Anyone done it successfully, on a Fidlock or similar?
It turns out the bottle bosses on my frame can only take the manufacturer’s own non-adjustable Fidlock base, which is positioned such that the only bottle that’ll fit is the Fidlock 600. That’s the one without a flip mud cap, and of course Fidlock have different threads on each cap style which aren’t compatible so leak.
The 590 (type with flip cap) almost fits but they’ve changed the offset of the bottle along the mount by a few mm, so the corner of that bottle contacts an internal corner of the frame. I need to reduce the protrusion marked by the red line, by about 5mm: