Bicycle inner tube valves come in different types and lengths, to fit the variety of bicycle rim designs on the market. If your valve is too short, you may not be able to add air. Too long and you risk damaging the stem.
VALVE TYPES
SCHRADER
Found on cars and lower-priced bikes. Its larger diameter (8mm) means it won’t fit through the valve hole on rims drilled for Presta.
PRESTA
Skinnier (6mm), with a barrel nut on top to hold the valve closed (see Fig. 1). Loosen the nut to add air, and be sure to re-tighten. Presta valves do fit in Schrader holes, but the loose fit increases risk of inner tube failure.
VALVE LENGTH PARAMETERS
Rule #1
Presta “Valve Length” refers to the distance from the base of the STEM to the top of the VALVE NUT when it’s full tightened (see fig. 1). Schrader valve length is measured from the base to the top edge of the threaded section, without the plastic cap.
RULE #2
At least 15mm of Presta valve STEM should be showing, to allow the attachment of a variety of pumps and CO2 inflators (you may not always be able to use your own!). For Schrader valves, a minimum of 12mm should be showing.
A valve that is excessively long for your rim not only adds weight and affects aerodynamics, but also leaves the stem more vulnerable to damage from a side load (mini pump, tree branch, etc.).
RULE #3
Fig. 1: A 48mm Presta Valve (the “stem” is shown in gold)
DIALING IN YOUR PERSONAL VALVE LENGTH
Step #1: Determine Your Rim Height
Measure from the outer edge of the rim (where the tire disappears inside), to the spoke face (where the spokes emerge, see Fig. 2). This does not need to be ultra precise, and there is no need to take off the tire.
Step #2: Calculate
For Schrader
All Biketube Brand Schrader valves are 35mm long. These will fit all rim heights UP TO 33MM.
For Presta
A formula, as a general rule:
RIM HEIGHT + 10MM to 30MM = SAFE VALVE LENGTH.
At Biketube Brand we typically offer 48mm, 60mm and 80mm Presta valves.
Fig. 2
Use this handy table to determine your Biketube Brand Presta length:
TIPS AND TRICKS
ENVE Composites make some of the best wheels on earth.
We collaborated with them on their line of inner tubes and tubesocks.
If you’re using deep section carbon wheels, you might hear the valve stem rattling against the rim. We co-developed this anti-rattle sticker with Enve. If you’d like receive some with your order free of charge, just send us an email.
