Originally Posted by
cyccommute
I have never found a situation where punching through anything provides a more stable ride. If a bike punches through sand (similar to punching through snow), the bike bogs down and is harder to ride. It's harder to steer and harder to keep power to the rear wheel. There are lots of instances where we design ways of getting on top of the snow...snow shoes, skis, snowmobiles, fat bikes, etc...to make the going easier. A narrow tire that punches through the snow is analogous to post holing across a snow field with your feet.
Sand=snow is silly. There is no road beneath the sand so of course a skinny tire will harder to steer, and have poor traction. The tire has nothing solid underneath to provide stability. And skis, snowmobiles et.al have a huge contact patch that prevents the user from sinking into the snow, as does a fat bike at 8 psi. I have yet to see anyone ride in snow that is 15 inches high either, your post holing analogy seems pretty silly too.
Skinny tires cut through the snow so the tire is in contact with road. Same reason mud tires for mtb are skinnier. To get through the soft stuff and to get some purchase at the bottom. I never understood the rational of using wide tires that allow the rider to 'float' over the snow. Floating IMO is a nice way of saying the tires slip all over the place and provide no traction or stability. I ride 23's at 115psi in the winter. Tires are on the road, not slipping, provide great traction as they are gripping the road, not loose, soft shifting snow. I have studded mtb tires for another bike and hate them for anything other than a thin layer of snow that might be hiding ice. As soon as the snow if more than 1 inch the bike gets all squirrelly, the treads fill with snow, and the studs cant even come in contact with any ice. I've used wide2.25 tires at26 psi, same issue. The bike shifts and slides.
Where I live almost all the winter riders have skinny tires, granted the roads are routinely plowed and salted so the majority of the days are snow free. Alot of the commuters I know only have one bike and switching tires/wheels for different conditions might not be an option so they stick with the skinny tires.