Originally Posted by DaveSSS

I'm a mechanical engineer. JB Weld epoxy has a tensile strength of over 5000 psi and great bond strength. I first made this type of modification over 10 years ago. I just sold the frame with that mod this week. It works perfectly. I also built up two new Colnago frames recently and made the same mod to them. I've even used this product to extend the length of a steering tube by up to 15mm. https://www.jbweld.com/product/j-b-w...fessional-size

The question about this oval tube is what the maximum diameter is - 1-1/8" of something larger? Getting threads centered in the long direction might be a bit tricky.