mred33

Any plane has a CG that it likes and may in part be due to your flying style. The quick and dirty methed of 25% to 33% holds true for a starting point on any plane be it single wing or bi-plane. On a bi-plane you treat both wings as one and go from the LE of the top at center to the bottom TE and figure 25% to 33% and mark your CG. After you fly it, you may want to move it forward or back depending on where it is and your feel of the plane. I uasually start at 25% and go from there. That is a safe place to start and will not give you a touchy plane in pitch. Starting at 25% is safe and gives you a chance to see how it flies and you can adjust it after flying it to you likes. You can go through the math and still wind up having to change the CG on most planes because there are to many things envolved in determining the GC to say it is always going to be this point. It won't. It will be where the plane likes to fly and you are at ease with. It depends to much on to many thing to say it will always be this point and never change. It will change from one plane to the next even if they are the same kind. With a two wing plane it is going to look further back on the top wing then you will see on a single wing, but that is because of the bottom wing. Start with 25% and you will have a plane that is easy to fly, but probably a little nose heavy. Safer then tail heavy and not as hard to control.
Have fun with the new bi-plane, they are loads of fun.
Ed