We all want to go fast. So do our bikes. But if you’re racing against the clock over changing terrain or riding fast for fun, your tire pressure could be keeping you from even higher speeds.
We all want to go fast. So do our bikes. But if you’re racing against the clock over changing terrain or riding fast for fun, your tire pressure could be keeping you from even higher speeds.
One Tire Pressure Doesn’t Work
Considering how much time we spend planning our rides or thinking about the next one when it comes to tire pressure, oftentimes, it feels like anything will do. If your pre-ride routine involves giving your tires a quick squeeze and calling it good, then you’re leaving a lot of speed on the table. And we haven’t even spoken about comfort, safety, or the thought that your tire pressure should change as you ride.
Pumps: Not a Good Gauge of Pressure
Maybe we don’t spend much time on our tire pressure because inflating our tires always feels like a best guess. If you’ve ever wondered if your pump gauge is telling you the truth, then there’s a very good reason (amongst many) to explore the Gravaa system.
Install a Gravaa wheelset on your bike, and you can forget your pump altogether. All you have to do is ride, and your tires will reach your preset pressure on their own automatically, reliably and accurately. Even if they’re soft from spinning wheels in the shed/garage/living room, they’ll be at the proper pressure after only a few meters.
But that’s just the start.
Pumps: Not a Good Gauge of Pressure
Maybe we don’t spend much time on our tire pressure because inflating our tires always feels like a best guess. If you’ve ever wondered if your pump gauge is telling you the truth, then there’s a very good reason (amongst many) to explore the Gravaa system.
Install a Gravaa wheelset on your bike, and you can forget your pump altogether. All you have to do is ride, and your tires will reach your preset pressure on their own automatically, reliably and accurately. Even if they’re soft from spinning wheels in the shed/garage/living room, they’ll be at the proper pressure after only a few meters.
But that’s just the start.
Gravaa is Faster
Starting your ride certain of the pressure of your tires and confident that they’ll always be at your preset pressure is one thing. Changing your pressure in real-time as you ride is another..
Before we get to that, let’s take a look at why you would want to change your tire pressure during your ride. There are many reasons. The biggest is speed. As our tests have proven, over changing terrain, particularly where the way ahead gets bumpy, having the ability to – in this instance – lower your tire pressure has a positive impact on rolling resistance, allowing you to expend less energy to maintain the same speed. Or, to put it another way, faster for less effort.
And the reverse is also true. While lowering your tire pressure on rough terrain is a good idea, raising it when you return to smoother trails or roads will help maintain optimal rolling resistance. Ride and repeat this cycle over a race or your regular route, and based on the data from our own testing, you’ll be faster.
Gravaa is Faster
Starting your ride certain of the pressure of your tires and confident that they’ll always be at your preset pressure is one thing. Changing your pressure in real-time as you ride is another..
Before we get to that, let’s take a look at why you would want to change your tire pressure during your ride. There are many reasons. The biggest is speed. As our tests have proven, over changing terrain, particularly where the way ahead gets bumpy, having the ability to – in this instance – lower your tire pressure has a positive impact on rolling resistance, allowing you to expend less energy to maintain the same speed. Or, to put it another way, faster for less effort.
And the reverse is also true. While lowering your tire pressure on rough terrain is a good idea, raising it when you return to smoother trails or roads will help maintain optimal rolling resistance. Ride and repeat this cycle over a race or your regular route, and based on the data from our own testing, you’ll be faster.
Testing Gravaa
We’re Dutch, so where did we go to test Gravaa? To the cobbles, of course. We took our Cervélo Aspero 5 equipped with Gravaa x Reserve 42I49 wheels, Challenge Grifo Pro 29×1.30” (33-622) tires, a Favero Assioma DUO Power Meter (both pedals) and a Garmin Edge 830.
Our plan was to ride over three distinct sections of terrain: rough cobblestones (500m), smooth tarmac (1400m), and sand (1000m). Our 75kg test cyclist would ride them in both directions over multiple test days in mild weather (no rain, wind <2Bft).
During the tests, we measured elapsed time, distance, speed, power, and tire pressure in the front and rear tires. In all cases, we kept a constant offset of 0.2 bar between the rear and front tires. i.e., a tyre pressure of 3.5 bar means 3.5 bar at the front and 3.7 bar at the rear tire.
