With the help of a professional airplane weight and balance mechanic and 20 sand bags, I did my test to see what the actual tail weight is at gross weight in three-point attitude. I had previously overestimated the total weight, but he weight still exceeds that allowed by the Baby Buswheel.
The test plane is a 1975 180J with a few tricks added. I had a weight and balance done a couple of years ago and as it sits with all these tricks it weighs 1876#. In level flight attitude the tail weight is 130#. In three point it's 200#. So, I experience a 53% increase in the three point with no other changes. My gross weight is 3190#. Today I had the plane on certified scales and loaded it with sand bags in a well-distributed load that took it to 3190# and was within legal CG. The tail weighed right at 600#. I could have played with the loading and changed it a bit up and down, but this is a representative weight while in a normal (legal) load distribution. Without question a 3500# 185 would have 700# plus in a similar test.
For estimating purposes I can divide my plane's total gross weight into five parts. Each main carries approximately 2/5 of the weight while the tail carries 1/5. This is not perfect by any means, but it works on my plane.
I wanted to know, so I paid my money and found out. No speculation, no smoke and mirrors, no BS. There it is.
Stewart