@Rich Duperbash @Ole Fart51 I know this is a semi-old thread, but just got my Backflips in today, and am wondering what you're having to drill here? What's the purpose? Does anyone have a picture of this?
Thanks!
Dremel out the wheel hex hole a little or it can be difficult to get the wheel off/on. Cover over the vent hole in the wheels, then drill a new hole in the rubber of the tyre. That's all that's needed.