My S7 SS with 912 ULS, Whirlwind 3-blade prop, 22" tires & T3 tail spring, and covered with Oratex weighs 819# empty. Gross weight is 1550#. So 731# useful load. As an example, I can have 175# in the pilots seat (me), a 200# passenger, full fuel (27 gal.), and 100# in the cargo bay (structurally designed for 150# max.), and my CG is at 15.31". The aft limit is 16.00". I don't particularly like the "feel" & performance under those conditions, but it's able and safe.