How much camber are you running?
I've been running CS22's outdoors on my 415 with 1.5 of camber, and they are scrubbing on the inside edge.
I would try adding some more camber.
However, having said that....
For the BIWS at don valley, we had to run HPI 15-40's with a Orion 26mm inch up disk wheel, and I ran 2deg of camber. Tyres still wore on the outside edge.
I put this down to the soft wheel being squished (technical term
) under load, so much so that the outside of the tyre was wearing the most. (the wheels are very very soft)
So i could just be the wheel you are using.
What are you using on the CS22's?