I installed studded tires on my CX bike yesterday afternoon. Forecast said there'd be a few flurries overnight, but no accumulation. Great, I thought, I can put off riding this bike. I'd made up my mind to take my other commuter with the slick 25mm tires, just because I hate riding the spikes.

My own neighbourhood was fine. About a mile out I noticed a dusting of snow pellets on the road. After another mile these snow pellets had be rolled over by cars and had made the road very slick. I pulled off the road, turned 180 and rode the sidewalk until I got back into my own neighbourhood. I took the car. It was too late for me to switch bikes.

Lesson learned: When it doubt, use the spikes. It's not worth taking the risk.

So my question to those who have a spike and non-spike option: How/When do you decide which one to take under marginal conditions like this morning?