The visor supplied with this helmet is not road legal. LS2 sells the IRID Dynamic Dark for daylight track use, and its darkened state falls below the light transmission a road-approved visor must reach — that is the first thing to know, and it is also the clue to who this article is for. Everything about this package is built around the day you sign on at a circuit: a gloss carbon FF805 Thunder GP Aero at 1,280 g declared, and a photochromic screen that follows the light instead of making you carry three.

What a track day actually asks of a helmet

Nobody writes this down, so here it is in the order the day happens.

Scrutineering looks at the shell and the strap. An ECE 22.06 label and an undamaged shell get you through at almost every open pit-lane day in Europe; a licensed race is where FIM homologation starts to be asked for, and that is the GP PRO rather than this helmet. Your fastening will be checked, and a double D-ring is what organisers want to see.

Sessions ask for airflow and a clear view. A helmet that ventilates well at 60 km/h can still cook you in a queue at the pit exit, which is why intakes you can open with gloves on matter more than the number of them.

Lunchtime asks about weight. The difference between 1,280 g and 1,500 g is invisible in the first session and decides whether your neck is still fresh in the last one.

And the worst case asks about the cheek pads. LS2's Emergency Release System — red tabs that pull the padding out of the shell — lets a marshal take the helmet off without rotating your neck. It is the single item on the specification sheet that exists purely for a day nobody plans for.

Why a photochromic earns its place on a circuit

Track light is not constant. A pit lane is shaded, a braking zone under trees is dark, the back straight at four in the afternoon puts the sun in your eyes, and a fixed dark visor is either right for one of those or wrong for all of them.

The Dynamic Dark swings between 60 and 20 per cent light transmission as ultraviolet reaches it. LS2 quotes 0.09 seconds for the transition and 20 g for the visor, with no batteries and an integrated anti-fog coating tested to 120 seconds. We pass the transition figure on as their claim: photochromic chemistry is usually slower than that, and cold weather slows it further while making the dark state darker.

What you get in practice is one screen for a whole day, and one fewer thing to fumble with in a hot pit box.

Getting there and back

You still need a legal visor for the road. The helmet arrives with a screen fitted and LS2 packs a tinted one as well, so the answer is to ride there on the standard screen, fit the Dynamic Dark when you arrive, and swap back before you leave.

The quick-release mechanism is tool-free, which is what makes that routine reasonable rather than a chore. Do the change on a flat surface: a dropped visor lands face down, and a scratch across your sightline is permanent.

What to pack besides the helmet

Since this article is built for circuit days, the short list that goes in the bag with it: the standard screen for the ride there and back, a couple of tear-off films already fitted rather than loose, a clean microfibre cloth, and the helmet bag it came in so the visor you are not wearing travels protected.

What not to pack is a bottle of household glass cleaner. It is the fastest way to take the anti-fog coating off a Pinlock lens and the anti-scratch layer off a visor, and neither comes back.

Gloss carbon

Clear coat over a visible 6K weave, so the twill catches light and the helmet reads dark charcoal rather than black. Gloss is also the finish that repairs: a scuff picked up in a paddock polishes out with a mild compound, where the same mark in matt clear coat is there for good.

The shell

100 per cent carbon fibre, 6K, moulded as one outer shell size for XS to XXL, at a declared 1,280 g with 50 g tolerance. Approved to ECE 22.06. The Thunder GP PRO above it is a different helmet — 9K cloth, three shell sizes, X-Static liner, FIM homologation — and that distinction is worth keeping straight if you are choosing between them.

One shell size is this helmet's honest compromise: the outside is the same at every size, and the fit is built from padding. Try one at the ends of the range.

Ventilation

Chin, brow and crown intakes, channels cut through the EPS, an exhaust below the rear spoiler, and a breath deflector to keep exhaled air off the screen. Gloved operation throughout, which is the specification that matters on an out lap.

Tear-offs and the Pinlock

The visor comes with tear-off posts already fitted and LS2 packs a set of films, so a wet or fly-heavy session does not need a separate order. A Pinlock 120XLT MaxVision lens is in the box for the standard screen — grade 120 is the strongest anti-fog film Pinlock makes, and MaxVision is the cut that reaches the edge of the aperture instead of sitting in your peripheral vision as a frame.

ECE 22.06, and what it does not cover

Eighteen impact points against five, several speeds, an oblique impact on an abrasive anvil measuring rotational acceleration, and a Brain Injury Criterion assessment instead of peak deceleration alone. Vents and visor mechanism are tested fitted. It applies to the helmet. It does not make the dark visor road legal.

What this helmet does not have

• No road-legal Dynamic visor. Daylight track use only for the dark one.
• No FIM homologation; a licensed race needs the GP PRO.
• No sun visor.
• One outer shell size across six helmet sizes.
• No SHARP, ADAC or Snell result for the FF805 Thunder.
• No noise measurement published, and none estimated here.

In the box

• LS2 FF805 Thunder GP Aero helmet — Gloss Carbon
• LS2 IRID Dynamic Dark photochromic visor — daylight track use only
• Carrying backpack
• Tinted visor
• Pinlock Max Vision 120XLT anti-fog lens
• Tear-off films
• Reflective stickers

LS2 publishes a single packing list for the GP Aero and none specific to the Dynamic versions; this is that list plus the visor the reference is built around.

Size guide

Size	Head circumference
XS	53–54 cm
S	55–56 cm
M	57–58 cm
L	59–60 cm
XL	61–62 cm
XXL	63–64 cm

Specification

• Helmet — LS2 FF805 Thunder GP Aero
• Reference — 168058816
• Surface — Gloss Carbon
• Second visor — LS2 IRID Dynamic Dark — daylight track use only, not road legal
• On the road — use the clear or tinted screen supplied with the helmet
• Certification — ECE 22.06 (helmet)
• Construction — Carbon 6K, single outer shell
• Declared weight — 1,280 g ± 50 g; visor 20 g
• Chin strap — double D-ring with emergency release pads
• Size range — XS–XXL (53–64 cm)
• Tint behaviour — photochromic, 0.09 s, mechanical, unaffected by cold batteries because there are none
• Fog control — coating tested at 120 s, plus the supplied Pinlock 120XLT MaxVision
• Airflow — three intakes, EPS channels, exhaust below the spoiler
• Lining — removable, washable, hypoallergenic laser-cut foam

• 1x LS2 FF805 Thunder GP Aero helmet — Gloss Carbon + IRID Dynamic Dark
• 1x LS2 IRID Dynamic Dark photochromic visor (daylight track use only)
• 1x carrying backpack
• 1x tinted visor
• 1x pinlock Max Vision 120XLT
• 1x tear-off films

Size guide — all measurements