will of course be so much heavier than a nice steel one and as a result there will be nil interest. What has made Ti frames viable is the ability to make alloy tubes to make the frame light, but the challenges of welding remain, unless you do it to a specification that makes the item too expensive.

[bikenrrd]

Veloman: very interesting.

Is there a reason Ti frames are not built with lugs (either steel, ti or aluminium alloy)?
I know they were built by glueing the tubes into lugs (e.g. the Raleighs).  Why isn't this technology resurrected and improved on?

[Veloman]

Lugged frames were popular with steel bikes and the fact they could be brazed was really useful!  Although I have a vintage tandem where all the lugs are bolted.  So, first thing is to produce a lug and these were often cast, made of tubes or forged and in great numbers; relatively easy process once the set-up has been established to produce a raw lug that the craftsman could customise.  Braze tubes in place and hey presto, a seemingly homogenous frame, but could be lighter.

So, lets cast some aluminium lugs and glue some aluminium tubes or carbon tubes (early (Alan, Vitus or Look frames) into the lugs.  Easy to cast suitable aluminium alloys into the right shape (or machine from a solid piece of aluminium) and glue tubes in place.  Great bike for mountain climbing as it is light and often used in mountain stages of TDF, but rigid and not so comfortable as steel and not necessarily as rigid as you would want in terms of ‘power whip’ at the rear end.  Then along comes the ability to join and shape the aluminium alloys you want to use so bin the lugs and just weld into tubes; bottom bracket on an aluminium bike is often just a piece of tube with holes cut to accept the tube.  (Titanium frames are the same)  Meanwhile, technology comes along to produce carbon monocoque frames or wrapped carbon lugged frames and we have no need for the glue job into lugs and we have a homogenous frame with no weak joints.

So one reason titanium frames don’t have lugs is the same as most frames don’t have lugs these days; they can build them without the extra weight, and why buy a titanium frame when carbon fibre can produce whatever ride you want (sofa to rigid as hell!).  Many people buy titanium because it will last a lifetime, apparently, and I’m sure many will; mainly corrosion consideration.  Another is that to make a titanium lug, for example by casting, machining or hydroforming, is very difficult and expensive.  Far easier to get some larger tube and drill holes in it or maybe even flare it.  Some titanium frames do not have integrated headsets and the ones that do probably have a tube within a tube arrangement or insert, as the head tube is normally parallel.  There’s a reason for that!

Have a look at:

http://www.google.co.uk/webhp?hl=en&tab=ww#hl=en&gs_rn=11&gs_ri=psy-ab&cp=21&gs_id=2a&xhr=t&q=alan+glued+aluminium&es_nrs=true&pf=p&output=search&sclient=psy-ab&rlz=1R2MDNE_enGB496&oq=alan+glued+aluminium+&gs_l=&pbx=1&bav=on.2,or.r_qf.&bvm=bv.45921128,d.d2k&fp=f92e46dee890ab27&biw=1024&bih=694

and:

http://www.pelotonmagazine.com/Wisdom/content/19/838/Materials-and-Construction-Part-III

for a rather dated article of frames, but still useful.

And of course:

http://en.wikipedia.org/wiki/Bicycle_frame

[Trull]

Veloman: very interesting.

Is there a reason Ti frames are not built with lugs (either steel, ti or aluminium alloy)?
I know they were built by glueing the tubes into lugs (e.g. the Raleighs).  Why isn't this technology resurrected and improved on?

You have to use lugs to join steel as the heat affected zone from welding is harder than the normal steel if you don't bother to fully post weld heat treat it - hence liable to cracking. By using lugs you can braze the metal together at a lower temperature which side steps the issue. With fully modern steels its possible to tig weld and heat treat without these problems but there is an attendant cost. Which is why your Thorn 853 frame is not cheap.
You could build a Ti frame with lugs, but why bother when welding works better and saves the weight? the crunch is in the details of welding Ti - you need good pre heat, excellent welding parameter control, good post weld heat treatment and good non destructive examination to pick out any issues with lack of penetration/inclusions/porosity etc. Going to the lowest bidder for the welding is liable to end in tears!

[alexb]

Welding Ti is not easy and made more complicated by allotropic alloys such as Ti-6Al-4V that change structure on cooling (or heating) which often required homogenisation heat treatment to ensure uniformity of structure after the welding process and I don't believe that happened with bike frames due to cost for a number of reasons. 

Aluminium frames are routinely post-weld heat-treated, so this is actually a standard industry technique and well-established. Of course, some alloys don't require it and some do!

[eck]

Now then, my turn, I think!
I have a 2003 Airborne Zeppelin titanium frame that started to creak the other day under pressure from the LH crank. In hopes that it was the bottom bracket, I removed the crank and was able to tighten the LH cup (Token square taper) just a little.
Good news: that seems to have cured the creak.
Bad news: I also removed the RH crank to check the BB on that side. On close inspection, I spied what looks like a minute crack in the weld at the right-hand side of the BB / seat tube joint, running along the weld and into the seat tube itself. Very like the one pictured in Jurek's pic up there somewhere,  but not as long.
I've already had a different crack, on the LH chainstay - BB weld, repaired about five years ago, and that is still absolutely fine. That was done by Vernon Barker and cost about £50 IIRC.
Does The Panel think it's time to admit defeat with this frame, or do we reckon it's worth another repair?

[mrcharly-YHT]

If a repair costs £50, I think it is worth it.

At least with Ti you don't need to pay for respray

[Jurek]

I'd go with what Mr.C is saying. ^
£50.00 isn't a lot.

[StuAff]

I agree with them. Repair will have gone up in price, whoever does it, but compared to the price of a new frame....