changes in hitch weight in the '70s

[transy416]

I've been spending some time looking at the trailer specs pages of 70's 31 foot models on Airstream's website. The hitch weights range from 545 lbs to 730 lbs across the years, being lighter in 1978 and 1979. I've been looking at center bath models and the floorplans look relatively the same over the years. Did the weight of the materials vary that much?

1973 695 lbs and 730 (twin bed, double bed w/center bath)
1974 650 and 690
1975 650 and 690
1976 650 and 690
1977 710 and 715
1978 545 and 545
1979 545 and 545

[87MH]

My '78 Sovereign, loaded for camping, weighs in with 860 lbs on the tongue, 3180 on the front axle, 3280 on the rear, sitting level on a scale (this is with the Hensley Hitch mounted on the tongue, dangling in the air).

[transy416]

Yeah, I imagine the "real" weights vary quite a bit as you have pointed out. Do you now though why the unloaded weights vary so much over the years, particularly with a 78 or 79 compared to a 76 or 77? Did the thickness of the frames change?

[Lumatic]

Originally Posted by transy416

I've been spending some time looking at the trailer specs pages of 70's 31 foot models on Airstream's website. The hitch weights range from 545 lbs to 730 lbs across the years, being lighter in 1978 and 1979. I've been looking at center bath models and the floorplans look relatively the same over the years. Did the weight of the materials vary that much?

1973 695 lbs and 730 (twin bed, double bed w/center bath)
1974 650 and 690
1975 650 and 690
1976 650 and 690
1977 710 and 715
1978 545 and 545
1979 545 and 545

FYI
My specs show tongue weights for 31 footers you don't list

1973 shows
rear bath twin 485
rear bath double 490
1974, 1975, 1976
also 490 and 495
1977
also 620 and 630
1978
also 555 and 580
1979
also 555

[transy416]

Yeah, I was just listing weights for models with a center bath. Either way, why do you think there is so much variance throughout the years?

Originally Posted by Lumatic

FYI
My specs show tongue weights for 31 footers you don't list

1973 shows
rear bath twin 485
rear bath double 490
1974, 1975, 1976
also 490 and 495
1977
also 620 and 630
1978
also 555 and 580
1979
also 555

[transy416]

Anyone have an answer? Would the changes in weight be strictly due to the materials used for the furniture, or something different about the frame/exterior?

Would there be a better forum for this question?