Circuit Evo 2 White-OMPSC0-0616-A01-020-GSM Performance OMP Circuit Evo 2 Helmet - White £86.73 (No Tax)
Bell KC7-EV CMR Kart Helmet 2-Edited-GSM Performance Bell KC7-EV CMS Kart Helmet £398.00 (No Tax)

Stilo ST5 CMR Carbon Kart Helmet

£689.00 (No Tax)

Snell-FIA CMR 2016-approved helmet. Measure above your eyebrows, match the centimetres, and call us if you sit between sizes.

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Size/Fitting guide
SKU: SLOAA0722AH1P5 Category:
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The ST5 CMR Carbon is the carbon fibre version of Stilo’s karting helmet, approved to Snell CMR 2016, which is the international standard for junior circuit karting. Part number SLOAA0722AH1P5. Stilo manufacture this helmet entirely in Italy, and the shell is built using the PURO process: the carbon weave carries its own finish without an external clear coat, keeping weight down while maintaining the structural integrity the homologation requires. Starting weight is from 1,040g.

Weight saving at this end of motorsport matters proportionally more than in circuit cars. A junior driver’s neck muscles are still developing, helmet weight represents a larger fraction of head mass, and the lateral loading through a kart’s cornering is sustained without the rest periods a circuit car with runoff provides. The difference between a fibreglass helmet and this carbon version, across a full race or a championship season, is measurable in fatigue levels.

There are no HANS posts and no radio connection. Kart helmets are homologated under a separate standard and neither is expected or required. The absence of intercom components allows the interior to be sized precisely against the driver’s head without any protrusion affecting fit. EPS cheek pads handle lateral impact protection and the 3mm clear visor includes a central two-position clasp that allows a slightly open locked position for lower-speed use.

The interior lining colour is chosen at ordering from seven options: Black, Blue, Red, Green, Neon Yellow, Orange, and Pink. The shell is carbon regardless of lining choice. Sizes run from XS at 54cm to L at 59cm, covering the head sizes relevant for junior karting competition.

Call or email us and we’ll check the lead time and availability for your size before ordering.

Additional information

Approval

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Colour

Communication

Interior Lining Colour

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HANS Posts

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Karting helmet size guide

Kart helmet sizing is model by model rather than brand by brand. Sparco alone run six different ladders across their kart range, and none of them matches their car helmet ladder. The good news is that every size on this site carries the head measurement inside the size name, so you can ignore the letter completely.

Read the number, not the letterOur size options are written like “M (57cm-58cm)”. Measure your head once and pick the option whose centimetre range contains your number. That is all you need to do, and it works across every brand and model on the site.

Measure the head

1One inch above the eyebrowsThen round the widest part at the back. Soft tape, level all the way round.
2Take the largest readingMeasure three or four times and use the biggest number you get.
3Hair as you driveMeasure with the hair down or tied as it will be under the helmet.
4Children grow, helmets do notBuy to the measurement today. A helmet bought big to last two seasons moves on the head, and you will be replacing it anyway when it is outgrown.

The homologation decides how big the helmet goes

This is the thing that catches parents out. Snell-FIA CMR is the junior standard and every CMR helmet we stock stops at around 59 cm, because it is designed for a child. If your driver measures more than that, a CMR helmet does not exist in their size and you need a CMS, a Snell K or an FIA 8878 helmet instead. Check which your series accepts before you shop.

Helmet Homologation Size range
Snell-FIA CMR 2016, the junior standard
Bell KC7-CMR Snell-FIA CMR 2016 54 – 59 cm
Bell KC7-EV CMR Snell-FIA CMR 2016 51 – 59 cm
Stilo ST5 CMR Snell-FIA CMR 2016 54 – 59 cm
Stilo ST6 CMR Zero and Lite Snell-FIA CMR 2016 53 – 59 cm
Sparco Stealth CMR Snell-FIA CMR 2016 53 – 59 cm
Sparco GP KF-4W CMR Snell-FIA CMR 2016 54 – 59 cm
Arai CK-6 Snell-FIA CMR 2016 51 – 60 cm
Stilo ST5F N KRT Snell-FIA CMR 2016 54 – 64 cm
Snell-FIA CMS 2016, the same shell for seniors
Bell KC7-EV CMS Snell-FIA CMS 2016 51 – 59 cm
Bell Carbon KC7-CMR Snell-FIA CMS 2016 52 – 59 cm
Senior kart standards
Stilo ST6 KRT FIA 8878-2024, Snell K2025 54 – 64 cm
Bell RS7-K Snell K2020 54 – 61 cm
OMP GP-R K Snell K2020 52 – 63 cm
Arai SK-6 Snell K2015 53 – 62 cm
Sparco Air KF-7W, Sky KF-5W Snell K2015 53 – 62 cm
ECE 22-06, practice and arrive-and-drive
Sparco X-Pro ECE 22-06 53 – 63 cm
Sparco Club X1 ECE 54 – 65 cm
OMP Circuit Evo 2 ECE 22-06 53 – 61 cm

ECE 22-06 helmets are road motorcycle homologated. They are popular for practice, arrive-and-drive and indoor karting, and they cover the widest size range, but most competition series will not accept them. Check your regulations first.

Ladders by brand

All measurements are head circumference in centimetres.

