Tips on a Tri Bike?

Hey there, sports fans. If you're like me you can't wait for warmer weather - although it looks like tomorrow will be a decent day to ride in the northeast: 60 degrees and sunny!

I'm thinking it's time to invest in a tri bike. I currently ride a Trek 5000 carbon road bike. It's fitted with aerobars, and my positioning is tweaked to utilize during the triathlons I compete in. It's served me well, and even carried me through an Ironman last summer. That said, I can probably do better.

I have a few ideas on what kind of bike I'd like to purchase, but would love to hear your thoughts and experiences. I want to keep total cost under $3k, and lower if possible.

Can anyone help?