Possible prevention of head tube blowout on Kinesis aluminum

[mixalive]

It appears a lot of folks with the (made for Barracuda) Kinesis aluminum frames are beginning to show signs of fatigue in the form of cracks. These cracks are showing up at the top and bottom of the head tube and the seat tube. This article deals with a possible prevention of head tube fatigue.
My idea was to machine a ring that could be pressed over the top and bottom of the tube providing support in the blowout areas. I decided to use chrome moly steel for my rings. I ordered a 1 ft section of cromo tubing from Aircraft Spruce, and had rings machined thin enough so when pressed on the head tube, they would not conflict with the intersecting tube welds. I was charged just over an hour for labor for the machine work.
To prep the frame, I wrapped masking tape around the tube where I thought the ring would butt up to, and used a mild paint remover to strip the tube down to metal.

[mixalive]

After measuring the head tube, I realized it was not perfectly round due to distortions when the frame was originally welded. So I decided to fit the ring to the tube instead of having the inside diameter of the rings machined to fit. I used a sanding drum chucked up in my drill press set to the slowest setting of about 400rpm and worked it down to about a 0.1mm smaller than the tube diameter.

[mixalive]

I then taped off the head tube and applied red Loctite to the tube and ring.
At 0.1mm, the ring pressed on fairly easily. I didn’t want it to be too tight as to stress out the head tube.

[mixalive]

After letting it cure over night, I primed and painted the rings.

[mixalive]

Now, if your frame is already cracked in these areas, it would have to be your call if welding up the cracks and adding rings would be safe. I felt confident on my bike as I did not have any cracks yet.
Understand: Aluminum has a finite life and it is just a matter of time until it will begin to fatigue.

[cudarider1]

Again I'm super impressed Mix! Great job and glad you could use that pic of my broked cuda.

[Mark]

Wow.. Truly great write-up!

[ctk]

Superb- and that XX is sweet!

[neo_pop_71]

Brother Mix is the Zen master of Cuda repairs...

"Snatch the pebble grasshopper, only then will you be ready..."

[mixalive]

I have a bunch of those machined rings laying around. I would weld up and ring that cudarider frame in a heartbeat.