High-vis jacket for warmer days?
 

Starting around 45 or 50 degrees F, the wool/fleece underlayer is too much, so I've been wearing the jacket over just a T-shirt. For comfort, this works OK, but because the jacket doesn't breathe (even with open pit zips), it traps body odor. Would a light windbreaker do the trick? Still highly visible but lighter and more breathable?

A lot of us wear a vest for 2 of the choices.....

Carhartt makes a fleece sweatshirt, in ANSI reflective striped neon lime..

Safety equipment, I got mine in a shop selling work clothes .. , here.

I like to get my visibility from my vest in the darker winter months. They layer up well with no added heat realy.
http://farm7.staticflickr.com/6055/6...c2b75087_m.jpg

Then jacket underneath my vest is probably of a similar weight to that second lighter Bontrager jacket and would work well for what you want. This is my do all jacket, its just a second hand running jacket I got for a deal. From 30-70 even higher if it might rain. I just layer things under that and have never had any problems. I almost never use my thicker jacket,(I have used 2 windbreakers) but it just doesnt get as cold here in Oregon as it did in Illinois.
http://farm8.staticflickr.com/7032/6...140f1cd8_m.jpg
I did add some reflective iron-on tape for more visibility(I don't like to stand out so much off the bike)

I've got this jacket from Performance.

http://media.performancebike.com/ima...-HVY-FRONT.jpg

I had some problems with the zipper after about six months on the first one I got, but I took it back to the store and they gave me a replacement for something like 50% off the sale price I originally paid. It's been a decent jacket. It's very lightweight and very bright, but it's about as waterproof as a paper towel. That doesn't really bother me on warmer days. The other problem I have with it is that it's very baggy and flaps in the wind like nobody's business.

If I were getting something less cheap, I'd probably want removeable sleeves.

One of my sons got me a hi vis yellow compression shirt for Christmas. Works great under a jersey as it is very light, very tight and very bright.

I have a Saucony ViziPro Sportop long sleeve mesh shirt that I wear when running at night. It's super light, not water or windproof, but I wear it as a top layer. I just looked online & found a place selling them for $23. I bought mine for full retail price. Works great & is very versatile, as I can wear whatever I want underneath (I would buy it one size bigger than normal, to allow for other layers underneath)

I've got a Castelli Leggero wind/rain jacket that is pretty decent for riding on warmer days. It is not as waterproof or warm as thicker rain jackets, but lighter and more breathable. The whole jacket folds into a small bag about the size and shape of a hamburger. What I like about it is that it's so compact and light that I can carry it in my seat bag or jersey pocket on days when there is a threat of rain, and it takes up little space and adds virtually no weight. I would not recommend it for daily use, however, because it doesn't look like it would hold up but it is great for unexpected or light rainfall. It is available in black, white and high-viz yellow (which is what I got).

I use lights and reflective material to make me more visible, and us a small backpack with retroreflective trim on it when it's warm. I don't notice a big difference between the high viz vest and an highviz long sleeved jacket when I wear it, both make me more visible than riding without either one.

This is the one I use and I like it for all four seasons.

http://www.alertshirt.com/wirajaancl3.html

http://ep.yimg.com/ca/I/alertshirt_2191_1945348

Froghunter

I have one similar to this http://users.accesscomm.ca/sarr/prod...range_Vest.jpg