Tire Valves vs. Wheel Sizes
Comparing 2 standards across 19 specifications. 19 key differences identified.
Bicycle inner tubes and tubeless systems utilize three primary valve standards: Presta (Sclaverand / French valve; 6 mm stem diameter, manual locknut tip, rated up to 15 bar / 220 psi), Schrader (American / Auto valve; 8 mm stem diameter, spring-loaded central pin, ISO 4570 thread, 0.305"-32 TPI), and Dunlop (Woods / English valve; 8 mm stem diameter, drop-in core).
Bicycle tire and rim dimensions are standardized internationally under ISO 5775 and the ETRTO (European Tyre and Rim Technical Organisation) system. Sizing is defined by two numbers: nominal tire width and Bead Seat Diameter (BSD) in millimeters (e.g. 28-622). Major standards include 700c / 29er (BSD 622 mm), 27.5" / 650b (BSD 584 mm), 26" MTB (BSD 559 mm), 650c (BSD 571 mm), and 20" BMX (BSD 406 mm).
Specification Comparison Table
19 Parameters| Parameter / Spec | ||
|---|---|---|
|
Presta Valve Stem Diameter
|
6.0 mm (0.236 in / narrow drilling for narrow road rims) | — |
|
Presta Operating Mechanism
|
External Threaded Locknut with captive brass plunger pin Manual Lock | — |
|
Presta Maximum Pressure
|
15.0 bar (217.5 psi high-pressure road tolerance) | — |
|
Presta Rim Hole Requirement
|
6.5 mm (0.256 in diameter hole in rim) | — |
|
Schrader Valve Stem Diameter
|
8.0 mm (0.315 in / identical to automotive tire valves) | — |
|
Schrader Thread Specification
|
0.305-32 UNEF (ISO 4570 8V1 thread) Standard | — |
|
Schrader Rim Hole Requirement
|
8.5 mm (0.335 in diameter hole in rim) | — |
|
Dunlop (Woods) Stem Diameter
|
8.0 mm (uses 8.5 mm rim hole, manual rubber sleeve / core) | — |
|
Common Valve Stem Lengths
|
32, 40, 48, 60, 80 mm (extended for deep-section carbon aero rims) | — |
|
700c Road / 29" MTB BSD
|
— | 622.0 mm Bead Seat Diameter (ISO xx-622) |
|
27.5" MTB / 650b Gravel BSD
|
— | 584.0 mm Bead Seat Diameter (ISO xx-584) |
|
26" Mountain Bike BSD
|
— | 559.0 mm Bead Seat Diameter (ISO xx-559 classic MTB) |
|
650c Triathlon / Road BSD
|
— | 571.0 mm Bead Seat Diameter (ISO xx-571) |
|
20" BMX (Standard) BSD
|
— | 406.0 mm Bead Seat Diameter (ISO xx-406) |
|
20" BMX (Race / Junior) BSD
|
— | 451.0 mm Bead Seat Diameter (ISO xx-451) |
|
16" Folding Bike (Brompton) BSD
|
— | 349.0 mm Bead Seat Diameter (ISO xx-349) |
|
Road Tire Width Range
|
— | 23.0–32.0 mm (e.g. 25-622, 28-622, 32-622) |
|
Gravel Tire Width Range
|
— | 35.0–50.0 mm (e.g. 40-622, 47-584) |
|
MTB Tire Width Range
|
— | 53.0–66.0 mm (2.1–2.6 in / e.g. 60-622, 65-584) |