our SPF and STF urethane can not be graded on the dero scale because it is a superior formula that has characteristics of multiple wheels. what i can say is that they are hard as hell and can still grip while going as fast as you can through your favorite pool or park. and when you need to slide out of a trick or grind, its a controlled slide.
oh I know there hard John. They are about as hard as SPF I think, also fast as crap and fun on skatelite for sure. Thats why I wanted to clarify above and say not as good as SPF. If you do skate street at all, then STF would be the better all around wheel. SPF seems to vibrate on non smooth concrete or streets and STF rides better. I only ride my SPF's in parks and pools. For street I actually use and old set of Autobahn wheels, cause I had em and I'm too cheap to buy some STF's for my street board I ride once or twice a month LOL! Good catch John, I should not have discounted the STF's for park and all around use.