Pearl IzumiMen's Pro Alpha Layer(Return to Product Page)

Seems so light and insubstantial, but traps air very effectively and insulates more like down. I wear it over a thin merino wool base layer, and under a light wind shell or a heavier soft shell jacket�depending on the temperature. A bit pricey, but you�re buying a versatile layer that can be used with stuff you already own to adapt to temperatures from pretty cool to very cold!

Polartech alpha is a great material. Not sure what voodoo they use, but it always punch above it weight and you cannot go wrong wearing it as a mid layer. As outer layer, it does not work for anything below 60F.

This PI jersey is a little odd. Since it is a mid layer, I cannot see any reason to add rear pockets. They only add unnecessary bulk and expense. The other glaring issue is the fit. It�s generous with woefully short sleeves. Unless you have T-Rex arms, the sleeves will walk 2-3 inches above your wrist, the minute you get into riding position.

Other manufacturer make better polartech alpha jerseys

I wear this over a merino baselayer and under a thermal jersey for rides in the low 40's, upper 30's F. Very warm and fits snug in between layers. Very impressed with how warm this is without being bulky at all.

I'm 6'3" 41in chest and normally wear a large jersey. This in large was so tight it felt like I'd rip it. Exchanged for an XL and it was baggy, but the arms still not quite long enough and torso still too short. Unfortunate because it seems like a great piece of kit and is warm and breathable. But be aware fit is I guess more suited for shorter torso, and if XL, thicker over skinnier I guess.

Like the title says. Best under something highly breathable, pretty darn good even if not.

My first reaction was how is this going to be warm....OMgosh... What a mistake. This is a warm layer. Not a windbreaker, which is what makes it great for cool rides and very breathable to not even need to take it off when climbing hills. Pearl Izumi... You nailed it on this one.