So I replaced the M Type stem on my Brompton with an H Type. It is 6cm higher, but the hinge is higher, too. I tested three stem adapters.
|TranzX double clamp adapter||SATORI Aberhallo Adjustable Stem||GUB G-80 folding bike stem|
|Distance||50 mm||50 mm||55 mm|
|Colors||black||black||red, silver, blue, black, gold|
|Remove Grip and break lever for assembly||No||No||Yes|
|H Type stem, GUB G-80 adapter and flat handle bar|
For now I am using the GUB G-80. The 5mm more make a difference (no conflict with the mudguard stay) and I like the look of the bands at the handle bar.
The handle bar is 1 meter from the ground and 8 cm lower then the saddle.