Nitrogen vs. air—which is better for your bike?

Line of parked motorcycles
December 11, 2018

Using nitrogen instead of plain old air to fill motorcycle tires is a topic of interest among many motorcycle riders. As nitrogen generators become more affordable, the use of nitrogen in tires will become more widespread. So why use nitrogen in motorcycle tires? Are the benefits worth the cost?

Nitrogen vs. air

We’ve been filling our tires with air since the beginning of pneumatic tires. Here’s what air is composed of:

  • 78% nitrogen

  • 21% oxygen

  • 1% water vapor and other trace gases

So, nitrogen is already in your tires when they are inflated with simple air. When filling tires primarily with nitrogen, the amount of nitrogen in them is increased to an average of 93%–95%.

Why use more nitrogen?

Let's talk about the science for a moment. The primary reason for using a higher concentration of nitrogen in our tires has to do with the size of its molecule. Nitrogen is a larger molecule than oxygen, the other main component in air. Tires on rims tend to lose pressure over time, and smaller molecules migrate out faster. That means tires filled with a higher concentration of nitrogen will maintain their pressure longer than tires inflated with air.

What’s wrong with using air?

The big negative with air is that it will contain 1% water vapor. Water vapor in a cold tire condenses into a liquid, reducing tire pressure. When the tire heats up during a ride, the liquid evaporates, increasing inflation pressure. Water and oxygen also cause corrosion.

Pros and cons of using nitrogen

Filling new tires with nitrogen adds to their replacement cost, but this should go down over time as the technology spreads. And since the cost of a nitrogen generator is several thousand dollars, we don't recommend purchasing a generator to use for yourself at home.

Remember, correct tire inflation is critical

Whether you use nitrogen or air, correct tire inflation is critical to maintaining the safe handling of your motorcycle. Proper inflation also results in better fuel economy and extends the life of your tires.

Tires should be checked before every ride. But checking tire pressure releases a small amount of gas from the tire, so daily pressure checks will require adding something back. Adding simple air to nitrogen-filled tires will reduce the percentage of nitrogen, but it’s better to have correct inflation with air rather than under-inflation with nitrogen.

So, is nitrogen worth the extra cost? The choice is yours. But correct tire inflation is priceless.

Till next time, ride safe!

The general information in this blog is for informational or entertainment purposes only. View our blog disclaimer.

*Data accuracy is subject to this article's publication date.

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