interesting, the guy at the shop said something similar. so as grease get hard, does that make the pawls less able to engage? would that explain the slipping? i check out the chain for stretch and its fine, teeth on the cassette look good to. it totally did the lurch thing again so much so that it threw the chain off the middle ring while under load. its a fulcrum hub if this make any difference. im going to take it apart and inspect the grease situation.....thanks for the tip.....