I've tried using the graphite shims. The problem is when you get you ride height to where it should be, you still have no structural support. The aluminum spacers included will, indeed, crush. The graphite shim needs to be modified out of the pakage to work. They released the brass set screws because the steel ones damaged the kingpin and didn't set very well. And they were released along with the front end. Why not just include them?
All in all, the performance of the front end is spectacular. When I was putting it together, I thought "WOW....why didn't someone think of this sooner?". The pivot ball is awesome. Including the different caster blocks is awesome. The adjustability is awesome. Durability? Uhhhh.....not so much.
Granted, I haven't been doing this for too long. I still hit stuff. But when a guy that has been racing on a national level for years and years breaks 4-5 arms in one day on a track with relatively soft borders, there's a problem somewhere.
Jason