I just read the latest issue of Triathlete Mag and they have a great article (Apr '08, p. 82) called "SPEED FOR SALE". During the triathlon bike leg, your goal is to go very fast with a low energy cost, right? Aerodynamics is about 75% of the equation here and 60% is YOU, the rider! They depict a chart of products and their relative value in training. Look at them as "bang for buck" and they are in order of importance:
Clothing - 100 ($80-100)
Tires - 80 ($80)
Aero Helmet - 46 ($100-300)
Training Tools - 18 (powermeter $800-3500, coaching $75/mo., hr monitor $75)
Positioning - 16 ($50-200)
Fork - 14 ($300-500)
Aerobars - 9 ($200-500)
Wheels (front and rear) - 7 ($1000-3000 per pair)
Frame and Fork - 7 ($2000-4000)
Frame - 6 ($2000-3500)
Ceramic Bearings - 5 ($150)
So, let's look at a pile of money you might have and figure out the best way to spend it. Buying last year's tribike, which has a forward seat post allowing you better positioning (flat back, lower frontal area, ability to tuck in arms) should run about $1500-2000. A skinsuit runs about $100 at the most and the race tires should be about $80 at the most. A good bike fit should be free but if you have to go elsewhere, that should be around $100. (I highly suggest getting a trained eye to fit you and definitely go with a certified bike fitter who does lots of them). An aero helmet at the cheapest runs $100.
If you really wish to improve, look at getting a coach and a powermeter. You could hire them for 6 months prior to your big race. Nothing smoothes out your pedaling and gives you self knowledge like a power device. It's more accurate than heart rate, gives instantaneous information, and helps the athlete control work load in headwinds/tailwinds and uphill/downhill. Also, the triathlete can map out improvement much more precisely.
All said and done, you're out $2300 for the bike, skinsuit, tires, and aero helmet. You can rent race wheels on race day. Another option is to buy disc wheel covers for your rear wheel over the internet for about $100. Then, you could buy a used Hed3 front wheel or Zipp404 for about $500-700.
Some will say "just train more" and I do believe that. However, there are ways to wisely spend your money to get major bang for your buck. In short, a $3500 bike and $1500 set of race wheels may not be the way to go up front. Maybe it's wiser to start with a tight-fitting skinsuit, aero helmet, race tires, and pay a professional bike fitter $100 to look at your position on your current bike (road or tri), all for about $380?
