The bicycle was invented in 1817, and inflatable rubber tires followed suit. After so long, you’d think we’d have figured out what to fill those tires with.
Or have we?
These days, helium has become a hot topic in the cycling community. And while we can’t tell you why—probably some YouTube video that went viral—we can definitely tell you whether or not this gas is all it’s cracked up to be.
While helium is lighter than air and technically saves on weight, helium atoms are tiny and escape from porous rubber quickly, causing your tires to lose inner pressure go flat much more quickly.
Let’s take a look at the misconceptions people have about helium and why it’s better to leave it for children’s balloons and stick with good old air for your bike tires.
Why Do People Think Helium Works?
Helium is lighter than air, right? Everyone knows that.
Balloons float because they’re filled with helium. Therefore, bike tires are lighter when you fill them with helium.
The common understanding of helium and its properties leads people to assume that helium is a *better* solution than air when it comes to what to fill your bike tires with.
Some also incorrectly assume that race car drivers use helium to shave off a bit of weight. But they really use nitrogen (N2) in their tires.
The potential of shedding a few grams of weight (and reducing the muscular energy needed to propel the bike forward) tempts people into thinking that helium is a great biking hack to improve roll and boost performance.
Unfortunately, it’s not as simple as that.
While it is technically true that your bike will be lighter with helium tires, the difference isn’t as much as you might think—and your bike definitely won’t fly faster.
Regardless of whether you’re using a mixture of helium and air or just pure helium, it’s not likely that you’re saving more than twenty grams of weight, which really isn’t worth all the downsides, even for a professional racer.
The Size of Helium Molecules Causes Leaks
So just what exactly does happen if you put helium in your bike tires?
Well, the biggest problem with helium when used in bike tires is that helium is one of the smallest elements with regard to atom size.
As such, the biggest problem with using helium in your tires is that it will make its way through the rubber, causing your bike to deflate much more quickly. Air, on the other hand, doesn’t work its way out of the rubber as quickly, so your tires will stay filled much longer.
This is even more true for race bikes, which often use clinchers and tubulars with latex tubes. An inner tube made of latex, a more porous material than butyl rubber, would deflate in no time if filled with helium.
Helium Is Expensive to Use in Bike Tires
Another big reason why you shouldn’t use helium in your bike tires is that it is expensive. Due to that annoying particle size, helium will eventually leak from any solid container it’s stored in.
The inability to store it well hikes the price up. In addition, it’s relatively scarce and better used for other things.
As such, you’d be spending a pretty penny just to put this precious gas in your bike for not much return. You’re using more of it because it leaks, and you’re paying for the privilege.
Moreover, when you’re pumping your bike, you have to pump even longer just to fill the same amount of space.
Honestly, when it comes to picking out an ideal substance to fill your bike tires with, you can’t get much better than plain old air (which comes at the very low cost of free anyway).
Constant Refills With Helium
Due to the nature of helium and how quickly it can go through rubber, you will be spending a lot more time pumping up your tires than you would normally, making helium extremely impractical for long rides (and group rides).
Underinflated tires are an issue, especially on the road, and helium tires don’t offer much in the way of longevity when it comes to maintaining a good PSI. The more your tires need refilling, the less time you’re spending out enjoying life on a bike.
Adding Air to Helium-Filled Tires
Naturally, people wonder: can you add air to helium filled tires?
The answer to this question hearkens back to the earlier topic about the nature of helium.
Helium is a completely inert gas and poses no risk compared to oxygen, but the smaller atom size means that if you fill part helium and part air, you will still end up underinflating your tires because you need more helium than you do air to hold a sustainable PSI.
The issue of diffusion, whereby the helium will leak out of the tires, still persists with a helium/air mix. So yes, you certainly can add air to tires filled with helium, but a 100% air fill is still the better option for biking.
It’s easy to understand how helium got wrapped up in the debate of what’s best to fill your tires with. It’s light, and on paper, less weight means more speed. Unfortunately, helium just doesn’t work well with bike tires.
On top of offering little to no benefits helium will leak from your tires much faster than air will, making you have to constantly refill. These refills aren’t cheap either. Helium’s leaky nature makes it hard to contain and thus very expensive.
Underinflated tires are a major cause of bike accidents, so when to comes to choosing what to fill your bike tires with, you can’t get much better than good, fresh air.