We have been thinking of changing our power cord to the ultraflex style so it is easier to roll up on chilly mornings.
Then I started thinking as to why is the 10-2 plus ground cable so large for RV connections. Similar high end 10-2 extension cords are 1/2 the cross section, I would guess. Using a very good ultraflexible extension cord cable would allow probably double the lenght in the same storage space.
I have to assume that the RV cables are so big to allow for continuous outside service in areas where they may get run over or such, or on a dock for boats. A class b cord spends most of it's life in storage, just like our 100' of extra extension cord that we carry, does.
Has anyone just put the 30 amp plugs and sockets on the end of a good 10-3 extension cord? You would have to shim out the OD at the connections to fit the plug and socket to cord, but that could be done with a small piece of insulation off the big heavy cord and shrink tubing. Sure would be nice to have 30' cord that fit where our 15' one does now.