Even just a few years ago, we were still suggesting front pressures as much as 8-10% lower than rear pressures, but as our data set has grown larger, we find that some of the most successful CX racers at the professional levels are running front pressures within between 0-3% lower than the rear. We’ve even found that front pressures are occasionally higher front than rear if the course has particularly steep downhill sections with roots, rocks or other obstacles where
rim and tire damage seems to be more concentrated on front wheels.
Tire size and choice. We strongly recommend the largest tire you can fit in your frame or if
you are racing UCI, the largest tire that will fit within the rules. There are no courses or conditions we have ever seen in cross that favor narrower tires. For years the conventional wisdom was that narrower tires were faster on
harder pack surfaces when conditions were dry. It was believed that the narrower tires would roll faster at slightly
higher pressures and also that the reduced weight was a significant advantage. Modern data collection
combining power measurements with highly accurate GPS have shown this to really never be true. The weight advantage of a
1-2mm narrower tire is very small and the rolling resistance penalty to higher tire pressures on rough surfaces can be quite high. For this reason, we recommend the lightest, most supple tire you can find at the widest width you are allowed to use in
your event. And of course, if you are not running tubeless, then you MUST be running latex tubes whether you are
riding clinchers or tubulars. Latex tubes have lower rolling resistance by as much as 3-4 watts per tube, are more
resistant to pinch and puncture flats, are lighter weight, and provide significantly improved ground feel through the tire. It has been shown over and over again in testing that riders on latex tubes are not only faster at the same power
output, but also have a better feel for what is happening at the contact patch of the tire.