so i am still in the design phase of this project. my basic idea is to get two vintage ladies' frames and weld them together side-by-side, keeping the rear wheels as is, and putting a fork between them for the single front wheel. i figure that besides the two whole frames, i'll need a couple of others to cut up and get the tubes for connecting the frames. my question is, what kind of bikes would be best suited for this project? i'd like them to be commonly found so that i can get them easily, and for cheap. also, i need to consider the frame material so that the pieces will be easily welded together. and as i said, i want the whole frames to be womens' frames. any help/advice would be appreciated. i'm really excited about this idea and have had tons of fun already just with drawing design pictures.