Kona Track Two fork - at last!

[rody]

Hmm, I'm no physics engineer but I'm a reputable and certified TI welder and I would NOT use a scabbed together steerer :roll:

But then again, maybe I'm just fluffed in the head.

rody

 

[tangent]

ti welding

Sorry bit of a digression here , although ti related

Rody, with your welding experience... a question for you possibly?

I've got a ti frame on which a weld on the driveside of the chainstay had cracked pretty much all the way round - but am reluctent to get it repaired because have little faith left in the weld on the non driveside not developing a similar crack...is it possible to reinforce / reweld something that hasn't broken yet -or is that just plain daft?

 

[Rich]

I too thought the track 2's were recalled after a problem with them...was that all sorted out?...they look well sweet!

Rich

 

[adamgent]

They were all recalled. There was a problem with the legs becoming loose in the crown. I am sure this only affected the Mk1 or Mk2 and not both but cannot remember which. This is why they are so hard to come by.

Ride or not to ride? That is the question? Probably build as a garage queen!

 

[stevet1]

Rody - Interesting to hear that from someone who is actually qualified to make a judgement! JOOI why wouldn't you ride 'em? I would think there would be a lot more stress on the crown/steerer weld than halfway up the steerer but I have no expertise whatsoever :?

 

[rody]

steve and tangent, here's the rub with TI,

to weld TI you must be meticulously clean, have strict attention to preventing weld puddle contamination, and MUST purge both the inside and outside of the tube to create an inert (read oxygen free) weld zone. Anything less than perfection is sure to result in fractures at the point of contamination due to the molecular structue becoming brittle and less ductile.

Common errors in welding TI include imperfect pre-cleaning, tungsten contamination, moving too fast (outrunning shield gas), improper torch angle (gas not shielding area appropriately), and lack of inert gas due to improper purging.

Sooo, given this info...

I would not reweld the chainstay as it would be impossible to clean the interior of the tube sufficiently and purging would also be an issue. If you would try, with much riding, the weld zone would likely fracture again. As for the other side...the tensile strength and ductility of TI is awesome when joined correctly, unforgiving when not. Hard riding will seldom cause a failure (could...) but more likely if one side failed, it is likely the other will as well.

Steve, these concepts also illustrate why riding a copped steerer tube is NOT a good idea. Even with a lap butt, too much probability is present in inability to prepare the tubing and shield the lap during welding to meet my expectations of a strong joint. I'm not going to send someone out on my work unless I'm confident they'll bust their ass before my fork .

Hope this helps...

rody

 

[jez-4-bikes-max]

You are awesome Rody. Brilliant stuff.

 

[stevet1]

Great reply thanks Rody.

 

[cchris2lou]

A true pro .

 

[adamgent]

Ti Weilding

Can't really argue with that. I'm convinced!