<<my lay analysis of the landing gear structure requires the forward roll bar to reinforce the fuse and negate the inward pressure force of the landing gear during landing on the 8 TailDragger.>>
Interesting point, so I spent a few minutes looking. As it happens, I'm sending an order today for both RV8 and Showplanes kits.
I have a different conclusion. The roll bar is quite far rearward from the gear towers, which would limit its value as a gear box brace. In addition, an open hoop may be quite strong, but it is not stiff. In other words, a hoop is a very poor brace; it allows a lot of flex in the braced structure.
I think the primary brace between the tops of the gear towers is found in the rear baggage crossmember identified as A below. Note the reinforced tie-in at B. Later in the assembly process this crossmember is riveted to the rear baggage bulkhead, which stiffens it against compressive buckling in the vertical plane. The addition of the baggage floor, riveted or screwed, stiffnens it against buckling in the fore and aft plane. In short, it becomes a very stiff tension/compression brace.
It appears that the Showplanes mod adds another crossbrace on the aft side of the gear towers (lower photo).
There is something in the lower photo that I think to be a dumb move. A lot of builders cut away a section of the baggage bulkhead crossmember in order to clear radios and other deep panel items. Not good, for the above reasons.
I do thank you for your comment and I will study the matter more closely when I have actual parts in hand.
Photo credits to Randy Lervold and Showplanes.
Dan Horton
