For all of you "full-figured" RV-12rs out there, I think that you will find this gusset mod to be very useful. I can almost guarantee that at some point in your RV-12 flying future, the pilot and/or passenger will reach back and push real hard on the cockpit side rail resulting in a pretty good bow in the rail.
I installed a canopy lock similar to that shown in these pictures, but I cut a 1" hole in the gusset for future lock access (if ever needed).
David Heal - Windsor, CA (near Santa Rosa)
EAA #23982 - EAA Technical Counselor and Flight Advisor; CFI - A&I
RV-12 E-LSA #120496 (SV w/ AP and ADS-B) - N124DH flying since March 2014 - 650+ hours (as of July 2018)!
through June 2019.