Originally Posted by
Bob Dopolina
That's a good point about the cable stops but the effect those stops have on the structural integrity of the frame should be very small. No data on this just spitballing based on failures I've seen in the past.
This looks like tube to tube construction which is why the failure at the junctions doesn't raise an eyebrow.
The fact that the impact happened at 35km and caused such catastrophic failures in multiple place suggests to me that it is a resin issue. Polyester resins are much cheaper and more brittle than resins used in more expensive frames.
Another thing to consider is the fact that the Chinese market is now flooded with locally produced prepreg that is compatible to T300 as opposed to the T-700 that is pretty much a benchmark for contemporary frames. I can't recall the tonnage of T-300 off hand but it is much lower than that of T-700.
All speculation on my part but possible explanations as to why this frame ate it so badly in a crash that shouldn't have ended its existence.
Too small of a data set to come to any conclusions, but if we are going to speculate at least use the available data in the thread and some basic logic. You have two pictures on this thread to compare -- the OP and the CAAD. Some observations: Both were head on collisions. Based upon the ride where the CAAD accident happened both were at very similar speeds. One was carbon into a motorcycle. One was aluminum into another rider. Aluminum doesn't use resin.
Now look at and compare the stress and breaking points in the two pictures.
Carbon Frame: Break in the TT about four to six inches from the head tube.
CAAD: Break in the TT about four to six inches from the head tube.
Carbon Frame: Break in the TT about four to six inches from the seat tube.
CAAD:Break in the TT at the seat tube.
Carbon Frame: Break in the DT where it connects to head tube.
CAAD: Bend, but no break, in the DT about three to four inches from the head tube.
Carbon Frame: Break in the DT where it connects to BB.
CAAD: Break in the DT where it connects to the BB.
There seems to be a problem in this thread distinguishing between correlation and causation. An unbranded frame broke to pieces in a crash in no way equates to it broke to pieces
because it was an unbranded frame. In fact if that was some sort of hypothesis that was being tested the evidence in this thread that is most comparable, the CAAD picture, directly contradicts that idea. Think of how ridiculous it would be to suggest a CAAD frame broke to pieces in a crash, therefore it broke to pieces because it was a CAAD.
"All speculation on my part but possible explanations as to why this frame ate it so badly in a crash
that shouldn't have ended its existence." (my emphasis). Why shouldn't it have ended its existence? That assumption seems not only baseless but in direct contradiction to all of the other pictures in this thread. The starting point should be the cause of the "asplosion" was direct force applied to the front of the bicycle in an amount and at angles the frame wasn't designed to handle and that most frames, even CAAD frames, are not designed to handle.