Try Panaracer XC Fire pro ... Great for mud and ice/snow
calm down nic, I did say WORN nobby nics :-P They were excellent when new! Bout time I bought some new ones, maybe I'll try Panaracer this time....will see what the bike shop holds.....
Just make sure you get the folding version ... a little more expensive but saves 90 minutes wrestling them on! You'll also then have to get some new summer later since they have a high rolling resistance on anything hard, compact and dry.