Originally Posted by
cyclintom
And the steel bike failures did not appear to be catastrophic - bent downtubes from collisions with cars and the like. I am sure that there have been failures with steel frames that caused crashes and injuries but I haven't seen any and as you say, googling frame failures isn't a good source of information without full knowledge of the circumstances. I have seen pictures of broken chain stays, broken seat tubes at the bottom bracket and I personally had a seat stay break on a Peugeot el-cheapo producto. But all of these steel bike failures allowed careful return to home.
What we can say is that the drive for lighter and ever lighter carbon frames is putting a greater likelihood of catastrophic failure.
Hold on there just a second. First, you are unlikely to find too many pictures of broken steel frames because there are fewer steel frames out there being ridden. The vast majority of bicycles, especially modern ones, are aluminum with carbon coming up fast. There are a few pictures of broken steel frames around
like this one and
this one and
this one to name a few. I doubt any of them were "rideable" afterwards. I also doubt that the failure was slow as well. I've personally broken steel and aluminum frames (two each). The steel frames snapped audibly and were unrideable mostly because the axle snapped as well. Aluminum failed more gently and over a longer time frame. The aluminum bike creaked and groaned for a long time before it failed. I actually rode it for several weeks before I found out what the creaking was from.
Aluminum and carbon don't "shatter like glass" any more than steel does. Steel, being rigid is much more likely to shear suddenly than a soft material like aluminum...which tears...and carbon which is a fabric with alternating layers of fiber running in different directions.