Ask ten riders for their tire pressure and you get ten confident answers to the wrong question. Pressure isn't a preference — it's a system property. Rim internal width, measured tire width, rider-plus-bike weight, and surface roughness set the number; taste only fine-tunes it.
Start from measured width
A 28 mm tire on a 23 mm internal rim measures closer to 30. Measure the casing with calipers at riding pressure, and use that number — every chart that asks for 'tire size' means the measured one.
The rough-road discount
On broken surfaces, lower pressure is faster: the tire absorbs texture that would otherwise become vertical motion of you. Our rule from the test loops: for every surface class rougher, drop 10% — smooth tarmac to worn chipseal to hardpack gravel to washboard.
When in doubt, bracket
Ride the same 10-minute loop at three pressures, 5 psi apart. The fastest one usually also feels the calmest — speed and comfort stopped being a trade-off when tires got wide. Clearance sets the ceiling on all of this: the ExAero GR RDC Frameset takes 56 mm front and 52 mm rear, which is where the wide end of this advice comes from.
This is a test article — content is illustrative while the store is in staging.
