Sick Bike Parts Saved My LIFE!

[Happy Valley]

Here are the pictures. The frameset is upside down.

Steel, huh?

I just showed those pics to my bud who is a custom frame maker.
He shrugged and said he'd never seen anything like that, of course he's not into MBs. About his only comment was extreme fatigue on what he guessed is probably the thinned mid-section of double butted 4130 chromoly.
He also asked and hard to tell exactly from the pic but is there any corrosion showing up there where it was wrapped?

Double or triple butted tube sounds good and it is for stress relief in tube joins and welds on a standard bicycle frame though by nature the tube thins in the mid section for weight reduction.

 

[duivendyk]

I've been calling attention to these metal fatigue induced potential frame failures for quite some time now.The microscopic cracks are invisible until the structures is weakened sufficiently to start bending,it then typically fails catastrophically,when subjected to sudden extra stress.Thin wall aluminum frames are esp vulnerable.If it doesn't feel right (steering) take action!!.