Arai Quantum–X Test: High-End Street Helmet

Taking cues from Arai’s flagship Corsair-X motorcycle racing helmet, the Quantum-X is a street-oriented helmet designed to be a little quieter and a little plusher.

A round-oval head-shape design, the Arai Quantum-X is a sibling to the long-oval Signet-X, giving you a choice for head fitment. In practice, there is not a huge difference and, indeed, I can wear both all day without discomfort. However, the round-oval Quantum-X is preferable for me. Other than fit, the two helmets are essentially the same, and for our purposes here, my comments apply equally to both models.Arai on KTM

When talking comfort, the Quantum-X is a typical Arai. That’s to say it has a luxurious feel when the helmet is on. The fit is firm at the two crucial contact points—across the crown of the head to the forehead, and the cheek pads. Although the helmet feels snug, it is absolutely, perfectly comfortable on my head and I can easily wear the helmet all day. Always make sure you get a professional fitment when purchasing a helmet.

The precision of an Arai fit ensures that I never get a hot-spot at the front across my forehead. An Arai is like an expensive pair of Italian shoes—all shoes of the same size are not created equal—and neither are helmets; Arai puts all of its considerable experience into the subtle nuances that ensure a precise fit. Apart from the aforementioned different head shapes, Arai also sells different cheek pad thicknesses. Although if the fit is very close, removing one or two of the thin foam layers from inside each cheek pad can easily be done to customize the fit to your face.

The ear cutouts are well designed, too, so that my ears are never crushed. The EPS layer has deep indentations that allow ample room for headset speakers. With my usual Sena headset installed, my ears aren’t irritated or chafed.Arai Helmet test

This level of fitment is not to be underestimated. Correct sizing also ensures that the helmet doesn’t rotate forwards, especially if the chinstrap tightly cinched. All day comfort is vital, but fit also affects the level of wind noise inside the helmet. Of course, this is a personal variable that depends on multiple factors, but for me, the Arai Quantum-X is as quiet as any, and quieter than most.

Although chinstraps are rarely mentioned, this is another area where Arai’s experience comes into play. It is vital that the chinstrap mounting points are precisely placed so the chinstrap doesn’t angle backward and start to strangle you, or pull forwards and make the helmet roll across the top of your eyebrows. Arai chinstraps are always perfectly placed, so the strap holds the helmet on securely, but doesn’t chafe or pull the helmet in an awkward direction against your neck.

Arai interiors are exceptionally well made, again by hand. The interior padding is easily removable so that it can be washed; it is almost as easy to put back as well. The cheek pads have orange tabs so that emergency personnel can remove the cheek pads if necessary, and then safely remove your helmet without adding pressure to your neck.Arai Quantum-X Motorcycle Helmet Test

Obviously, the critical part of any helmet is the shell. Thankfully, the Arai shell has remained relatively unchanged for the last few years, and it still maintains that smooth curve with a constant radius of 75mm. According to Arai, this is optimum for the maximum dispersal of kinetic energy in the event of an impact. The Quantum-X shell shape is also aerodynamic, and I find the Quantum-X stays comfortably in place even at high speed with no lifting, shuddering or twisting that can be so fatiguing with some other helmets.

Arai has gone to a lot of effort to keep the outside of the shell smooth, with no protuberances or awkward angles that might snag and wrench your neck if you’re unfortunate enough to be sliding along with your head banging on the ground. Yes, I have been in this situation on four different occasions wearing an Arai motorcycle helmet, and each time I have wholly appreciated the level of technology and skill that goes into the helmet’s safety, as well as its comfort.

Arai shells feature its proprietary Peripherally Belted-Super Complex Laminate Construction (PB-SCLC), where woven fiberglass belts reinforce the shell at critical points without adding extra bulk to the outside or overall weight. The belt that runs around the bottom of the helmet reinforces the rim, allowing Arai to have a bigger opening in which to put your head. This ensures the helmet is easier to put on and take off, and I never feel as though I’m in danger of ripping my ears off when I’m doing either one. This, in turn, helps the helmet be snug without feeling claustrophobic.Arai on Suzuki

Another benefit of PB-SCLC is the large, wide eyeport. The opening is wide enough that the helmet doesn’t interfere with my peripheral vision, and tall enough that, when in a fairly aggressive racing crouch, the forehead of the shell doesn’t interfere with my forward view.

Venting on the Quantum-X is outstanding, and the rear vents create a low-pressure area that pulls air through the front vents and across the inside crown of the helmet. The venting is so efficient that on one particularly chilly morning, I had to close the vents as the top of my head was getting cold. The mouth vent also works very noticeably, and the eyebrow vents mitigate faceshield fogging.Arai Quantum-X

The final part of any helmet equation for me is the faceshield. Arai scores mixed marks in that department. The faceshield is exemplary. It is optically perfect, so there are no weird visual distortions around the sides, and I don’t arrive at my destination with the headache that I’ve occasionally experienced with some other helmet brands. Additionally, the Arai Quantum-X includes the latest Pinlock-120 lens for those who ride in humid conditions.

However, the quirky Arai fitment mechanism that was so controversial in the past has now been replaced with a new-but-still-quirky faceshield replacement mechanism. It is in some ways easier to use, and in other ways more complicated. Fortunately, the Arai faceshield is also hard-wearing, so if you look after it, you won’t need to change it very frequently.Arai Quantum-X Test

The Quantum-X graphics and paint finish are up to Arai’s usual pre-eminent standard, and the choices are excellent. I’m delighted with the new Cliff Red/Black graphic and its superb matte paint finish.

Overall, the Arai Quantum-X is an expensive investment. It is a handmade in Japan, ultimately evolved, highly sophisticated piece of technical equipment with Snell M2015 certification. Incredible attention over several decades has been paid to every tiny part of the minutiae that makes up this Arai helmet. If you never have an accident, then you will still be delighted with the comfort, fit, and finish of the Arai Quantum-X. However, if you are unlucky enough to bang your head hard, then like me, you’ll be very relieved you invested in an Arai.

Arai Quantum-X Fast Facts
Sizes: XS-XXL
Colors: 7 solids; 9 graphics
Arai Quantum-X Prices: Solids from $680 MSRP; graphics, $830 MSRP