Originally Posted by
sp00ki
the point is still moot. no matter how much force is applied to the cranks, the necessary action required to loosen a lock ring cannot be created by the cranks. in one direction (pedaling forward), the cog moves-- "tries to", more accurately-- away from the lock ring; in the other (locking up, skidding, etc), the cog uses friction to tighten the lockring while the lockring is subsequently forced to "use" the reverse threads as leverage to tighten itself against the cog.
the only thing the cog can do to free itself is push the lock ring hard enough to rip the threads off of the hub.
correct me if i'm wrong.
Not sure I can correct you if I only have a theory, but humor me...
when you skid and loosen an improperly installed cog so that it butts up to and tightens the lockring, since both are tending towards the same centerline, neither moves a significant amount (very small). The force this applies isn't enough to do much real damage in the form of mashing threads and killing the hub.
BUT once you apply clockwise torque on the cog by going forward again, the two are rotating together as long as friction holds the two together (normal force is decreasing over this period as friction spins the two together) and tending away from that centerline thus, the cog tightens and the lockring loosens. Again, the movement is very small, but perhaps more than in the first case when the two were coming together.
Over many such cycles, the lockring is gradually loosened to the point where it is engaging an insignificant number of threads on the hub and the force of the loosening cog shears off the remaining engaged threads and buggers your hub.
'course, this is all theorizing that I've never dealt with since I (try to) make sure the durn thin's on rite.
/high horse