Valve stem sizes guide

The selection of valve stem size primarily depends on the tire type, wheel rim hole diameter, and application scenario. The size standards for different types of valve stems vary considerably. The following is a guide to the dimensions and selection points for common valve stems:

I. Size specifications classified by valve type

1. Rubber valve stems (TR series, most commonly used)
   Suitable for tubed or tubeless tires of passenger cars, light trucks, and motorcycles, and are the mainstream choice for civilian vehicles.

Core dimensional parameters

1. Stem diameter: Common sizes are 8mm (suitable for most passenger car wheel hubs) and 10mm (suitable for light trucks and agricultural vehicle wheel hubs). It must match the diameter of the wheel hub mounting hole.
2. Stem length: Choose according to the wheel hub thickness. Common lengths are 28mm, 30mm, 35mm, and 40mm. Too long will protrude from the wheel hub and affect aesthetics, while too short will prevent the installation of valve caps and tire pressure monitoring devices.
3. Base diameter: Generally 11.5mm, it must fit tightly against the inner side of the wheel hub to ensure airtightness.

Common model equivalents

• TR413: Stem length 28mm, suitable for small passenger car wheel hubs.
• TR414: Stem length 30mm, suitable for most household car wheel hubs.
• TR415: Stem length 35mm, suitable for SUVs and MPVs with thicker wheel hubs.

2.Metal valve stem (for tubeless tires only, commonly known as "vacuum valve")

Suitable for tubeless tires, it offers superior durability and airtightness compared to rubber valve stems, and is commonly used in modified cars and high-performance vehicles.

Core dimensional parameters

1. Thread specifications: International standard V3.2×0.35 thread (thread outer diameter 3.2mm, pitch 0.35mm), compatible with tire pressure monitoring sensors (TPMS).
2. Shank length: Available in short (30–40mm), medium (40–60mm), and long (60–80mm) lengths, corresponding to different thicknesses of modified wheel hubs and off-road vehicle wheel hubs.
3. Installation hole requirements: The diameter of the hub mounting hole must be 11.3–11.6 mm; a larger diameter will lead to a loss of airtightness.

Selection notes: Metal valve stems require a dedicated rubber sealing gasket, and sealant should be applied during installation to enhance sealing performance.

Truck/Bus Large Valve Stems

These large-sized tires are suitable for heavy-duty trucks and buses, offering high load capacity and a more robust structure.

• Core dimensional parameters
  1. Shaft diameter: Commonly 12mm and 16mm, suitable for large-diameter hubs.
  2. Shaft length: Varies from 50–120mm, customized according to the hub and tire thickness.
  3. Interface specifications: Mostly large-diameter inflation interfaces, compatible with truck-specific inflation guns.
• Typical models: suitable for heavy-duty tires such as 12.00R20.

4. Motorcycle/bicycle valve stem

• Motorcycles: Commonly use TR4 type short valve stems, with a stem length of 15–25mm and a stem diameter of 8mm, suitable for small wheel hubs.
• Bicycles: Available with French valves (FV) and American valves (AV).
  • French valve: 4mm stem diameter, slender design, good airtightness, suitable for road bikes;
  • American-style valve stem: 8mm stem diameter, similar in structure to car tire valve stems, suitable for mountain bikes.

II. Key Steps in Selecting Valve Stems

1. Confirm the tire type: for tires with inner tubes, choose rubber valve stems; for tubeless tires, metal valve stems are preferred.
2. Measuring wheel hub parameters: Use calipers to measure the diameter of the wheel hub mounting hole and select a valve stem with a matching diameter; measure the wheel hub thickness to determine the required stem length.
3. Consider additional equipment: If installing a tire pressure monitoring system (TPMS), you will need to select metal valve stems with threads, and the stem length must allow sufficient space for sensor installation.。
4. Matching usage scenarios: Extended metal valve stems are recommended for off-road and heavy-duty vehicles; standard rubber valve stems are sufficient for regular passenger cars.

III. General Size Matching Table (Civilian Vehicles)

Vehicle Type	Recommended Valve Stem Type	Stem Diameter	Common Stem Length
Passenger Cars	TR Series Rubber/Metal Vacuum Valves	8mm	28–35mm
SUV/MPV	Metal Vacuum Valve	8mm	35–45mm
Light Trucks	TR Series Rubber Valve Stems	10mm	40–50mm
Motorcycles	TR4 Short Rubber Valve Stem	8mm	15–25mm