A key piece for your winter wardrobe when the days grow shorter and temperatures drop reach for your primal heavyweight jersey it39s a heavier weight than a standard long sleeve jersey offering that bit extra insulation something you39ll welcome as it gets colder it is ideal for forming the basis of your winter riding wardrobe adapting to any weather with heavy or light base layers and outerwear worn solo with a lightweight baselayer for cool quick rides or combine with a merino base a