Tri bikes don't have to comply with UCI regs. One of the more noteable one's regards the positioning of the front of the saddle in relation to the bottom bracket.
Also a bike optimized for triathlon takes into consideration the fact that you have to run when you get off the bike.
Without the constraints of UCI regs, the seat can be further forward, and a steeper seat tube angle, making it easier to run when you get off the bike leg.
However, unless you're looking at the definition of a UCI legal TT bike, there really is no clear distinction between a TT and a Tri bike.
Tons of triatheletes for example ride Cervelo P3's, which is also used in many TT's.
The bike I TT on, a Griffen Vulcan, was marketed mostly to the triathlon crowd, but it certainly used by people in TT's.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
Last edited by merlinextraligh; 05-14-09 at 08:36 AM.