I've been out riding quite a bit lately in Kelowna and the temperatures have been around 6 C probably. I'm having a problem with my tires, especially the rear, getting no grip at all. They are Bridgestone bt014's and they gripped really well when I put them on last August but now they slide all the time. Its really annoying because I have to corner way slower than I would like to. Is it just because the roads are still so cold due to the low temperatures or did the tires harden up over winter?