Just1 Motorcycle Helmet Size Guide
Not sure what size Just1 motorcycle helmet you need? Measure around your head just above your eyebrows, then compare your measurement with the Just1 helmet size chart below.
This guide covers Just1 motocross and off-road helmets, including the J22, J22F, J12, J18, J39 and J40 ranges.
Just1 Motorcycle Helmet Size Chart
| Helmet Size | Head Circumference |
|---|---|
| XS | 53–54 cm |
| S | 55–56 cm |
| M | 57–58 cm |
| L | 59–60 cm |
| XL | 61–62 cm |
| XXL / 2XL | 63 cm |
Please note: These are the general Just1 adult helmet measurements. The manufacturer's online chart sometimes lists Large as 58–60 cm, which overlaps Medium. If you measure 58 cm or fall between sizes, we recommend trying the helmet on before ordering. Not every Just1 model is manufactured in every size, and some versions may have different size limits.
How to Measure Your Head for a Just1 Helmet
You'll need a flexible tape measure. If you haven't got one, a piece of string and a ruler will do.
- Wrap the tape around the widest part of your head, just above your eyebrows and ears.
- Keep the tape level, making sure it passes around the widest part of the back of your head.
- Hold the tape comfortably snug without pulling it tight.
- Read your head circumference in centimetres and compare it with the Just1 size chart above.
It's worth measuring twice to make sure you've got it right.
How Should a Just1 Motorcycle Helmet Fit?
A Just1 helmet should feel snug and secure without causing painful pressure around your forehead or temples.
The internal padding should make even contact with your head, and the cheek pads should feel firm against your face without causing discomfort.
With the chin strap fastened, gently move the helmet from side to side and forwards and backwards. It should move with your head rather than sliding around independently.
Remember that helmet comfort padding can settle slightly with use. A helmet that's already loose when new is unlikely to get any better.
If you're between two sizes, try both wherever possible. The correct fit matters more than the letter on the label.
For further advice, read our guide to dealing with a tight motorcycle helmet.
Do Just1 J22, J39 and J40 Helmets Fit the Same?
The Just1 J22, J39 and J40 motocross helmets use the manufacturer's general adult head circumference measurements, but their different shell designs and internal padding can affect how they feel when worn.
The J22 is a carbon-fibre motocross helmet, while the J39 and J40 use thermoplastic-based shell construction. Each has its own internal design and padding arrangement.
Even if you've previously owned a Just1 helmet, don't assume another model will feel identical simply because it's the same letter size.
Motocross helmet fitting is particularly important when wearing goggles. Make sure the helmet sits securely and your goggles fit comfortably without creating pressure around your forehead.
Always try your chosen helmet on where possible.
Just1 Motorcycle Helmets at RaceLeathers
Looking for a Just1 motocross helmet? Browse our Just1 helmet range, including the J22, J39 and J40.
You can also explore our full selection of motorcycle helmets.
If you're unsure about sizing, visit RaceLeathers and we'll help you find a helmet that fits properly.
RaceLeathers
136 Bolton Road
Darwen, Lancashire
BB3 1BZ
Opening hours: Monday to Saturday, 10am–5pm.
The North West's leading bikers store based in Darwen, Lancashire is now home to an ever growing, vast array of motorcycle clothing and helmets to suit all budgets.
The North West's leading bikers store based in Darwen, Lancashire is now home to an ever growing, vast array of motorcycle clothing and helmets to suit all budgets.