Road tubeless valves

How to choose road bike tubeless valves

A tubeless valve replaces the inner tube valve: it passes through the rim, is secured with a nut and seals against the rim with a conical gasket. It is a simple part, but there are three specifications that are easy to get wrong.

Length, determined by rim depth

• Allow for the rim depth plus 15 to 20 mm to leave enough valve exposed for easy inflation.
• 42 to 47 mm for a shallow rim, 55 to 60 mm for a 40 to 50 mm rim, 80 to 100 mm for a deep time-trial rim.
• If the valve is too short, it barely protrudes and the pump head cannot grip it. If it is too long, it wobbles and gets damaged.

Seal shape

The standard conical seal fits most rims. Some flat-bottomed or deep-channel rims need a specific seal, often supplied by the wheel manufacturer — Mavic UST, DT Swiss, Zipp and Enve offer valves matched to their rims. If the valve leaks despite being properly tightened, the seal almost always fails to fit the rim bed.

Standard flow or Big Bore

• Valves with large internal diameter — Muc-Off Big Bore, Peaty’s MK2 — let more air through at once, helping a stubborn tubeless tyre seat during fitting.
• They also make it easier to inject sealant and are less prone to clogging.
• On a narrow-channel rim, check that the valve hole accommodates the valve’s outside diameter.

The valve core and maintenance

Choose a valve with a removable valve core : this lets you inject sealant and clear the valve when latex has dried inside it. Keep a valve core tool in your saddle bag. Caps and fittings can be replaced individually — a seized core costs only a few euros to replace, so there is no need to throw away the whole valve.

To find out more: How to choose tubeless sealant

See also: Road bike tubeless conversion kits · Road bike valve extenders · Road tyres