As it is an Arai helmet, you can take joy in the fact that safety and protection will have been in the front of the designers mind throughout all stages of development of this helmet. It is based on the old Quantum, but has a new outer shell that is longer front to back, giving the rider a lot more room around the chin. It has the same strengthening band as the RX-7 GP, but a completely new ventilation system. As most Arai helmets do, the Quantum ST has a removable and washable liner with an emegency cheek pad removal system.
Out of stock
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Arai Helmets
S / M / L
Circumference (cm)
XS
53 - 54
S
55 - 56
M
57 - 58
L
59 - 60
XL
61 - 62
2XL
63 - 64
How to Measure
To find the right helmet size, measure all the way round your head at the widest point. Keep the tape measure above your ears and make sure that the tape measure is not too tight, nor too loose. Take your measurement in centimeters (cm), not inches.
Checking for Best Fit
When a new helmet is first worn, it should actually be slightly tight, with the interior coming into contact with most of the head, but not so restrictive that it causes any pain. There should be no "hot spots" - places where the helmet's interior puts pressure on specific points of the skull or face - but it should not move around freely. With time, a helmet will adjust to match the shape of the rider's head as it is worn and goes through "break-in" and loosens up a little. However, it should never become loose enough to easily turn from side to side.
Put the helmet on - it should be a little tight as it goes on over the head
The helmet should sit on the head evenly with the eye port's upper edge sitting just above the eyebrows and have good peripheral vision available to see side-to-side
Try putting a finger between the helmet interior and the head. If it easily fits, a smaller size should be tried next. Note that some helmet models allow for the cheek pads to be changed out for better fitment, so consider this too when checking for proper sizing
The Arai Quantum ST is constructed using a Super cLc (complex laminate construction) shell, giving it the ultimate edge in safety and protection. It has new IQ side exhaust vents and a FFS (free flow system) guided air stream, giving the ST overall great ventilation allowing you to use the helmet in even the hottest of environments. The helmet comes with a Pinlock 100% Max Vision Insert that fits into a recessed visor, giving a fog-free view out of the entire aperture. It has a distinctive new Hyper Ridge reinforcement band and a unique single piece, multiple-density EPS foam liner allowing the helmet to have the highest level of shock absorption. The helmet is ECE 22-05 /SNELL M2010 approved too, so you know it is officially a very protective helmet and not just by word of mouth.
To find the right helmet size, measure all the way round your head at the widest point. Keep the tape measure above your ears and make sure that the tape measure is not too tight, nor too loose. Take your measurement in centimeters (cm), not inches.
Checking for Best Fit
When a new helmet is first worn, it should actually be slightly tight, with the interior coming into contact with most of the head, but not so restrictive that it causes any pain. There should be no "hot spots" - places where the helmet's interior puts pressure on specific points of the skull or face - but it should not move around freely. With time, a helmet will adjust to match the shape of the rider's head as it is worn and goes through "break-in" and loosens up a little. However, it should never become loose enough to easily turn from side to side.
Put the helmet on - it should be a little tight as it goes on over the head
The helmet should sit on the head evenly with the eye port's upper edge sitting just above the eyebrows and have good peripheral vision available to see side-to-side
Try putting a finger between the helmet interior and the head. If it easily fits, a smaller size should be tried next. Note that some helmet models allow for the cheek pads to be changed out for better fitment, so consider this too when checking for proper sizing
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