My winter ride uses 35mm marathon extremes, which I don't think they make anymore but are pictured here next to a marathon supreme. I don't feel like they are the limiting factor in my slower winter rides. More the heavier panniers and erring toward over rather than under dressing. If I were aiming to commute closer to 20mph I might not want them but I can't commute closer to 20mph and avoid road hazards etc...