Good luck sliding these wheels! (OK for park / street cruising though)
You need lots more speed and perfect unweighing technique and still difficult with them... Would help if you go on something smooth like marble and if it's wet - but then be prepared because it can be quite unpredictable. if you stay low it'll be ok
When I was getting back into sliding, just to ease into it, I got some hard regular skateboard wheels on the S9 and it was sliding like nobody's business
Then I put on proper sliding longboard wheels after I had a couple of days on the regulars.
I still have the original S9 wheels - if someone wants them, pay for shipping and they are yours