ORIGINAL: spiral_72
IMO.
The ailerons on most trainers are undersized to do any rolls. I know mine won't. If high rates and adjustment on the control horn won't do it..... A guy at my field has a trainer that he glued 8" of 1-1/2" x 1/8" balsa sheet to his ailerons. While it's not pretty, I assure you, it'll roll now! I was suprised how agile his trainer is, wheras mine floats.
They are undersized? [X(] Hadn't heard that before. While they may be too small to do the 4-5 rolls per second that some people like to do, I've seen plenty of trainers do rolls. Heck, I was even taught to do rolls with my trainer, which didn't even have ailerons!