I designed new wedge keeping the seat on place of FirstBike. The oiriginal one broke.
I went through few iterations.
Nylon looks perfect now. ABS good. I tried PETG for older versions but it was breakable (cracks under load). PLA same as PETG - cracked.
Requires M8x40 bolt and nut (use original).
I recommend at least 5 perimeters and top/bottom layers.
.. ABS, Nylon