Lock de-icer...
 

... comes in handy. This morning I rode to an exam in the snowstorm we're having and locked up with my u-lock. When I tried to unlock an hour later, the key wouldn't turn. I had to walk home and get some de-icer.

Also, I may stop using the lock holder on my frame this winter. yeah, didn't quite think that one through.

Otherwise, snow riding with studded nokians and full fenders f-ing rocks.

Once the lock dries out put some graphite powder in the mechanism. It is made for lock tumblers and will keep it working smoothly.

Cool, I'll try that.