Last year, when I first placed the order for my Ebisu, I went online to collect parts. One of the things I bought used for the build was an Inujirushi handlebar bag that Jitensha Studio imports from Japan. It had since been sitting with the parts that were to go on the Ebisu in a corner of my bike storage. I have since built up the bike and began to use it, but I wasn't able to find a good way to secure the bag on the front rack of the Ebisu. I did have a set of decaleur and bag mount from Velo Orange that can be used for this purpose. But I will probably ride the bike with some other smaller front bags from time to time and don't really care for the look for an unused decaleur sitting in my headset stack.
Then I came across Alex Wetmore's brilliant idea of using rail and hook for an Ortlieb pannier at the bottom of a handlebar bag to secure the bag's front end to the rack, and decided to give it a try. Since the width of the custom front rack on the Ebisu is only 10.5 cm, a top rail for the panniers is too wide. Instead, I bought some previous-generation lower rail and top hooks to create a quick release for my bag. I started by assembing the hooks with the rail, making sure that the combo will fit and clamp onto the rack with no problem. Then I mark the appropriate spots on the bag to drill. I drilled holes in the bag as well as the stiffener. Finally, I used screws that came with the rail to secure the hook/rail to the bag and the stiffener.
Together with the back-end leather sleeve, the home-made quick release keep the base of the bag very secure. I haven't tried riding with a full bag and see how stable the top end of the bag is under those conditions. I will report back after this weekend's rides.