BellNumeric on most kart models. Pick your measured size.▼
Model Sizes
KC7-CMR 54, 55, 56, 57, 58, 59
KC7-EV CMR and CMS 51, 52, 53, 54, 55, 56, 57, 58, 59
Carbon KC7-CMR 52, 53, 54, 55, 56, 57, 58, 59
RS7-K Carbon 54, 55, 56, 57, 58, 59, 60, 61
RS7-K S 57-58, M 58-59, L 60-61, XL 61 to 61+
StiloLettered, and the ST6 KRT offers two different L liners.▼
Model Sizes
ST5 CMR XS 54, S 55, M 57, L 59
ST5 CMR Carbon XS 54, S 55-56, M 57, L 59
ST6 CMR Zero and Lite XXS 53, XS 54, S 55, S 56, M 57, L 59
ST6 KRT XS 54, S 55, M 57, L 58, L 59, XL 61, XXL 63, XXXL 64
ST5F N KRT XS 54, S 55, M 57, L 59, XL 61, XXL 63, XXXL 64

Stilo state their helmets run slightly smaller than other brands, so if you are on a boundary go up. The ST6 KRT lists an L at 58 cm and an L at 59 cm; those are two liner thicknesses in the same shell.

SparcoSix different ladders. Read the centimetres in the size name.▼
Model Sizes
Stealth CMR XS 53-54, S 55-56, M 57-58, L 59
GP KF-4W CMR XS 54-55, S 56, M 57-58, L 59
Air KF-7W, Sky KF-5W XS 53-54, S 55-56, M 57-58, ML 59, L 60, XL 61, XXL 62
X-Pro S 55-56, M 57-58, L 60, XL 61, XXL 62
X-Pro Gulf and Martini XS 53-54, S 55, M 56-57, L 58-59, XL 60-61, XXL 62-63
Club X1 Carbon XS 54-55, S 56-57, M 58-59, L 60-61, XL 62-63, XXL 64-65

None of these matches Sparco’s car helmet ladder, and several do not match each other. A Sparco kart M can be 56-57, 57-58 or 58-59 cm depending on which model you are looking at.

OMP and AraiBoth use the same ladders as their car helmets.▼
Model Sizes
OMP GP-R K XXS 52-53, XS 54-55, S 56-57, M 58-59, L 60-61, XL 62-63
OMP Circuit Evo 2 XS 53-54, S 55-56, M 57-58, L 59, XL 60, XXL 61
Arai CK-6 XXS 51-52, XS 53-54, S 55-56, M 57-58, L 59-60
Arai SK-6 XS 53-54, S 55-56, M 57-58, L 59-60, XL 61-62

How it should fit

Snug enough that it is slightly awkward to pull on, with the cheek pads pressing the cheeks up. With the strap done up you should not be able to rotate the helmet forwards off the head. The lining beds in over the first few sessions, so a helmet that feels merely comfortable in the box will be loose by the end of the season.

For a child, check it again at the start of every season rather than assuming last year’s helmet still fits. Heads grow faster than you expect and the fit goes off before the helmet looks any different.

Tell us the series as well as the measurementHead circumference in centimetres and which championship or club you are running in. The homologation narrows the choice more than the size does, and we would rather get both right at once. Call 0115 989 3488 or email Sales@GSMPerformance.co.uk.

Ladders read from the size options on our own products, which carry the head measurement in the size name. Bell numeric models follow Bell’s published HP, Carbon and Pro chart. Arai and OMP kart ladders match their published car ladders. All checked 2 August 2026.

Have you written anything about this exact product?
Yes, we have covered this exact product: New Stilo ST5 CMR Carbon Kart Helmet Now Live. That is first-hand coverage from our own builds and showroom, not brochure copy.

How do I get the right size?
Measure around your head at the widest point, about an inch above your eyebrows, and match the centimetres to the size options (this one runs from roughly 54cm to 59cm). The fit should be snug all round with no pressure points, and it should not rotate when you shake your head. Between sizes, try the smaller one first, as linings bed in. Our helmet buying guide covers fit in detail, or call us and we will talk it through.

Is it legal for competition karting?
This helmet carries Snell-FIA CMR 2016, a karting standard. CMR and CMS are the youth standards, the only ones accepted for karters under 15, so this is the right type of lid for cadet and junior classes. Karting standards are separate from the car racing list, so if you also race cars you will need a helmet from our motorsport helmet range. Check your club or championship regulations for the accepted list.

How do I look after it?
Store it in its bag away from heat and direct sun, clean the shell with mild soap and water only (solvents attack the finish and the shell), and let the lining air out after use. And the big one: after any significant impact, replace the helmet even if it looks fine, as the protective liner is designed to crush once.

Availability

Stilo comes from central distribution

Stilo works the same way as Bell. Stocked items are around 10 working days, and special order items extend to around 20 days.

The helmets are often special order

Much of the Stilo helmet range is built rather than stocked, and those orders can run past 20 days.

Before you order

Contact us with the model and size and we will confirm the current lead time on that exact helmet.

Stilo ST6 KRT Carbon Kart Helmet

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Guides and advice

GuideNew Stilo ST5 CMR Carbon Kart Helmet Now Live
GuideHow to choose a motorsport helmet, from £310 to £2,000
GuideWhat Kit Do You Need For Your First Track Day?
GuideHillclimb and sprint racewear requirements for 2026

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