Personally, I haven't ridden on a longer cruise in cold weather before. That said, I have a fair amount of experience camping in cold weather (used to be in Boy Scouts,we camped every month no matter what.) and I still daily drive my Ruckus on about a 40 minute commute, at temperatures that vary from 30-40 degrees. If you have any knowledge or tips to share that you feel should be mentioned, please post in the comments section. I'm always looking to learn, and I'd be happy to make some edits to add new info. All the information I'm posting here is assuming that you're riding in a temperature of between 20 and 40 degrees fahrenheit. If you're looking to ride in colder weather, good luck to you.
Let's start by discussing the potential dangers of cold weather, especially when riding. There are two things to be concerned with when riding in the cold; hypothermia, and frostbite.
Hypothermia occurs when the human body's internal temperature drops. This can happen even at temperatures above freezing. The best way to prevent hypothermia is simple. Layers of insulation, especially around your core.
Frostbite is perhaps more dangerous, if only because it can sneak up on you. Frostbite occurs when the cells in a localized area of your body actually freeze and die, causing permanent tissue damage. Frostbite is nasty, and not to be taken lightly. Do a Google image search for frostbite if you're curious. It's not pretty. Because of the windchill that occurs when when riding, it is also possible to get frostbite at temperatures above freezing. The best way to prevent frostbite is to make sure that all your extremities are covered, especially your ears and fingers.
Now I know some of you guys are thinking 40 degrees is nothing, but take this into account. If you're riding at 35mph, which is the average speed you're going to be hitting if you're on a stock Ruckus like I am, the wind chill will drop that 40 degrees fahrenheit down to 28, which is cold enough to easily get frostbite and/or hypothermia, especially when riding for a while. If you're taking a 15 minute ride over to your buddy's place, wear whatever you want, you'll probably be fine. But on an extended ride, such as the 3 hour-plus cruise I'm riding next weekend, your body temperature will start to drop, and it will keep dropping.
Take a look below at my current commuting outfit. This is what I wear when I ride to work in the morning:
This setup is what I use for dry weather between 30 and 40 degrees. On the high end of that range, it's a little warm. At the low end, once the temperature is below freezing, it's just barely enough. Ride in the cold for a while, and you'll quickly notice that the difference between above and below freezing is pretty big.
Starting at the head, I wear a thick hoodie, and tuck the hood under my helmet. While this definitely works, I recommend a ski mask. It's a lot more effective and can fit under tighter-fitting helmets. Underneath that I wrap a scarf. The scarf is important. Without it, I get a blast of cold air right on my throat. Not fun.
Over that hoodie, I wear two warm jackets. For me, one jacket is not enough, especially since both jackets are kind of loose-fitting. You can experiment to see how much you need around your core, but remember, if you let your core get cold, you're one step away from hypothermia.
On my hands, I wear a pair of leather riding gloves, with a pair of thin felt gloves over them just for a little added insulation. You can easily just wear a pair of ski gloves, although if the temperature is below 30, you'll want to add a pair of stretchy knit gloves underneath, which you can easily find at Target, WalMart, or even the dollar store.
On my legs, I usually just wear jeans and thick socks. This works well enough for a 40 minute ride to work, but it gets pretty damn cold on my legs towards the end of it, and can take half an hour or more to warm my legs back up once I arrive. I do not recommend just wearing jeans for a 3 hour ride. Seriously. My balls get pretty damn cold, and I don't want to lose them. You have two easy options. Either wear thermal pants underneath your jeans, or wear ski pants over the top. Either way, your future family remains intact.
That's about it. Please let me know what you think in the comments and on the Facebook, and look forward to a full account of Rucksgiving 2012 next week!