Tough to say. Maybe bring it to a couple more shops, and get a few opinions?
I got a similar dent in one of my bikes recently, more of a straight crease than the round crater you've got. I decided not to ride it even though some guys I trust said it was probably fine. I just didn't trust it.
Colnago Altain, Klein Pulse II, Stumpjumper FSR, GT Zaskar LE, Pedalforce RS2
I agree with Bostontrevor. My friend's scandium MTB Frame had a similar dent in the same area. He talked to the framebuilder who, upon inspection, advised him to replace the frameset.
I think of it like an aluminum can. An AL can will support my weight if its shape and integrity is still cylindrical. However, if I place a small dent in the side and then try once again to balance atop of it, it will collapse instantanously.
thanks for your replies.
I think I'll get a new frame. It was a cheapo anyway. But the next will be at least 1500 g. I think. I am a bit surprised how light it was to damage it, I am not even sure how it happened. I think it was a small stone somewhere.
Now I am tempted by Ti if my dentist does not bankrupt me, but that's another story.