Taken from another thread
Originally Posted by
merlinextraligh
The thing I dislike the most about aluminum is that the extremely thin walled tubes, necessary to make the frame competively light, make the frame susceptible to denting.
My wife's CAAD 8, suffered a fatal dent in the top tube from the bike falling over in the garage.
Same thing can happen to steel when you get down to those .016" tube thicknesses (less than 4 times the thickness of a beer can).
I had a steel frame on a not so light bianchi that folded the down tube hitting a curb at 10mph.
Exposing any frame material to stresses they are not designed to handle can make them fail.