Fritzed head tube ??

[Keith B]

I'm forcing crazy glue into the crack as we speak, its not a problem...no need to panic....awwww piss it looks worse in the pics!

[foofighter]

JB WELD! does it all

[DeeZee]

Originally Posted by Keith B

Here we go..........

your old friend and replace it. That thing is an accident waiting to happen

[CalEpic]

It's toast IMO.

You could go through a huge pain in the ass to try and fix it if there is a sentimental attachment, (and worry about it every time you rode it) otherwise I'd clean it up and hang it on the wall over your couch as art.

According to Columbus website, those tubes do need to be heat treated after welding.

C

[sauce]

i think you should make dave hinde give you a new one :-)

[RacinJason]

I bet he can fix it .

Originally Posted by HUGH

Can you post a picture of the cracks? Also if you could find on the frame what kind of aliminum it is that would be a big help.

HUGH

[Keith B]

Another one bites the dust. There'll either be another sell off coming or maybe a steel replacement. Thanks for everyones thoughts & opinions

.........Although I'll PM Hugh to hear his thoughts....

[SAR_boats]

Originally Posted by CalEpic

According to Columbus website, those tubes do need to be heat treated after welding.

C

http://www.columbustubi.com/eng/3_2.htm


The alloy 7000, used by Columbus for the tube sets Metal Altec2 Plus, Zonal and Airplane, is defined as self-tempering: it is air-hardened. This means that in the areas overheated by the welding the supersaturated structure is restored, which, owing to the natural ageing (which takes place at ambient temperature), allows for a 75% recovery of the initial properties after a lapse of time of about 3 weeks.

Columbus does recommend precipitate oven tempering and aging for the tubes however in this case since the tubes developed stress fractures in them air hardening may be the better choice because the finished product may be less brittle.

However, if the original frame was not tempered correctly in the first place then problems like this can also happen. So it is really anyones guess, however getting a machine shop to do all the work to fix the cracks and heat treat the frame and then paint it is going to be pricey

But yes you are right as usual, Craig

[Keith B]

Columbus do some fascinating post heat treating of their alloys - check out the process for their top of the line Starship material! A medium size MTB frame weighs in at 1kg (2.2lbs) superior properties to Scandium too. Now that would be a nice frame to turn SS!

[Pho'dUp]

Bummer Keith but not worth it dude. That's a lot of trouble to fix for no guarantees. I think Sauce likes your smile the way it is.

[RacinJason]

If you cant get your bike fixed I can hook you up.
Thats if you want a Chumba 29er, XCL Or EVO.

Originally Posted by Keith B

I was jsut doing some upgrading to my SS and noticed that there are 2 cracks in the head tube!

Both cracks are about 1/3" long (Forgive me your majesty for using old school units) one from the bottom and one from the top. God knows how long they've been there because the thing is usually filthy!

Is this the end of the line for the frame or is it possible to do a weld inlay and repair if you can someone thats skilled in Aluminium (compensating with the spelling for my earlier non metric faux pas)

I'd be gutted to scrap this frame is its chainstay length means I dont need to run a chain tensioner plus its made from uber light Columbus Zonal tubing. Its only normally used for fireroad and smooth trails but I'm not keen on the fork making a bid for freedom through the headtube incase I take another spill and pick up a further stresss fracture in some of my own metal. Any ideas??

[Keith B]

At the moment its either pick up a Zion for 200notes or sell the parts up to put toward an XC bike to go with my Enduro - but ta for the offer old boy

Originally Posted by ChumbaJason

If you cant get your bike fixed I can hook you up.
Thats if you want a Chumba 29er, XCL Or EVO.

[RacinJason]

XC bike as in bike that weighs less than 26 lbs?
The XCL can handle XC racing with the right build kit.

Originally Posted by Keith B

At the moment its either pick up a Zion for 200notes or sell the parts up to put toward an XC bike to go with my Enduro - but ta for the offer old boy

[Schecky]

Originally Posted by SAR_boats

Columbus Zonal is self tempering 7000 series aluminum, so having to re-heat treat the frame is a non-issue.

You have 2 options:

You can weld in a piece of 1" 7000 Aluminum in the headtube and swap headsets to 1" ( I can hear the groans already)

or

You can have a machine shop cross drill and face the cracks to stop their path, then ream out the headtube 1/10th of an inch then sleeve it with 50/1000 inch 7005 tubing then weld it in place and then fill in the cracks and holes with welding rod

Or get a new frame

Sounds like it may be time to do the humane thing and shoot that horse.

[DeeZee]

Originally Posted by Keith B

Another one bites the dust. There'll either be another sell off coming or maybe a steel replacement. Thanks for everyones thoughts & opinions

.........Although I'll PM Hugh to hear his thoughts....

you said that word..............STEEL BABY!!!

[HUGH]

Have not forgotten about this thread! I weld 7000 series aluminum aircraft parts all the time but they are not strucural in nature. I'm trying to find out the strength of the metal after welding with and without heat treating. If its close it could be done. My advice.... A Ti frame would make a great replacement! A MOOTS would be nice

HUGH

[Hanzo]

This is the second time I have seen this problem with this headset. TC3 on mtbr had the same problem with his headtube cracking but he had an Intense 6.6 and they replaced it. N10sguy aka Marv(Intense mgmt) stated that the OD of the CC headset varied but were on the big side. I know this doesnt help you because you have a euro bike, but it may give you an idea on why. TC3 took down the pictures but it looked very similar to yours.

linky
http://forums.mtbr.com/showthread.ph...cane+creek+6.6

[HUGH]

Checked on this quite a bit. I won't get into the techno mumbo jumbo but I say not to weld it! It will not be safe. Now if it were my own personal frame...

HUGH

[thephat]

Look at on one fames on the bti site. You may like the style. I heard you know somone w/ a connection to a bti account.

BTW I think the crack on the head tube would be enough for me to call the frame a loss.

[Kid A]

Originally Posted by Keith B

Here we go..........

nice...baby got crack. looks to me like "she's dead jim".