The Brompton front luggage system is quite brilliant in design & operation. Robinson, my first Brompton, came with a C bag & it gets lots of use. When Ralph, my second Brompton, came along & I also setup the Bromptons with on-board tools & bidon cages, it was time for a second luggage bag – but one of a smaller size.
In my research the Ortlieb Mini-O bag seemed ideal but I found it was a teensy bit small for an iPad. Rather than use this as justification for purchasing an iPad Mini along with a Mini-O bag, I looked at what I could adapt.
I found a handle-bar mount bag that would fit my iPad, camera, etc & then fabricated an alloy adapter plate to attach to the bag’s support system.
On the road it’s been working well. My alloy adapter plate is admittedly now at version 2.3 but I’m pretty happy with it. (Certainly gives me a better appreciation of what goes into the Brompton & Ortlieb bags & frames?)