I'm doing a 212-mile ride on Sunday, and am having trouble deciding which of my bikes to take.

I have a Trek 5200 (carbon fiber racing bike) set up in a fairly aggressive riding position. I did Calvin's Challenge on this bike earlier this year... and although I was thrilled with my finishing position, my butt and my back paid the price. I was really sore the last four hours of that ride. I also used the Trek to do the Ride Across Indiana, and again, I finished well, but was really sore. I have tried many different saddles on this bike, and have come to the conclusion that racing bikes just aren't made for comfort, no matter what saddle is used.

I also have a Surly Long Haul Trucker, set up as a commuter. It has drop bars with a moderate position - slight drop from saddle to hoods. It has 28-cm tires, and a Brooks B-17. Unfortunately, with rack and fenders it weighs just under 30-lbs. But it is all-day comfortable.

Sunday's double century will be at a light to moderate pace (average speed 18-20mph), since the speed of the group will be restricted to that of the slowest rider. The first half will be fairly hilly, and the terrain will become flat in the second half when we start across the plains of Northern Indiana. We will have SAG support every 50-miles.

Which bike would you take? The weight and "touring" gear ratios of the Surly concern me. And the lack of comfort aboard the Trek 5200 is a problem.

Someday, I'm going to get a Marinoni sport touring bike... but that's years ahead.