All frames go out of alignment when they are welded and heat treated. The solution is to put them in a jig and bend them back into shape. However, if you’ve ever tried bending a piece of metal to get it exactly where you want it (think maybe a disc roter) you’ll know it’s nigh on impossible. You can get it pretty close but really fine alignment is very hard.
The Nicolai Right Aligning Drop Out (RADO) comes in 5 different adjustment vertical positions. That sorts out vertical alignment of the wheel (making sure it’s precisely in line with the head tube). The dropout also slides back and forward to sort out horizontal alignment – when it’s precisely correct the frame is drilled and pinned so a replacement dropout will go in exactly the right position. This precise alignment is one of the reasons Nicoali’s track so well (and one of the reasons they cost a bit more).
Rectangular tubes are more resistant to bending loads than round – that’s why we use them on the rear triangle. Again, it contributes to the overall stiffness of the frame.
