I've been caught out before with new tyres, Very expensive. What I do now is before I ride with new rubber is take some course sandpaper and scuff all over the tyre, don't rub too hard or you'll shorten an already short life for miles. When you have finished take a petrol soaked rag and wipe around all of the tyre, you will see that it lifts all of the wax coating off the tyre. If you like you can give it another light scuff with the sandpaper. The tyre should not feel slippy any more, but remember it is not a sure fix for riding slowly for a short while to get some heat into the rubber before you start getting your knee down.