As per Brion Toss
The general rule, as per Brion Toss, of Pt. Townsend WA says the uppers should be about 15-20% of breaking strength, and lowers about 10-12%. If you've got the standard 3/16" uppers and 5/32" lowers that would be about 650-800lbs (uppers) and 280-400lbs (lowers). You'll need 2 different Loos gauges if you've got the 5/32" lowers, because they change gauge sizes at 3/16". If you've got 3/16" all around, as some (like me) have done if re-rigging, then you can back off the lowers somewhat. Check Brion's website.
