All wing wheels scuff when glider turns if the wheel axel cannot turn. If the wheel fits wing very well this not a problem and you really notice it only when turning the glider while it's stationary.

Cobra, Schempp and many other older "unisex" wheels don't fit anything. Using them is based on trial and error, you learn to fit it to correct direction and then it sort of works, maybe 60% of the time.

SoarinXX wheel is huge improvement in design. I just wished the would have used real bearing on svivel joint instead of that flimsy plastic bearing. That has to carry wing full of water on uneven ground.