Why tire choice can make or break a gravel race
If you watched my Turnhout POV, you saw how the course—long, flat, firm gravel roads with high average speeds—shaped every move on the bike. Tire choice isn’t a small detail on days like that: it decides how fast you roll, how you corner, how many attacks you survive, and whether a stray shard of glass ends your race. Below I’ll explain why tires matter, what trade-offs to weigh, and how to translate those choices into a race-ready setup. I’ll also point you to a few solid research and test sources I used while writing this. (If you want exact parts and pressures I used at Turnhout, check the “What I Wore” sidebar and printable checklist on this page.)
The big-ticket reasons tires matter in a gravel race
Rolling speed vs traction
On firm, hard-packed gravel (like large sections of Turnhout) rolling resistance becomes a primary performance factor. Modern lab tests consistently show tire construction, casing suppleness and tread affect rolling resistance more than just nominal width or weight. In many cases wider tires on a given rim and at realistic pressures can roll as fast or faster on rough surfaces than narrower, higher-pressure tyres because they deform less and maintain better contact, especially when the surface isn’t perfectly smooth.
Puncture risk and DNF prevention
Gravel races expose you to thorns, glass, and sharp stones. Tubeless setups with sealant significantly reduce the odds of small punctures ending your day because they often seal cuts automatically; that’s a major reason many racers go tubeless for events. There’s still a trade-off, heavier puncture-protection layers add rolling resistance and weight so pick the level of protection that fits the course.
Comfort, cornering, and speed retention
Lower pressure increases comfort and grip, which lets you carry speed through rough sections and corners instead of bleeding velocity over bumps. That comfort also reduces fatigue over a long race. But lower pressure raises the chance of pinch flats (if you’re running tubes) or rim strikes if you go too low on tubeless so use sensible ranges and a pressure calculator where possible.
How course type changes the right choice
Turnhout was effectively a fast, hard-packed day: long straightaways and firm gravel encouraged sustained high speeds rather than technical, muddy singletrack. On this kind of course, the priorities shift toward lower rolling resistance and aerodynamic efficiency without sacrificing enough grip to justify very knobby tires. In short: race-oriented, fast-rolling gravel tires (moderate tread, decent casing) and a tubeless setup are sensible starting points. Pro race averages at Turnhout were in the ~40 km/h range, a reminder that some gravel races are essentially high-speed pacelines.
Practical rules of thumb
Tire width
Fast, hardpack / mixed pavement (Turnhout style): 35–45 mm, modern data supports slightly wider tyres for real-world speed on rough surfaces, but you don’t need aggressive knobs.
Loose, muddy or technical courses: 45–50+ mm with more aggressive tread for bite and control.
Tubeless vs tube
Go tubeless for racing if your rims and tires are compatible, the sealant gives you the best chance against small punctures and lets you run lower pressures safely. Keep a tube and CO₂ or pump as a backup.
Tread pattern
Low-knob or tightly packed center tread for fast hardpack.
Larger, spaced knobs for loose/muddy terrain to shed mud and improve traction. (If your race mixes surfaces, choose an all-rounder or a slightly faster tread and lean on corner technique.)
Tire pressure
Use a tailored pressure rather than a single psi rule. Factors: rider weight, tire width, rim internal width, and surface. For many racers on firm gravel, somewhere in the 30–40 psi range is a reasonable starting point for 35–45 mm tires, but adjust up for heavier riders or very smooth sections and down for rough or wet conditions. Tools and calculators from manufacturers can help dial this in.
Protection layers & casing
Supple casings reduce rolling resistance and feel faster, but reinforced casings or additional puncture belts reduce flats at the cost of weight and some speed. Pick the level that matches the race risk: high speeds + low debris = lighter/supple; sharp junk on course = more protection.
Race setup checklist
Confirm tire/rim compatibility and tubeless seal.
Run a realistic pressure test in the days before the race: try a slightly lower pressure on a training loop similar to race surface and note handling.
Bring a spare tube, CO₂ (or pump), a tire boot and a small bottle of sealant for quick top-ups.
If your race is mostly fast hardpack, choose a fast-rolling gravel tire (moderate width and low knobs). If it’s technical or muddy, go wider with more aggressive tread.
Know where feed zones and neutral support are; even good tires can’t stop every DNF — have a plan for quick mechanicals.
What the tests and experts say
Lab rolling-resistance tests show casing and construction often outweigh simple width or advertised “race” labels in determining real-world speed; wider tyres can be faster on rough surfaces.
Tubeless is widely recommended for gravel racing because sealant often prevents small flats that would otherwise end your race.
Manufacturer pressure calculators and guides (use them) help convert rider weight and rim/tire width into a working psi window, far better than guessing.
Recent group tests rank tires by a balance of grip, rolling speed and puncture resistance, a reminder that no single model is always best; choose by course.
Final note
In my Turnhout POV you can see how pack speed and the firmness of the course punished small mistakes but rewarded fast-rolling gear and clean corner exits. Tire choice was one of the invisible decisions that made the day feel so different from a technical gravel event, the right tyre let riders sit in long pacelines, stay upright through corners and avoid losing speed to rough patches.