Headtube Fixes - Lend me your brains and experience!

Hi all,

So my 96 XXTeam frame (Kinesis 7005 series aluminum) has a small crack at the bottom of the headtube. It's about 8mm in length and starts at the bottom of the headtube, right in the front. Not a great spot for this, I know.

I'm seeking your opinions and experience (if you've repaired something like this). The way I see it, I have these choices:

1. Repair it by removing material and filling it with a weld.
2. Place something tightly around it to prevent it from expanding, like the complete opposite of a shim.
3. Replacing the head tube completely.

Obviously, #3 would be the best option, but does anyone have knowledge or experiencing in doing this with an aluminum bike? I've heard of it being done with steel.

#2 would likely be easiest, but I wouldn't want to use something as cheap as a hose clamp, I'd want something really nice, ideally from aluminum tube, perhaps something like a spacer, if I can find the exact diameter and size I need, and if it can be slipped on nice and tight.

I think I would avoid #1 since it's such a high stress area of the frame, I'd think it would just act up again down the road.

Let's hear your thoughts!

I had one done years ago by a friend.
I got him to drill a small hole at the end of the crack and then run a bead of weld down the crack. Reamed the head tube and cleaned up the weld!

Was yours 7000 series aluminum also? Did it hold up well?

There is a company over here in OZ who do a lot of alu frame repairs

Probably a bit far to come , but you could show this to your local framebuilder/ machinist maybe?

http://www.gripsport.com.au/main.php?pa ... y&galID=16

Andy

Oh snap! That's what I was envisioning in option #2.

Well, what I was going to suggest was that you stop-drill the crack (to prevent further propagation) and then press on a sleeve to ring reinforce it.

Pretty much as above then.....

I would do 1 and 2 with a custom made collar

I have the same problem but on the rear of the headtube, and there is no room for a collar as the downtube meets the headtube near the ends. I was thinking maybe a gusset welded on the top (where it meets the headtube, not actually on the top of it) of the downtube to reinforce. Thoughts?

Someone on here had a gusset welded in the same place but I can't find the thread, not sure it was alloy though!

Have a look on the gripsport website

they have several pages of gusset repairs as well

Andy

Is it really possible to repair an Alu frame? I've always had in my mind that if you take a heat treated frame and then weld it the process of welding screws with the heat treating. To make the metal strong again you need to re-heat treat it. Am I completely out on that???