so i have a motor laying around that i would like to throw in a bike. only problem being i would like it to be a bigger bike. it is for my fiance who would like to play bike ride, and i think a bigger bike might make it a little easier for her. something bigger then a xr70 if possible. the only frames i can think of this bolting into are the crf50 and 70 frames,,, am i missing one or are those my only two options. i would like to stay away from the older bikes like the sl70 and such. any opinions are appreciated.