The tray will definitely need to be extended if you're running servos heavier than 55grams. Mine sits with the rear edge of the tray in line with the triangle stock, and my batteries still hang off the front edge of the tray by about 3cm.

On a different note, I smoked my motor or ESC today. I doubt it's the motor's fault as Castle ESCs have a known problem with 28 pole motors, which I didn't know about until very recently. Ordered a Q80-14XS and a Mezon controller to replace it.

That said, the Shulman Aviation Fury motor was MORE than enough power for the BiSide that's for sure. I'm going to move that motor over to the new project when I get it back from Jason.