If the spokes are hinged in flap AND lead lag at zero distance then it is not possible to rotate them at all. If they were already spinning then a change in axis of rotation would have no effect.
If the hinges (still at zero distance) were only free to flap and rigid in lead and lag then of course you could spin it. If you then changed the axis of rotation of the hub it would be equivalent of the NON free lead-lag hinge imparting a force which is in the original flapping direction. So for the 90deg
either side of the phase position which corresponds to the axis about which you have attemted to rotate the wheel's axle you have been urging the point mass at the end of the spoke to rise (or fall) - NATURALLY by the end of that 180degs the point mass will have achieved the maximum displacement from the original plane of rotation.
This is just an explanation of what people refer to gyroscopic procession. I don't think it helps people to understand it to 'hide' behind the term GP.
NOTHING really happens 90deg AFTER anything even with gyros. You spend 180deg pushing something up it gets to be high by the end of that pushing up process.
It certainly doesn't help to just tell people to use the mathematical function of taking the CROSS product of the INERTIAL MOMENTUM and the APPLIED MOMENT vectors - the result of which, by using the RIGHT HAND RULE, predicts something happening 90deg from somewhere else. CALLING this gyroscopic precession and pumping it out to the science student body and leaving them to figure a way to explain this APPARENTLY mysterious phenomenon to folk like LU just clouds the issue.
Sure there are still a few sin functions floating around - but the only reason to use them here is to bamboozle old ladies. To conclude - still '90deg later'.