A little background- I am looking at an upcoming ride that will likely be somewhere around 5 hours in 30 degree F temperatures with a light wind. This would be the longest duration that I have attempted in this kind of weather. I am trying to figure out what to wear on top that will keep me warm enough as I seem to often be a little colder than some folks. I also don't want to be too hot and want some flexibility. If am afraid that if I under or overdress it will be a loooooong day.
I am considering lighter layering- maybe a base layer and jersey under a cross country skiing/active wear style jacket. It is some type of thicker polyester with a little fleece and huge pit zips. I am also considering a few layers such as a base layer, mid weight and jersey under a convertible windbreaker.
Any thoughts on the best option which would offer flexibility for a ride of this duration?
My advice would be your second set up. Layers with a windbreaker on top. IMHO 30F is not that hard to stay warm in if your output is constant. No question a thin wind blocking layer is the key. You can always remove a layer if too warm. I would wear a LS base layer, a LS wool jersey and a light windbreaker and regulate heat by unzipping the front. A skull cap under my helmet, and bring an ear covering headband in my pocket to switch to if I got too warm
Honestly my feet would be more of a problem over 5 hours than anything else. They always are. Depending on the type of riding I was doing and shoes I was swearing I might bring a some chemical toe warmers just in case.
On the bottom, I'd go for medium weight tights, wool socks, and plastic grocery bag halves between socks and shoes. I can usually deal with varying temperatures up top if my legs and feet are OK.
Up top, I'd go with 2-3 thin layers plus the wind (and water) proof top. Over 5-6 hours you can expect some variation in temperature, and you've got to be able to respond promptly so you don't overheat and sweat. Pit zips, play with the zipper, stop and take off a layer (or add one!) if necessary.
If you've got some place to carry them, an extra pair of warm gloves may feel pretty darn good after 3-4 hours.