I spend a fair amount of the year running on snow and ice. After trying all different kinds of ice running products, my favorite product so far is the La Sportiva Hobnail.
These wicked little units are made with a tungsten alloy head in some sort of metallic base. The threads are deep and more like an auger than a screw.
The Hobnails work differently than other types of traction devices as they just screw into the bottom of any old show. I tend not to like some of the products that slip on over the shoe as while this may be ok for a short run or walk, I don’t like the way it modifies form and collects snow for longer runs.
Things I like about La Sportiva Hobnails:
1 – They work in any shoe.
2 – You can pattern them in your shoes however you like. Put lots in or just put a few in.
3- They are removable and portable between shoes.
4- They last a long time. I have over 1000 km’s on my current set and they are still looking good.
5 – You can use them on rock. I’ve run them on slippery limestone karst and they work exceptionally well.
6- Believe it or not, these things work very well on wet wood like bridge decks or even roots. Since you don’t notice them on the trail, I put them in for runs where I know I’ll encounter wet rock or wood.