I just got back from one of the more interesting winter rides i have had in my 5 winters of riding. We have been having a light mist/drizzle for the past 36 hours and the temps have been in the low 20's to mid teens. The temp during todays ride was about 15 F.
Regardless, EVERYTHING is coated with a nice layer of ice. It isn't a thick crunchy layer of ice, but rather a thin, hard as diamonds type of ice. My Nokian Mount and Grounds showed that while they are decent for providing traction, they by know means make you immune to crashing.
My route today consisted of about 6 miles of gravel roads with a few hills in the mix. I could tell immediately upon entering the gravel roads from the paved roads, that things were going to be a bit dicey on the gravel roads. I kept feeling the front and the rear, give out from time to time.
On one of the steeper hills finally both tires broke loose when i was climbing and i laid the bike on it's side. It was a very unremarkable wreck, but it proved to me for the first time that studded tires don't mean you are immune.
I know these were probably the worst conditions i've ever ridden in, but part of me wonders if one of the more aggressive Nokians would have faired any better? I used to have a pair of Nashbar studded tires that i swear were better than these, but again maybe it's just my imagination because these were crazy conditions today....probably the worst i've ever ridden on.
Anyway, the tires were fine on pavement and of course on the treated roads. But they were pretty lousy climbing these glassy hill sides. Certainly changed my perspective of studded tires and ice. They don't make you bullet or in this case, crash proof.