Originally Posted by
Moisture
Going from 120mm OLD to 130mm can be done, but many don't suggest it. You will destroy your rear hub bearings if you dont cold set your frame within 1 or 2 mm on each side.
Forgive my bluntness but one has nothing to do with the other. A properly adjusted axle will prevent any axial forces from impacting the bearings. The threads on the cone coupled with a properly tightened lock nut, prevent axial forces on the bearings unless the threads fail, which is a extremely low likelihood. So low that it would be described as "impossible." Compression of the axle has about the same likelihood.
Now the moment arm between the DO and the bearing location can cause an axle failure, if using a freewheel configured hub, with a bend of the axle at the bearing, causing failure. But we are discussing =>8 speed blocks which implies cassettes.