I’m debating my tire setup for Unbound this year. Considering a Race King up front and Pathfinder Pro 47 rear if dry. I ran Pathfinder Pro 47’s F/R last year and Pathfinder Pro 42’s F/R in 2023, both with good results and no punctures. I know there are potentially faster tires than the Pathfinder, but I value durability on that course and have had good experience with them.
Anyway, today was a long endurance ride and it was a good opportunity to do some tire testing. I was planning 2 loops of a 54 mile course, so figured I’d do a loop with the race king up front and then a loop with the Pathfinder 47. Not super scientific, but it was a good day for it. Low winds, pretty flat course. ~2/3 of the course was mix of pavement and very tame dirt/gravel and the other ~1/3 was medium gravel (nothing crazy). I know based on prior testing that the race king is faster on chunk, so I was really interesting is how they compared on a tame course like this. Identical bike setup except front wheel/tire. Wheels same width and depth. Raceking at 23psi, pathfinder at 30psi. Tried my best to keep same position on bike, including predetermined sections where I used the aero bars.
Results - Exact same NP an AP on each lap and my time in each zone was within a couple minutes of each other. So yeah, I’m a bit of a robot when it comes to riding endurance… Race king was just over 2 minutes slower. And there was one section early I think the race king got a small advantage with wind being just slightly lower at the start (based on looking at data), so I’d probably say the race king was more like 2:15 slower. Which translates to about 7 watts at those speeds (a little over 18mph). But it was hotter (lower air density) on the second lap accounting for 2-3 watts. Assuming my logic is directionally correct, I’d guestimate that the Race king was ~5 watts slower today on a pretty tame gravel course. I assume that gap might grow a little at race speeds. Again, I know this isn’t the most scientific test, but feel that’s it’s directionally reasonable and thought it might be worth sharing. Apologies for this post being such a rambling mess, just too lazy to figure out how to present it better.
And I’m not bagging on the Race King based on this, I actually thought it might do worse with all the road/smooth sections. I’m seldom struggling for watts to stay with a group on the smooth sections and I’ll take an advantage on the technical and chunky sections all day if it doesn’t cost me too much elsewhere. I’m planning to do a bunch more comparison testing in late April when I’ll be in Kansas pre-riding and doing a gravel stage race. I’m also racing this Saturday and plan to run the race king up front.
