2:1 gear ratio in stud-less Lego Technic Is there a recognised technique to create a 2:1 gear ratio in stud-less Lego Technic?

Neither of the two methods suggested here (studded though) work.



24T/12T with a 2L x 1L axle offset does rotate, but is too stiff to be functional.

16T/8T with a 1L x 1L axle offset is totally jammed.
Here's a solution I found in Yoshihito Isogawa's LEGO Power Functions Idea Book Vol. 1 - Machines and Mechanisms:





EDIT
based on Eric's comment:





And here's using the black piece from JohnnyB's tweak: