MSR tents utilize high-performance nylon fabrics for their exceptional balance of strength and weight. While nylon is the best choice for lightweight tents, it can display subtle property changes with changes in humidity. In winter, when it’s cold and very dry, you may find your tent fabric seems much tighter than in summer, when humidity levels are higher. Nylon also stretches when wet. In our testing we found that nylon tent fabrics stretch at least 3.65% after going from very dry to wet. This is normal, and our tents are designed to accommodate this fluctuation.
If you are having difficulty attaching your rain fly to the top cross pole, try spraying some water on the rain fly, and let it sit for at least 5 minutes. This will allow time for the fabric to stretch so that you can attach it to the cross pole.
Alternatively, if you are pitching the tent with a second person, have your tent mate attach one side of the fly to the cross pole and stabilize that side of the pole. Reach your hand under the rain fly and apply upward pressure to the cross pole so that it bends/arches upward in the middle (the poles are designed to bend this way). This will shorten the distance between the ends of the cross pole allowing you to attach the fly to the opposite side of the cross pole.