Leaderboard

You center rod (straight tube) would just need to have a matching inner diameter. That being said, as you know, I'm not a proponent of tapered rods in a quad, messes with the flex ratio imho. Also, these spars are a bit too stiff for that application - they're really better suited to a good dual line, where you don't want the designed shape to distort - stiffer spars also help them wind "break" for stalls and slack line tricks.