Is this similar to the D09C effect where if you have the ability to actually activate the sponge it has strong catapult but if you don't it feels dead? A player at my club has the Z but I haven't had a hit with it yet so curious.
Not really, it’s just a little more bouncy than you would expect, more so after it has been played in.
D09C has a small amount of tackiness in comparison to Rakza Z, but the R Z sponge isn’t like BTY spring sponge X.
With most rubbers with harder sponges, it can be harder to activate the sponge, especially if you have been using rubbers with softer sponges and grippy top sheets.
Try putting a rubber protection sheet on a tacky top sheet, drop a ball and let it bounce until it comes to rest. it will bounce for longer than if you do the same test without the protection sheet. For me, it’s the level of tackiness that gives the initial ‘dead’ feel.
Obviously just letting a ball bounce doesn’t activate the sponge, so you have to try playing!!
Some of the older Gen Donic Bluegrip rubbers have 4 different sponge hardnesses. This really gives you the chance to compare how the sponge hardness really helps or hinders, the level of tackiness is the same. So it’s a good way to compare.