For the past several years, race-fit jerseys with wind- and waterproof membranes have been dominating the racing and training scene from Europe to our home region of Northern Utah. The key to these jerseys' versatility is the stretchy membrane at their core, so it's strange that people tend to think of the company sewing the garment rather than the company building the membrane. The C5 Gore Windstopper Jersey Zip-Off Jersey corrects that oversight, providing a jersey that protects like a jacket and bears the imprimatur of the company responsible for the membranes that inform the genre. Like the would-be usurpers, the Windstopper Zip-Off is built around a Gore Windstopper membrane, which is also the same membrane used on the short-sleeve version. The obvious difference here is that the Zip-Off model includes sleeves that effectively function as raglan-cut arm warmers, extending the Windstopper protection from neck to wrist when the weather warrants it but zipping off and disappearing when the clouds clear and the sun shines through. The slightly roomier C5 fit accommodates layering, too, so it allows space for extra thermal warmth if you're not ready to call it quits for the year when winter rolls in.