What’s Up with Presta Valves?

If you’re relatively new to mountain biking and either recently purchased a new bike—or are considering a purchase—you’ve probably noticed that some bikes use a strange-looking, skinny valve on the tires. These are called Presta valves, and in many ways they are far superior to the old-style valves you probably remember from your childhood bike.

Presta vs Schrader

Schrader valves are the type you see on automobile tires. A Schrader valve is wider than a Presta valve and is wrapped in rubber all the way up to the threaded end. There’s a pin in the center that must be depressed to open the valve to add or release air. A spring in the valve’s core keeps it all sealed up tight. You may still find these types of valves on lower-end mountain bikes—especially those that are not tubeless-ready.

Presta valves are long and thin, tapering at the top. The valve is made almost completely of metal and not wrapped in rubber. These valves are threaded up and down their entire length and are secured to the bike wheel by ring-shaped nut. There is also a knurled nut at the top end of the valve that must be unscrewed to open the valve in order to add or release air. These valves are always found on road and high-performance bikes because they can hold much higher air pressures than Schrader valves. Presta valves are also common on mid to high-end mountain bikes—especially if those bikes are either tubeless-ready or set up tubeless by the factory.

Why Presta for Mountain Bikes?

So you’re probably asking yourself, “If Presta valves are made to hold higher pressures, but tubeless mountain bike tires can run lower pressures, why use a Presta valve at all?”

That’s actually a great question, and the answers are not obvious to those unfamiliar with the intricacies of Presta valves. Here’s a quick rundown of why Presta valves are great for mountain bikes:

• Easier Inflation: Unlike Schrader valves, Presta valves have no valve spring to overcome. This makes inflation with a floor or hand pump a cinch.
• Stronger Wheels: Because the Presta valve has a smaller diameter than a Schrader valve, the hole drilled into the wheel is smaller. This allows for narrow wheels to maintain sufficient strength.

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  Easy Maintenance: Almost all Presta valves on today’s tubeless setups have removable valve cores. This means when the core goes bad you can just swap out a new one. Additionally, if the entire valve goes bad, you can simply unscrew the nut on the valve shaft and replace the whole thing in minutes.
• Sealant Refresh: To refresh the sealant in a tubeless tire—without needing to unseat the tire from the bead—you can simply remove the valve core and inject new sealant.
• Fewer Sticky Valves: Because of the Presta valve’s design not including a valve spring, there’s less for your sealant to gum up.
• Multiple Stem Lengths: If you need or want a longer valve stem, Presta valves come in lengths from 32mm up to 60mm.

Not everyone out there loves Presta valves. One writer at Bike Radar thinks manufacturers should all move back to Schrader valves due to several factors—from the fragile nature of the thinner valves to the need for a different type of pump head.

What do you think about the advantages and disadvantages of Presta valves for mountain biking? We’d love to hear from you in the comments.

Have fun, ride smart, and keep shredding!

Image by Peter.shaman – Own work, CC BY-SA 4.0, Link