n00b needs Tri Bike Geometry Advice
 

I plan to ride a bunch of bike before doing anything. That said, I'm an experienced road rider that has never been on a TT or Tri bike ever. What are the key measurements, and how do they need to compare to my roadie? I see most here ride a smaller bike for Tri than road. I'd like to weed out some models before testing. Should I look for a top tube 2-3cm shorter or shorter still? For those of you tha have them, do you actually use the multi seat tube angles? This bike will be strictly for TT and Tri. All advice welcome. - Thanks

I'm new to Tri but I have done some TT's. I have a TT bike as well as a road bike. My advice would be to get a really good pro fit done right up front. A lot of good coaches do this and you could get the numbers from someone who isn't going to try to sell you something.

You'll save yourself a lot of trouble by doing it right the first time around. If you're taller than 5'3", which I'm guessing you are, you will have a lot of choices. At my height it's a pain to find frames of any type.

I am taller than 5'3", and I have a really good relationship with my LBS, so that is something I'll do first. Thanks

Another thing you may want to ask about is whether they can do the fit with a powermeter (powertap or computrainer). That may help you when it comes to dialing in the fit - where can you produce the most power. Or course, there is the aero component too. You may want to check out the road racing forum and send a note to DrWJO, he is a TT monster. Racer Ex is also good too. Both those guys may have some suggestions that would help before you get too deep into this.

Keep in mind that the most aero position may not be the most comfortable. I had the chance to talk with Dede Barry about this. In preparation for the olympic TT she spent a lot of time in the wind tunnel. The position that gave her a good balance between aero and power output was not comfortable at all, but she learned to deal with it. Keep that in mind and that it might take a few months to adapt to the new position, whatever it ends up being.