If you guys remember at the initial time of wing builds, I first chose to use 3/32" balsa sheeting to make all the ribs including root ribs but after lil while into the build disregarded balsa root ribs and re-selected lite ply for the root ribs which indeed left wing has, well since i was out of enough ply back then to make both ribs, i had kept one of the 2 balsa ribs aside and after both wing frames were completed night before last night, i didn't really like flexing on the right wing at the root due to being balsa one, so this spare rib came in handy as I set wing on it's root on the building table and epoxied on that spare rib on this wing root as doubler, this also reinforced the root rib and it's strength and slightly extra thickness on the root, doesn't really change the wing's diementions span wise either...