I had an old road bike frame with the shifters mounted on the down tube. I like the frame because it was quite light for an aluminium frame, only about 1.7+ kg and the aero design. Since I prefer disc brake rather than calipers brake, I decided to rework the frame so that I can use disc brake plus some changes to the cables routing and an additional water bottle on the seat tube. Here are the brief details of the work done;
Here is the finished bicycle, a Gravel Bike running 700x32C tyres.