The Q36.5 Gregarius Winter bib tights feature a patented UF Thermo Plus fabric. This is an innovative material with an extremely tight knit that functions much more efficiently than traditional winter bib tights made from conventional nylon. The exterior of the material is nylon with a DWR treatment to protect the legs and back from rainwater and road splashes. The interior of the material uses a special hydrophobic polyester yarn that insulates while wicking moisture away from the skin. It has been designed and pre-shaped for the cycling position. The result is that you will not have excess material behind the knees that bunches up and irritates you while riding, for example. The minimal number of seams and strategically placed panels will ensure your freedom of movement without feeling pressured or restricted around the knees while pedalling. One of the reasons you may feel much slower in winter is that your leg muscles cannot warm up sufficiently.