If you are new to tubular tires/wheels, the Grifo Pro Series Tubular from Challenge is an ideal choice for cyclocross racing. If offers the classic tubular "look" with black tread and distinctive brown sidewalls, and it's handmade by Challenge without breaking the bank.
Pro riders get equipment free and can afford to have multiple tubular wheel/tire combos for grass, mud, dry, asphalt, etc. to suit the day's conditions - a luxury those of us who pay for tires cannot afford! A Grifo tubular feature an all-around tread pattern that works well on many surfaces - providing a single setup you can use with confidence in almost any race conditions. If you can only have one tubular tire/wheel setup, make it a general-use tread pattern like the Grifo.
SuperPoly 300TPI casing and PPS puncture prevention allow you to run very low PSI for increased traction and better handling in the worst conditions.
TECH NOTE: this is a tubular bicycle tire with a captive (stitched-in) latex inner tube (also called a "sew-up".) It must be glued or taped onto a tubular rim for safe use. It will not work on a traditional clincher wheel/rim. Proper setup is essential for your safety - if you are not qualified to install tubular tires, please seek expert guidance first.
I put the tire on the wheel to stretch prior to glueing and put air to it. The tire does not hold pressure for more than an hour. I know the other Challenge tubulars I have slowly lose pressure (over multiple days). I want to call and ask a couple questions before I have my local mechanic glue the tire on but just have not had time. I’m guessing air pressure will hold better after glueing. I will try calling soon. Your customer service and follow up have been great.