So you want to do the Iceman but you're a but you're not sure about the bike leg. Well, you're not alone. As those folks who bike year round in any northern city that receives appreciable snowfall can attest to, most people seem to think it's pretty nuts. I'm here to assure you that it's really not. In truth, other than the lower temperatures, there are fewer differences than you might think. The tips below will get you riding through the white stuff on two wheels in no time.
1) Traction. Traction on snow is varies widely. While riding across an ice rink would typically require special studded tires to avoid catastrophe, most surfaces you'll be riding on in the winter (and in particular during the iceman triathlon) will be easily navigable using standard knobby mountain bike tires. The trick is simply to lower the pressure on the tires (somewhere between 10-15 psi - or until they seem pretty low) so that more of the tire is in contact with the ground. This has the dual purpose of increasing friction on packed snow and/or ice and giving you a bigger footprint on looser snow (i.e. groomed snowmobile trails).
2) Corners. Once you stop worrying about slipping while riding, you'll likely fine that going straight on your bike in the winter is just like going straight in the summer. Cornering, especially if you're using standard tires, is another matter. Until you get the hang of things, slow down at the corners. Coming into a corner with speed requires you to lean significantly to negotiate it, which may cause your tires to slip out. Slow down so you can steer more with the handlebars and remain more upright on your bike. As you learn to read the various surface conditions you'll become a better judge of when this caution is necessary.
3). Stopping. Often in the winter you're riding much slower than in the summer and so stopping is quite easy. However there may be times (like during the race) when you're still moving quite quickly. While stopping on packed snow or loose snow is very easy, stopping on ice or the packed glaze that you find near some intersections is not. When in these situations, bike like you drive - slow down well in advance, and remember that if you brake on ice, you'll simply slide.
4). Trails. Riding on groomed snow mobile trails is awesome - but taxing (unless you've got one of those nice snow bikes with the 4 inch wide tires....). It is possible however, at least in most conditions, to ride these trails with a standard mt. bike tire. As mentioned above, low tire pressure will help dramatically. In addition, it is important to try to keep a smooth cadence and a constant momentum. the moment you try to stand up and mash on the pedals (the way you might do in the summer) to go faster, the back tire is more likely to spin quickly in place and dig itself a nice little trough to rest in. My best advice is to get out there and practice.
5). Balance. If you're nervous about falling over, make sure you ride with flat pedals and lower your seat a bit while you're getting the hang of it. Being closer to the ground will enable you to use your feet to keep from falling if the bike starts getting squirrelly as you push through a slippery section. Once you gain confidence, you'll be surprised what you can ride through!
6) Core temperature. Yes, it's cold outside - but if you plan well, you don't have to be cold when you're riding. Your core will actually heat up very quickly if you're managing any sort of a pace, so avoid the temptation to overdress. I'll usually wear a thermal/base layer on top and bottom beneath a light wind proof layer. It is best to keep the wind layers as snug as possible. You will sweat (so no cotton on the base layer!) and a baggy outer layer will let that moisture accumulate further from the warmth of the body where it will freeze and you'll end up with a layer of ice INSIDE your jacket.
7) Hand and Feet. This is where you need to pay special attention. Unlike when you're running pounding the blood into your feet and swinging your arms, when you're biking your hands are static (and gripping something which lessens blood flow) and your feet are being robbed of heat more effectively because of the greater apparent wind. A big warm winter pair of boots will suffice (though it's heavy and there are more elegant options) and heavy, insulated windproof mittens are a must for most days. Layering is fine to achieve warmth for both hands and feet, but make sure nothing is too tight - your feet will be much warmer if the boots are slightly too big than if they are too small.
8) Head. Your head is your best option for regulating your body temperature. I try never to go riding any significant distance without the gear to totally cover my head, face, and neck. I typically start out fully ensconced with hat, goggles, and face mask and then intermittently pull down the face mask or lift the goggles to cool off. Whether you believe or not that more heat is lost through your head than other parts of the body (quite a debate about this, believe it or not), headgear remains the most effective way to cool off or warm up without getting off the bike.
Now get out there and start riding! And check out the facebook page regularly for information about some expert led group rides leading up to the Iceman where you can get more first hand knowledge from those crazy folks that bike 365 days out of the year. And if your one of those folks - lets have your comments and tips as well!