3. What is a group and why is it important?
The group is the package of components that accompanies a bike, consisting of shifters, brakes, derailleurs—all the shiny stuff that hangs off the frame. Two companies have the market cornered here, Shimano and Campagnolo. Both are established and very reliable. Each company has put together a hierarchy of component groups that get lighter and perform cleaner as you go up the price chart.
Campy (as it's affectively known), a classic Italian manufacturer, has five groups (top-of-the-line Record, Chorus, Daytona, Veloce and Mirage), but tri-bikes typically feature only the top two, Record and Chorus. Their stuff is known for being very durable. In the past, it has been known to be a bit heavy, but that is rapidly changing.
You'll find Shimano, however, on 90 percent of the bikes out there. Their hierarchical breakdown, from race-specific to entry level, reads: Dura-Ace, Ultegra, 105, Tiagra, and Sora, with the top four being found on tri bikes.
4. What's up with that fat, strange-shaped tubing?
For the most part, unless you average 28 mph, the bladed down tubes serve only to make the bike stiffer, not to provide a huge aero advantage. There is a decrease in wind resistance at speeds of 21 mph or so, but the benefits are very minimal. You can cut most of your time with the proper aero position on your bike and by investing in deep-dish aero wheels.
5. How important is the fork?
Critical. You'll find most are carbon fiber (the softest, most shock-absorbent material), which is what you want when a lot of your time on the bike is spent over the bike's front end in the aerobars. If you look down while riding on a pitted section of the road, you can see the fork blades actually flexing, deflecting the focus of the shock forward on the tire and wheel instead of up into the bike and the rider.
6. What's the difference between a 650c and a 700c wheel?
Not much. Proponents on both sides have said that either creates less rolling resistance, and 650c lovers contend that the wheels have less frontal wind-catching area. Debatable, still. All told, the big boys (six-foot and up) are more stable on 700c wheels, and smaller guys and women are often set up nicely on 650c wheels.
7. Do they have these bikes at Costco?
Not a chance. Tri bikes are somewhat of a specialty item, so pick up the phone book and go to as many bike shops in your area as you can. Check out the shop. See how many tri bikes, accessories and clothes they deal and stock. Ask questions. See if they have a triathlete working who can answer tri bike questions.
In most reputable shops, when you buy a bike, you've also purchased the service and experience of the sales staff. If they don't show immediate interest in talking to you and ask specifics about what you're looking for, move along.
Alright, you have the basics. Remember that all of the major players have a website. Check them out to get more information on how their bikes are made, the company's philosophy and reputation. Don't forget to take catalogues of the bikes you're interested in home and pore over them, comparing frame design, kit options and prices.