-
The first version is probably easier to manufacture, because the two ratchet rings are identical and the splined insert which threads into the hub shell only has to be centred well enough to allow the spline clearance float to take up the slack and allow the ratchets to be lock together concentrically. Mk1 has this float in both the shell and the freehub rotor, effectively doubling the allowable tolerance.
The new one has a short plain section on the insert to centre it in the hub shell, which is necessary because it also locates the centre of the drive side main bearing. With only the float of the moving ratchet ring to take up the slack, the ratchet must be made more accurately concentric on both the fixed and moving rings. If the ratchet rings can't self-align, any eccentricity results in all the drive load being taken by a small number of teeth, leading to accelerated wear.
These are related questions to the failure of the iQ² power meter - you can't rely on a threaded connection for accurate radial positioning.
You are reading a single comment by @gbj_tester and its replies.
Click here to read the full conversation.
gbj_tester
I was thinking that but assumed there must be some good reason for it that I was too stupid too see