Winter Bicycle Tire
57mm x 700C Schwalbe Ice Spiker Pro Kevlar bead tungsten carbide studded tire. $400 a pair, ouch. I use these for commuting in northern Canada. Schwalbe makes a cheaper studded road tire but it freezes at -25 and becomes even slower than the knobby Ice Spiker Pro.
The background is the downtown Edmonton, Alberta bike lane known as the Oliverbahn.