Here is a quick look at the port geometries. The port area compared to the valve swept area is smaller for the WP valves. So if one of them were going to lock up at speed due to a valve port restriction it would be the WP valves. Did not look at the valve port deck height. There may be a difference there.
The fork compression damping force is plotted for the three tests. The AER damping force curve is digressive so it will end up with less damping force at high speed. But the difference looks to be small and probably due to the shim stack configuration used in the test.
Don’t see any reason for the AER to be significantly softer at high speed. With the smaller ports it should be stiffer than showa. Deck area differences may be worth looking at. The AER valve looks like it may have more entrance area than the showa. We should look at the ratio of deck area to port area to see if the entrance deck area is restricting the flow.
The other thing to look at is the shim stack. Don’t know if the AER test shown is typical of the shim stacks you are using. The one shown is digressive and if that is due to the shim stack opening it could get even softer at high speed.
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