its the grinding surface on the threshold, its too close to the wheel so whenever i hop into them my wheel just bounces off the ledgeI don't see how you can 5-0 on a lindworm but not on a threshold aha
You can do them fine on a Thresh once you get used to it. My mate 5-0'd a cement ledge a decent distance before he cut his deck for pegs and I learnt 5-0s first day on my Thresh.