4-5 hours of near zero temperatures and constant rain? I run pretty hot, but I haven't found any arm warmers that would work for me in that.
IME Nanoflex are good, but they are just normal Roubaix warmers, with a bit of silicone on the fabric so that most of the water runs off. Good for warmish wet days, and for quick blasts, but not enough on their own for long winter rides. That's not what they're made for though.
4-5 hours of near zero temperatures and constant rain? I run pretty hot, but I haven't found any arm warmers that would work for me in that.
IME Nanoflex are good, but they are just normal Roubaix warmers, with a bit of silicone on the fabric so that most of the water runs off. Good for warmish wet days, and for quick blasts, but not enough on their own for long winter rides. That's not what they're made for though.