It's on a fairly new and not super low end Dahon folding bike, but what a lousy design. It's cup-and-cone, I got the left side adjustable cup off fine but this fixed side is stuuuuuuck. The closest tool I could figure out for it is Park HCW-11 but I got nowhere with it even with washers clamped down tight over both sides (I'm turning clockwise to loosen). Anybody got a better idea?