I have done plenty of long rides on my S1 - which is aluminum, and VERY stiff. Rode from Toronto to Montreal on it with no comfort issues at all.

Tire choice helps. I'm a big fan of the Vittora Open Corsa EVO CX 320 tpi tire. It is smoother at 130 PSI than most tires I've tried at 100 PSI.

Really, if the bike fits and you have a saddle that is compatible with your particular posterior geometry, frame construction really doesn't make that much of a difference. Yes, the "comfort" carbon bikes like the R series Cervelos can take some of the edge off - but it's not like riding a super-stiff bike is an exercise in torture.

DG

My Cervelo S2 and P3 bikes are as comfortable as bikes of that type can possibly get.

My S2 is as comfortable as my '06 Specialized Allez E5. /shrug. Get fit, get a saddle that agrees with your taint and sit bones, collect win.

sweet super stoked now, thanks everyone for the input, much appreciated. i picked up some contis gp 4000s off of pbk a few weeks ago, and i plan on using those tires when i make the switch. but i've heard they run a little better at a higher psi..??? is that correct

This. I wouldn't mind if I could fit 25mm tires in mine, but a good quality 23mm tire and a saddle that fits your butt is fine for as long as you need.

Cyfac Mythique TT frame picked up on Ebay and set up as a road bike. I really like riding it a lot - very stiff but smooth and comfortable. It does have short head and top tubes, so the stem is a 130 and the seat is pushed back in a setback post.

http://www.cyfac.fr/Pages/Products/P...roductId=15012

http://i832.photobucket.com/albums/z...fac-garage.jpg