That's very perceptive of you to notice that.
Whenever I hear a description of a turntable functioning I get excited and giddy. I go into this sort of change, everything else seems not to exist and time stays still. I think it is because with every single element of function that a turntable does, there is a way to get evan more fidelity out of what is already the highest fidelity known. To hear elements of performances of the greatest musicians known to man, To realize artifacts of sonics that reveal the humanity of talent that evan possibly was not noticed during the origional performance. To transmit information through sound that was never heard, or thought could be, laying bare the souls of poeple the transcend sound into a living, breathing, piece of emotional history of passion, exitement, soul!
Anyway, you have my curiousity. It is normal for an arm to carry resonences from the cartridge, in fact, it is desirable for the arm to transfer energy from this back through the arm and away. But I have never heard an arm be louder at the bearing than the cartridge. Usually, when these ideals are met more the cartridge actually gets softer sounding. (thats what I have perceived). I am curious as to whether my rb-300 will do the same thing, as I have never thought to listen to this on it.
I wonder, could it be the coil spring that controls the trackong force resonating? Could it be that energy is being trapped at the bearing because it is not being absorbed by the plinth? Could it be soundwaves escaping from inside the armtube and that is the easiest place to hear it?
Whether or not these are true does not nessesarily mean that there is something wrong with your arm, though, so don't misunderstand my thoughts. I would not take it as something that must be alleviated. (provided everything is sounding the way you think it should). Luckily, some things that might alleviate it are things that you would want to do anyway, like the heavier counterweight, which will change the spring pressure, adjust or experiment with the tightness of the mount, stuff the arm with foam, and last but not least, the HIFI mod, which I have tried and found to be worthwhile. Contact the very same TWL above. (TWL, aren't you curious as to what your HIFI would do for his desribed condition?, anyway, if I were in his shoes, thats what I would do).