Gravel racing is one of the more unique disciplines of cycling. Its a discipline that heavily relies on bike set up. Tire choice is course dependent and each course is vastly different. Courses can include smooth gravel, rough gravel, single track and road; all with varying percentages of each.
With such a difference in terrain choosing a tire is difficult. Inevitably on some parts of the course you will be under-tired and some over-tired. In gravel, there is never one right answer for tire choice but, here are my guidelines I follow when choosing a tire.
Optimizing for Critical Sections and majority of the terrain
In every race there will be certain sections of the race that will be critical to your result. Those sections can be a climb, single-track, a large section of chunky gravel, etc. Once you’ve identified the critical points of the course next is looking at what type of terrain you will be racing on.
Race organizers will have the course on their website, and those contain the percentage of pavement to dirt. You can also poke around on the website to find pictures of the race from previous years to see what the terrain looks like, or if you’re lucky sometimes there are videos on youtube that detail the course. Picking a tire that is best suited for critical sections of the course and the majority of the terrain is usually your north star for tire choice.
Example #1- Low Gap
For this year’s Low Gap Grasshopper race the most critical point of the race is the first climb. This is where the section selection happens, it’s vital to have a fast and lightweight tire to make the selection. Looking at the terrain, the majority of the course is paved and the gravel on this course is mostly smooth. So, with this course knowledge in mind a fast tire with minimal tread would be ideal.
For Low Gap I decided on 35mm Specialized S-Works Mondo tires. These are the widest road tire specialized makes, with more durability than their strictly race oriented road tire. The Mondo was light and fast to get me up the first climb fast but also with enough durability and grip to get me by on the gravel.
Example #2- Sea Otter Gravel
Sea Otter offered a much more dynamic course and it had me scratching my head trying to figure out what tires to run. The critical points were the start and final climb. For the start you needed a fast set up to get up the track fast, but enough grip to keep up on the fast gravel decent.
Then for the finish a lightweight setup to get up the steep final climb. This course was mostly dirt but there was a significant amount of pavement. These factors made tire choice more difficult than usual but I knew the gravel was going to be really fast and loose so I wanted tires that had a lot of grip.
After testing a few different set ups I went with the biggest tires I could fit on my Crux- a 2.2 Specialized Renegade up front and a 47 Specialized Tracer in the rear. I sacrificed a bit of rolling speed opposed to if I ran a traditional gravel slick. However, the sacrifices I made were minimal and it was worth the extra grip on the fast loose gravel.
Bicycle Rolling Resistance.com
For tire nerds like me Bicycle Rolling Resistance.com (BRR) is an excellent resource to find and compare tires. You can find the rolling resistance of almost any relevant tire. If you cant find your exact tire, you can usually find your same tire in a different size and you can use that data to draw a reasonable conclusion for your tire.
Example #1- Low Gap
For this race I was deciding between a big road tire or a skinny gravel tire, and I was curious how these tires stacked up against each other.
Looking at this BRR, the 35mm Mondo is about 2 watts faster than the 38mm Pathfinder. With that knowledge I was willing to sacrifice the grip and puncture resistance of a gravel tire for the speed of an endurance road tire.
Example #2- Sea Otter Gravel
The setups I was playing around with was either running 42 S-Works pathfinders or a 2.2 Specialized Renegade up front and a 47 Specialized Tracer in the rear. BRR doesn’t have any data on the tracer but Specialized advertises both the pathfinder and tracer as their race tires; so I can assume they have a similar rolling resistance.
Comparing my choices here it looks like 47 is about 1 watt slower than the 42. This isn’t a significant difference for me and I was okay with taking the 1 watt penalty for a lot extra grip. Next up was seeing how the 47 stacked up against the 2.2 renegade.
This isn’t exactly an apples to apples comparison since the tire I have is the renegade in a 2.2 size and non-S-Works version. However both tires use the T5 compound in the middle so, again I can assume that they are similar.
On BRR for CX/Gravel tire testing, RR Low testing is conducted at 31psi. Using the data from the 47 at RR low and the renegade tested at 35psi, the renegade is about 2 watts slower than the 47. Again, not a significant difference so I was okay with that small watt sacrifice.
What are other people running?
Now this is a tricky strategy to use when picking a tire. Its easy to fall into the trap of comparison and getting too focused on other people. Just running what everyone else is running just for the sake of it, isn’t a good idea. Your set up is meant to work for YOU.
However with that being said, I list this here because digging around on instagram for bike checks or looking into the race website for photos from pervious years can be helpful in guiding your decision making process. Sometimes if there are trends towards a certain set up its worthwhile to look into that set up to learn why its being used.
Using a setup that you feel comfortable and confident on
Adding on to what I was saying above your set up is meant to work for you. At the end of the day you should feel comfortable and confident with your choice. Your set up needs to fit your riding style.
If you’re a rider that doesn’t have as much technical skill as other gravel racers but you’re confident in your fitness; taking some penalties running bigger tires to boost your handling might be a worthwhile sacrifice. On the other hand if you’re a strong technical rider but you’re worried about having the fitness to keep up; running a faster rolling setup and sacrificing grip could be the right choice for you.
With gravel racing no matter what you choose you will always be on the wrong tire in certain sections of the course. Tire choice comes down to optimizing for critical sections and majority of the terrain. Also, using a set up that you feel comfortable with and that can help even out your strengths and weaknesses.
Sources
- Bicycle Rolling Resistance: Rolling Resistance tests. Bicycle Rolling Resistance, reviews of bicycle tires. (n.d.). https://www.bicyclerollingresistance.com/
- Gravel. Life Time Sea Otter Classic. (2025, April 12). https://www.seaotterclassic.com/gravel/
- Low gap. Grasshopper Adventure Series. (n.d.). https://www.grasshopperadventureseries.com/low-gap