The Delta site contains
conflicting information about the weight of the ski bag (emphasis mine):
The combined weight of both items (ski/snowboard bag and the boot bag) may not exceed the standard baggage allowance specific to the cabin or excess weight charges will apply.
and
If the combined weight of ski/snowboard bags and boot bag weighs over 50 lbs, the applicable excess weight fee will be charged
I gather from the most recent posts that the first one is correct? (I.e. in first class you get 70lbs? Also: they need better copy writers!)