I've all but given up on where jackets unless it's really cold (for here), maybe 40ish, and even then it tends to warm up to the point where a jacket isn't necessary. I have a PI jacket with removable sleeves, but without the sleeves the body is too loose to use as a windbreaker. My favorite colder-weather gear is deFeet arm warmers, deFeet short sleeve under shirt, jersey and PI windvest. I'm easily good to 45 degrees or so and since I don't ride a 0500 I've seldom seen anything below 40 degrees.