I've assumed that this mod was really good at first back when I first got the wheel ( which I no longer have ) . But yeah if you guys are going to do this mod. You might as well find something flat and something really strong to resist the scraping and tearing that the ball bearing does. So yeah just a fair warning.
Its a great simple mod, dont get me wrong. It's just that you're going to have to keep changing the stack of phone, old credit cards, or whatever you use eventually. Which is sometimes too much of a hassle.