Every version seems to be heavier than the one it replaces... and not just at Bigfoot
(but especially with them)
Some contributing factors:
- increased body width
- additional standard features
- thicker body construction (e.g. thicker foam in 2500 series versus 1500 series)
- additional body structure (at some point they gained a plywood roof panel), in some cases to accommodate a more squared shape
As the trailer body gets heavier and perhaps the maker allows for more cargo, the frame might get heavier to be strong enough. Certainly the axle
capacities have gone up with time, so the axles (and wheels and tires) themselves are heavier.
By the way, I doubt any of those 1980's units really weigh as little as 1875 lb (although I could be wrong). That number is probably with no optional equipment (and just about every trailer has options), and even propane
tanks and batteries were at one time considered "options". Another factor might be increasing honesty by the manufacturer - the numbers could go up without the trailers actually getting heavier!