yeah, mediums or softs? they werent proto wizards but I have cracked two black chalky wizards, both were tree hits after riding the wind and coming down w/ extra speed, one rim cracked, the other was flight plate.
I broke a soft while flexing it completely in half to create nice little thumb grooves I used to like. you definately need to be carful, and dont even bother bending mediums.
Z Pred-ESP Cyclone-Z Force-Z Aftershock-Z Comet-Ion-Pro Rhyno