After experiencing CX last year on my MTB with cx tires and having a great time, I decided to step it up this year. One of the major factors on a CX bike is being able to run low tire pressure to allow for better traction and added suspension to smooth out the rough spots. The down fall of running low tire pressures with standard tires/tubes is the possibility of pinch flatting or rolling the tire off of the bead on the rim. Pinch flatting is where the tire impacts an object hard enough that the rim slams down on the the tire "pinching" the tube between the tire and the rim causing a flat. Pulling the tire off the bead is exactly what is sounds like... the tire doesn't have enough pressure to keep the tire hook into the bead of the rim and it comes off. Either scenario will force you to either DNF or run for the pit to swap wheels or bikes. Either way you are going to loose a lot of time and cost you positions in the race. The solution is to run a tubular tire which is basically a heavy duty tube with tread attached that is glued to a special style of rim. This solves the issues described above and also reduces the rotating weight, lightening the bike and increasing acceleration.
After doing some research and talking with some racers, I decided to go with the Tufo Flexus Primus tubular (http://www.tufonorthamerica.com/tires/elite.php?seriesid=51). This tire is a little more expensive than some of the other brands out there but makes up for it by being more durable and easier to mount and true. This particular tire has been completely revamped for 2009 to improve suppleness (ride quality), decrease rolling resistance (By 10%), increase durability and improve wet traction. Tufo was very responsive to my questions and easy to deal with. Once the tires arrived, I had them mounted up to my Revolution Wheelworks REV-25X wheels (http://www.revolutionwheelworks.com/REV-25X.html) and ready to go for the Waterford Double Cross weekend.
After 3 races, I am thoroughly impressed with these tires. They roll with ease and smooth out the bumps, but what they do best is corner. Each race I have pushed them further than the race before. They have instilled confidence in my abilities and have allowed me to maintain speed in critical corners. One cool feature that I have noticed is that they have an audible growl in the corners that reminds me of being on my MTB!