ElRey.....

Frame Geometry IS the same as fork rake, head angle and trail. They are the DETERMINING FACTORS of the frame geometry and how the bike will handle. The combination of head angle and fork rake have more effect on the bike's steering than any other factors. Fore-aft weight distribution, center of gravity and wheelbase will also determine how a bike handles, but to a lesser extent than the front end geometry. After all, it is the fork that does the steering.

We are talking about tandems here, not racing singles or TT singles. If you look at any tandem manufacturer's website and look at the frame specs, you will find that with few exceptions, the frame geometry is identical within the models/price ranges for each give frame size. The seat tube angles are the same, the wheelbase is the same, the fork rake (offset) is the same. Burley offers an upgrade to a carbon fork with less rake but otherwise, everything is the same across the line.