[qbasic_forever]

I've used all kinds of traction tires in real world conditions over the years and say otherwise. Yes, brand new snow tires are far better than all seasons on ice. But after a few months the soft rubber on them will deteriorate and they're just the same as all season, but now with the added 'benefit' that you have no idea this has happened until you try to brake on ice and it doesnt grip as well anymore. I honestly think snow tires on ice do more harm by making people without winter driving experience overconfident in their abilities (same problem with AWD).

That said snow tires are still spectacular and necessary in snow. I buy and use snow tires every winter season. They are invaluable. I just am saying don't drive with them on ice and expect to have any better traction.

In real ice events/situations the tire chains come out or you just stay off the road, it's that simple. No amount of perceived driver skill, AWD techno buzzwords, etc. will save you on ice--you need hardened steel cutting into the ice.

[nkurz]

Expanding on your excellent answer, the real difference between studded and unstudded winter tires isn't just how the perform on ice, but on ice as the temperature approaches freezing. At very cold temps, the unstudded actually have an advantage. The ice is too hard for the studs to penetrate, and the softer rubber of the studless stops a bit shorter.

But as the temperature warms to freezing and the ice gets softer, the studs really come into their own. The studded tires have an even shorter stopping distance than they did at 0F/-20C, but the unstudded start sliding and almost never stop. In the worst case, the stopping distance can be almost 3x longer than the studded!

Here's an accurate (although biased) summary of a Russian study about this: http://www.skstuds.ca/2015/10/04/the-studless-tire-deception.... Clicking through to the Google translate of the original gives even more info.

I live in Vermont, and use studless winter tires for the winter months. On snow they are great. On cold clear roads, they are much better than All Seasons. But if you hit black ice on a thawing road, you need to know that they will not stop you the way a studded tire would.

[analog31]

I appreciate your comment. While I think my snow tires have helped on ice, I'm hesitant to make a broad claim about them without quantitative evidence to back me up. And I certainly take all precautions if there might be ice, ranging from slowing down a lot, to staying home.

Now, I love my carbide studded bicycle tires. Those definitely do work on ice. But once again, staying upright on ice involves a combination of those tires and other precautions such as slowing down.

[Moru]

The size of the bicycle tires are also important, and the air pressure. I changed to a fatbike without metal studs this year and now I can bike with very low pressure. Normally around 0.5 bar when bumpy and slippery, it works like a charm as long as it's not smooth ice covered with snow. The tires shape themselves around all the cracks and bumps and gives tracktion almost everywhere. The old bike with thinner wheels didn't have as good comfort in winter even with new studded tires because I could not ride it at that low pressure without getting damages to the rubber.

I live in an area of Sweden that has ice and snow at least 4 months per year. Still thinking of buying studded tires for the fatbike but want to see how I'm doing with these, the rubber is nice and soft even at -20 degrees so I think I might be good enough with this solution.

[danw1979]

Studded bicycle tyres work great on wet leaves too.

[divbzero]

This fits my personal experience. I don’t think I have ever slipped in snow when using snow tires. In fact, I have seen big all-wheel drives slip and slide in all season tires while my small front-wheel drive maneuvered just fine in snow tires. Driving in ice, on the other hand, feels just about as slick with or without snow tires.