Testing Gravaa
We’re Dutch, so where did we go to test Gravaa? To the cobbles, of course. We took our Cervélo Aspero 5 equipped with Gravaa x Reserve 42I49 wheels, Challenge Grifo Pro 29×1.30” (33-622) tires, a Favero Assioma DUO Power Meter (both pedals) and a Garmin Edge 830.
Our plan was to ride over three distinct sections of terrain: rough cobblestones (500m), smooth tarmac (1400m), and sand (1000m). Our 75kg test cyclist would ride them in both directions over multiple test days in mild weather (no rain, wind <2Bft).
During the tests, we measured elapsed time, distance, speed, power, and tire pressure in the front and rear tires. In all cases, we kept a constant offset of 0.2 bar between the rear and front tires. i.e., a tyre pressure of 3.5 bar means 3.5 bar at the front and 3.7 bar at the rear tire.
Benchmarking
To establish the correct controls, we undertook repetitive tests on a smooth tarmac section, cycling in both directions to negate the effect of wind direction. We rode at different speeds and with a tire pressure of 3.5bar. We gathered information about aerodynamic drag from this data to isolate this effect from further measurements.
Smooth Tarmac
Later in the tests, we lowered the tire pressure on tarmac (also testing 2.5 bar and 1.5 bar). All tests were repeated multiple times on the same section – riding in both ways, like before, to subtract aerodynamic drag and determine the rolling resistance.
There are a few things to note from the results. For example, riding at 25 km/h with 1.5 bar required 12 more watts of power (in total) compared to 3.5 bar tire pressure.
Cobblestones and Sand
When it came time to test Gravaa off-road, we took to the rough cobblestone section and compact sand track. Like the tarmac tests, we rode these surfaces in both directions, with different speeds and different tire pressures. The table below summarizes the results at 25 km/h, from which we can observe that:
Lowering tire pressure from 3.5 to 2.0 bar on cobblestones will give a benefit of 32 watts. On compact sand, the gain is (going from 2.5 to 1.1 bar) 49 watts.
Of course, these results are valid under the test conditions we created. Nevertheless, the impact of tire pressure is significant.
What We Learned: Adaptable Tire Pressure is Free* Speed
Ok, it’s not free. When Gravaa is active and inflating your tires at 25 km/h, it consumes 4 watts per pump – a power loss of 8 watts. When inactive, there’s no power loss. Nor is there a loss when deflating your tires.
What You Gain
The test results above show significant differences. Gravaa gives you up to 10 extra watts on smooth surfaces (depending on the tire type, speed, weight and more). On non-smooth surfaces like cobblestone roads and compact sand tracks, Gravaa grants you a lot more power – up to 50 watts.
More than Performance
There’s a lot more to Gravaa than elevated performance. As a monitoring system, it keeps your tires at constant preset pressure – including if you puncture. Gravaa will pick up the pressure if your sealant does its job, returning you to your preset pressure in three seconds or less. And if you think that’s good, ask Marianne Vos, who suffered a potentially catastrophic puncture at the 2024 Gravel World Championships before Gravaa intervened, pumping her tires up and getting her over the line to take the win.
Riding with adaptable tire pressure is also safer and more comfortable. The list goes on. But we’ve gone on long enough.
Questions? Drop us a line.
What We Learned: Adaptable Tire Pressure is Free* Speed
Ok, it’s not free. When Gravaa is active and inflating your tires at 25 km/h, it consumes 4 watts per pump – a power loss of 8 watts. When inactive, there’s no power loss. Nor is there a loss when deflating your tires.
What You Gain
The test results above show significant differences. Gravaa gives you up to 10 extra watts on smooth surfaces (depending on the tire type, speed, weight and more). On non-smooth surfaces like cobblestone roads and compact sand tracks, Gravaa grants you a lot more power – up to 50 watts.
More than Performance
There’s a lot more to Gravaa than elevated performance. As a monitoring system, it keeps your tires at constant preset pressure – including if you puncture. Gravaa will pick up the pressure if your sealant does its job, returning you to your preset pressure in three seconds or less. And if you think that’s good, ask Marianne Vos, who suffered a potentially catastrophic puncture at the 2024 Gravel World Championships before Gravaa intervened, pumping her tires up and getting her over the line to take the win.
Riding with adaptable tire pressure is also safer and more comfortable. The list goes on. But we’ve gone on long enough.
Questions? Drop us a line.
