John & Gany:
Below is a picture of 3 bearings (obviously)...
Top: XRAY 13x19
Bottom left:XRAY 13x20
Bottom right: Avid 13x20
See the difference in the outer race of the Avid bearing (bottom right) and the XRAY 13x20 (bottom left)?
Avid kept the inner race the same size as the 13x19 and only changed the outer race to take up the gap in the new bulkhead.
This is also why everybody asking for bigger bearings over the last couple years doesn't understand a bigger bearing is not always better...
When you have a finite space to put the bearing in, you have to keep the size of the balls and the cage that bears them the same size and can only adjust the races to accommodate the bigger space.
When you increase the size of the inner race, you create a longer distance for the balls in the bearing to travel. So if you have the XRAY 13x19 and the XRAY 13x20 and each complete 1 exact revolution, the balls in the XRAY 13x20 will have to travel father by a factor of the change in diameter of the race and 3.14(pi). And when you introduce time in the equation: Say the the XRAY 13x19 and XRAY 13x20 both complete exactly 5 complete revolutions in 2 seconds, the balls in the XRAY 13x20, have to travel at a faster rate to complete those 5 revolutions in the same time as the 13x19.
What Avid did is only change the outer race, minimizing the size of the inner race, thus minimizing the speed and total distance the balls in the bearing travel.
John, more specifically, you should pop those rubber seals out of the Avid bearings and face the metal shields out.
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