I have the HB bag mounting parts for 3 bikes ready for the plating shop. I've decided to use Electroless Nickel Plating, with a glass bead blasted base. All 3 of the handlebar decaleur mounts are different, because the stems are different. The one in the middle clamps onto the bars, I'm using a Cinelli 1R stem so no clamp bolt. The one with a stud is for a 1A stem, the other one is for my Singer. These decaleur parts are fiendishly difficult to make, at least the way I did them is! The small "U" shaped tube thing mounts onto a Merz front rack, this allows the French style handlebar bag to be mounted.