Originally Posted by
oneclick
The BB shells had a (deserved) reputation for cracking, especially (mostly?) the MTB ones.
I saw one on a boot sale table once and that was the reason it was there.
yep, brittle.
the Porsche 917 had much magnesium and it was not publicized. Mark Donahue answered a Road & Track journalist that the Porsche CanAm chassis was made of unobtanium.