That never registered before, but thats a good idea - my arms always get hot before anything else and its awkward just to roll sleeves up...go with light long sleeve underlayer and vest from 26-42 and w added light jacket below 26, depending on wt. of vest I suppose? Was thinking of making a makeshift vest by cutting off the long sleeves of one of my more throwaway race shirts...
I have to relearn this stuff every year. Keep thinking I'll make a little notebook to keep track of weather and clothing, but never do....
I've got 3 vests - a PI road biking vest which has a mesh back, very light weight, but good ata blocking wind. an mtb vest which is heavier material, no mesh back, i think, but it has rear pockets. and then the PMTR vest which is inbetween the other two, has side pockets and a solid back.
The key is wind blocking. I don't think a chopped-off race shirt will do much for you. You could Just wear a ss shirt over or under instead. You don't have a vest with all the riding you've done?
My fav is the PI since I'm usually wearing a pack of some sort. You'll have to play with the temp range. I think 42 is too warm for me to wear a vest.
I ran today with a ss top and a ls top, no vest. 38F and was just about perfect.
Yeah, I want to keep notes too, but seems like the cold effects me more now. what you describe for 38 is pretty typical for me. this shirt I'm thinking of is pretty thick, so it would be good for torso, and the long sleeve is very light, arm warmer material, so I think it might work. prob 30 or lower. good to explore all the options!