# Cheap Chinese Titanium Tandems?



## dynamic_e

Our aluminum frame has a crack on one of the welds and it's time to consider a new frame. Most tandem frames new go for more then I can get a complete tandem off craigslist, but I did come across these frames that are priced very attractively. Anyone try these yet?

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## CliffordK

You may be able to get your frame repaired, although at full shop costs, plus painting, it could get expensive fast. 

The Chinese frames you found look very nice. 

Titanium has a reputation for being a bit flexible, which may be good, but I'd worry about it on a Tandem.

What about this triple tube design for a little extra support? They claim it is only 2.2 kilos.

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Anyway, the price looks reasonable, assuming you can get the options you wish for, and can either transfer components from your existing frame, or otherwise do the build.


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## pmf

Interesting site. I search for road racing bikes and got a large choice at really low prices. A Colnago C59 frame/fork/post for $600. They have all kinds of paint choices as well. Is the market for knock-offs this big?

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## CliffordK

Alibaba and Alibaba Express are great sites for buying stuff like batteries that one expects to be made or sold in China Hong Kong, and Taiwan. You have to watch shipping costs though. 

The OP wasn't asking for a forgery, just a nice Titanium frame, which is what one would expect.

As far as the Colnago C59. Obviously they are a made-in-Italy frame, so an Asian frame is very questionable. From the images, that is an extremely good copy. It is kind of like playing "What's the Difference" games as a kid. 

The biggest external differences seem that some of the Colnago frames have an extra band around the seat stays just above the rear dropouts that doesn't show up on the Chinese Knockoff. And, the hyphen in Q[SUP]2[/SUP]-Stay is different.

The Chinese rear derailleur hanger and rear cable stop are also in non-matching colors whereas the Colnago frames have them in matching colors.

No doubt there would be other differences apparent in the finish, RIDE and perhaps weight if one had two frames/bikes to compare.


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## pmf

I wasn't insinuating that the OP was asking about forged bikes -- Just found it interesting that there are so many to choose from on that website. It wasn't just Colnago -- they had Willier, Look, Cipollini, etc.


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## dynamic_e

Knockoff market is very big in Asia. Many brands manufacturer in asia as well and sometimes the factory gets greedy and sells product on the grey market.

Anyhow, I am not a fan of knockoffs. I would rather get a used genuine frame then a knockoff. I guess the titanium tandem market is very small.


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## nsfbr

I, personally, would stay away from Chinese Titanium unless I had personal knowledge of the source and certification program. The best Titanium alloys cost more and are more difficult to work with than the cheaper, weaker ones. 6Al4V is the standard, but it has started to be supplanted by companies willing to do the engineering to design in lower performing, but easier to work with alloys. And that is fine when you have a company making designs work for the material. The problem comes when someone "copies" a design but uses a lessor material. Then it is bad news. 

That's not to say that you won't get a wonderful deal on a great frame, but I personally would not do it given experience I have had in the past (which very admittedly is ~10 years old and not in the bike world.)


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## CliffordK

nsfbr said:


> The best Titanium alloys cost more and are more difficult to work with than the cheaper, weaker ones. 6Al4V is the standard, but it has started to be supplanted by companies willing to do the engineering to design in lower performing, but easier to work with alloys.


3Al2.5V is the most common titanium tubing. I'm not sure anybody is actually currently mass producing 6Al4V for bicycle frames, although some NOS Reynolds tube sets still show up from time to time.

The welds may be better with the 3Al2.5V, and less prone to cracking. As far as I can tell, the frames may be a little less stiff, but the difference is minimal. 

A Tandem may benefit from all the extra stiffness it can get (thus earlier I suggested frames with more diagonals). However, I wouldn't be overly concerned with 6Al4V vs 3Al2.5V.

I doubt they're using other alloys, but it wouldn't hurt to ask.

As far as the quality of workmanship of Chinese products, it can be all over the board, and hard to judge from a stock photo. The companies on Alibaba seem to be fairly high production shops so they should have experience with the material.


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