Recently fitted some Schwalbe 349 72 stud tires to my Brompton. I have other bikes with studded tires better suited to deeper snow, slush on ice etc, but my commute is sometimes fairly clear except for icy patches which I don't wish to encounter going downhill quickly or any other time, actually. Most of the posters here seem to be British and I have no idea how much ice and snow you have to deal with, but if you do and don't relish the idea of falling down you might give these a try. They really increase the effort needed to move the bike but I found their grip tenacious on ice, included rutted ice that was a slushy mess the night before and then froze hard overnight. Fairly easy to mount, certainly no harder that standard marathons.