I'm training for IM-USA, my first long distance Triathlon. My current bike is a four year old Cannondale road bike with a triple chain ring and stock 105 components. I bought it for cruising with the local bike club. I went to a good shop, and it fits very well for riding 90% on the hoods. If I ride it at Lake Placid, I will probably average about 15mph. So I may flirt with the bike cut-off, but should be ok. I rode the main part of the Lake Placid bike loop during two visits this fall, and with the triple I can "spin" essentially the whole course.
I planned to buy a new tri-bike for IM-USA. My road bike would remain for group rides, and as my emergency bike for IM-USA if something went wrong with the tri-bike. As a kid I wrecked my 10 speed a few days before my first "real" bike trip, and had to ride my dad's heavy old 3 speed instead. Never again I hope!
However, I am also a big believer in technique. Not knowing of Power Cranks then, I blew much of my year's training budget on a CompuTrainer this summer. What sold me was SpinScan, and the ability to practice on the Lake Placid course in my basement this winter. I definitely have plenty of room for improvement, with SpinScan numbers in the 40's when cruising, bumping up to the low 60's when accelerating.
So should I invest in educating my legs with Power Cranks, or ease my paranoia and buy some speed with a new tri-bike?