Introducing FLO Air Gauge – Save Time with Tire Pressures

Rethinking the Pump – The FLO Air Gage

A couple years ago a good friend and fellow researcher, John Mercer, called me voicing a frustration he had recently ran into during transition at his race. John’s name may be familiar to you, he and his team at UNLV worked side by side with me for 18-months developing the on-road protocol for testing rolling resistance, which lead to proving that wider internal rim width is faster. During this deep dive into rolling resistance, we learned and expanded upon the importance of tire pressure and the concept of an “impedance break point”. An inaccurate read of tire pressure could cost you up to 6 minutes over an Ironman. John knew this and his frustration was that he had no way to accurately inflate his tires during transition without a hassle. A standard floor pump has a gage but with the exception of a few expensive ones, the gages are often inaccurate, plus they are difficult to transport. Mini pumps travel well but have no gage. This is why we developed the FLO Air Gage. 

The Innovation of The FLO Air Gage – Modular Inflation

The FLO Air Gage is an accurate gage that connects to any pump. The FLO Air Gage connects inline with a mini pump, providing a gage to set your pressure. It also connects to a floor pump so you can bypass the floor pump gage and assure better accuracy. Having the ability to connect to multiple different pumps introduces a new category we are calling “modular inflation.”

An Education on Pressure Gages

If you think about pumps, the most important part is the gage. Interestingly, the number you read can be misleading. A gage has an accuracy known as a “Percent of Span.” Span is the total range of the gage, for example, 0-300 psi. To determine how much your gage can vary, multiply the percent of span by the span, or total range. Let’s look at an example from a standard floor pump:

1. A gage with a 3% accuracy of span with a 300psi has an accuracy of +/- 9psi. This means that if your gage reads 80psi with a +/- 9psi accuracy, your tire pressure can be anywhere from 71psi to 89psi. 

As you can see, tire pressures can vary vastly from what the gage reads. As a cyclist, it’s problematic to have such a large range which can cost you speed and time. 

Why Does Accurate Tire Pressure Even Matter?

Our on-road rolling resistance testing taught us a lot about speed, tire pressure, and the impedance break point. We know that the higher your rolling resistance, the slower you go. Up to the impedance break point, change in rolling resistance decreases slowly as you increase tire pressure. Once the tire pressure surpasses the impedance break point, your rolling resistance spikes drastically. Therefore, having a tire pressure that is too high is much worse than having a tire pressure that is too low. The effect is asymmetric. The graph below shows how quickly rolling resistance can change. 

Most importantly, the rule of thumb is that for every 1 psi your tire pressure is over the impedance break point, you lose 1 watt. So, if your tire pressure is reading 80psi but your actual tire pressure is 89psi, you are giving up 9 watts! That is a big deal to any competitive cyclist.

A New Standard for Accuracy

We designed the new FLO Air Gage to have a 1% percent of span accuracy with a span of 120psi. Therefore, your tire pressure is guaranteed to be +/- 1.2psi of what you’re reading on the gage. For the same 80 psi read, your pressure will be between 78.8psi and 81.2psi. The modular design of the FLO Air Gage brings this accuracy to your home, your training ride, and especially, your race. 

This brings us to the design parameters and innovations of the FLO Air Gage.

The Design Parameters

We can’t say it enough- accurate tire pressure matters. So how can we design something with great accuracy that is also transportable so you can use it anywhere? (Note: this article details the FLO Air Gage but other new products are also mentioned. We will have follow-up articles detailing those, too.) The following were our design parameters:

1. An accurate, affordable, reliable, and rugged gage that reflects a span of cycling pressures
2. Works with any Presta pump 
3. Ability to bleed pressure
4. Effective and reliable connection to a wheel
5. Quick pump head removal to limit air loss
6. Compact for travel 
7. Durable and replaceable parts 
8. Affordable as a system 

The Gage – Accurate, Affordable, Reliable, and Rugged With a Span for Cycling

We partnered with Ashcroft for the gage. Ashcroft is arguably the best gage manufacturer in the world and manufactures their gages in the USA. 

For accuracy, we lowered the percent of span to 1% and we had a custom span design with a max pressure of 120psi, which covers 99% of all cycling applications. You will never be more than +/- 1.2 psi on any reading you see on the FLO Air Gage.

For reliability, we chose an analog gage vs. a digital gage. An analog gage works all the time. No early morning transitions with a dead battery. Plus, it is also more affordable. A digital gage with the same accuracy was more than 8x the price of the analog gage.

Finally, to keep the FLO Air Gage safe as you travel the world riding and racing, we covered the gage with a rubber boot. 

Versatile – Works with any Presta Pump 

The vision was for the FLO Air Gage to be versatile and to have the ability to with any standard Presta pump. We created a custom Presta-to-hose fitting that accepts any removable core valve extender allowing for easy connection to any Presta pump. It’s also easily serviceable Should the valve get damaged. 

Precise – Ability to Bleed Air Pressure

In our experience, and what we use for testing on-road and in the wind tunnel, the most precise way to set an accurate pressure is by over inflating the tire and bleeding air until you hit your target pressure. Once the pump is removed from the FLO Air Gage the removable core valve acts as a bleed valve. 

To hit your desired pressure: over inflate the tire, remove the pump from the Presta valve, then bleed the pressure while watching the pressure on the FLO Air Gage. Removal key points in the next section. 

Effective and Reliable Connection to a Wheel & Quick Pump Head Removal

We looked at number of pump heads for the FLO Air Gage and to be honest, most were really terrible. Here is what we found: 

1. Plastic pump heads are cheap and break easily and are prone to leaking. 
2. Aluminum chucks normally do not lock and are a complete pain to use. 
3. Lever locking Presta chucks either do not have the ability to fine tune the connection, are expensive, or are difficult to remove without air loss.

So what did we do? We designed a new locking chuck from the ground up. The FLO Locking Chuck will ship with all FLO Air Gages.  The FLO Locking Chuck is also available to purchase separately for existing pumps. You can read a more in depth article on the FLO Locking Chuck here but a summary of the FLO Locking Chuck features are below:

1. The FLO Locking Chuck is made from steel and rubber. 
2. Seals to any Presta valve or extender with a dial locking mechanism. Unlike a one-size-fits- all lever, you adjust the dial to your desired closure. 
3. Costs less than $50. 
4. A two finger grip that allows for a quick, straight, and clean pull removal. No more wiggle removal—wiggling a chuck creates air loss. 
5. A Schrader connection for versatility.  The FLO Locking Chuck can be added to any pump that has a Schrader connection.

Compact for Travel

The FLO Air Gage packs into one small case. The dimensions are in the range of 9in x 7in. We plan to include a travel bag for the FLO Air Gage.

Durable and Replaceable Parts

All parts are made from durable material and free from plastic. Each part is also 100% replaceable. All parts listed below: 

1. FLO/Ashcroft Gage w/ Boot
2. Brass Tee
3. Brass Hose Barbs
4. Continental Hose
5. Hose Clamps
6. Aluminum Presta to Hose Barb
7. Aluminum Schrader to Hose Barb
8. Aluminum Presta Valve w/ Removable Valve Core
9. FLO Locking Chuck

Pricing & Release Date

The FLO Air Gage is $199 and includes all parts mentioned above, including the FLO Locking Chuck. The FLO Air Gage is available for pre-order now and is expected to ship late April/early May 2023. This is a limited production run, so if your are interested, pre-order today!  

What About a Pump?

You may be wondering why we haven’t mentioned a pump product? Stay tuned! We have another exciting modular inflation product announcement coming soon.