Scott,
That's a good question. By means of an answer, look at the size of the TRBs on your 'roid, and then recall the size of the TRBs that they used to put on the front end of whatever species of Detroit Iron you may have driven in days of yore. They were much smaller, yet each one supported 1/4 of the weight of the car with enough safety margin to handle all the live loads encountered from potholes, turns, curbs, etc. Then consider how long those bearings lasted. I don't think I ever had to replace a set of front end wheel bearings except when I tightened them too much once...ONCE!
But then again, you have a twin, so there are two power strokes 180 degrees apart, so your flicker shouldn't be as bad as that of a single.
Quinn