Picked this up yesterday for the components, and looking for thoughts on what killed the headtube. Two cracks at the bottom and one at the top. No discernable damage to the fork blades or steerer (the headset cups and bearings are not installed in the photo, so the fork angle may look off but it would look fine if all the parts were installed).The extra long stem was mounted to the no more than the depth shown when I got it, since that's as deep as it will go. I'm thinking that forces related to the long stem was probably the cause. I considered improper headset cup installation but thought that the probability of cracking both the top and bottom due to that would not be that great. The frameset is a 1996 KHS Aero Turbo. it's a very nice/light frame in very good condition otherwise. Thoughts on likely cause(s) of the cracks?

I think you're correct in that the locations of the cracks, both top and bottom in a fairly concentrated area, look to be the result of the forces imposes by the overly-exposed stem. In that case, Negligent Homicide should be the charge

DD

Steel is real?

Maybe homicide by driving a 42mm cup into a 41mm ID bore?

My brother cracked a frame like that after the old "roofrack-garage" thingy.

I'll posit that a garage door came down just right on the handlebars and/or stem and triggered the safety to retract the door. The initial weight and jolt on just the cockpit might have done it.

Were I the detective, I would begin my investigation on the hypothesis that somebody drove into their garage with the bike on the roof rack.

--Shannon

PS: The easy way to ensure that this never happens is to take your garage door opener off of your sun visor and put it in your seatbag. Or even your glove box... if you have to look for it, you'll almost certainly remember why it wasn't in it's usual place.