Have not been encountered.
Each day i come to the shed and the bike is still covered in snow from the day before, go on another great spin (often hub deep in parts) finish and drop the bike in the shed with no cleaning/lubing etc.
In fact I've not cleaned the bike in 2 months (once in 12?? - either you're lazy or you don't ride much, the rest of your bike is crying out for a clean) and it's still shifting perfectly!
