Originally Posted by
Kimmo
Depends. Carbon doesn't have great impact resistance, but ally isn't great in that respect either, at least on light frames. Carbon is otherwise incredibly strong and resilient, and a crash that would turn a metal frame into a crumpled mess can leave a carbon one unharmed if the frame doesn't suffer a direct impact. Then there's the fact it's the most easily repaired material, while ally just isn't practical to repair due to heat treatment.
I scored a 330g Time fork for $0, because one dropout was twisted. The bike it was on had been violently removed from a roof rack. The dropout was ally, so it wasn't shattered and I was able to bend it back, but the rest of the fork simply wouldn't have survived if it was anything but carbon.
Big believer in the strength of CF and not worried a bit about the reliability of a CF fork-- even so, it is interesting and perhaps a bow to reality that Trek went with an aluminum fork for it's '19 520 tour bike. No doubt CF could be used to make a fork that also can carry the weight of loaded paniers but... I guess it'd be too expensive for relatively inexpensive steel road bike.