Matt grey is the finish that asks the least of you over a few years of daily riding. It hides road film better than anything else here and sits meaningfully above black in the flat light a European commute actually supplies.

What this helmet is — and what changed for the R

MT's positioning for this helmet is honest: everyday riding at a price that leaves budget for the rest of your kit. It is not a touring helmet and not a track helmet, and it does not pretend to be either.

🔵 The predecessor's independent verdict — MCN 4/5 — described it as surprisingly good for the money, with ventilation as the main weakness. The 4 R's reworked intakes are MT's answer to exactly that.

About the matt grey finish

Value rather than colour decides both how dirty a helmet looks and how easily it is seen, and a mid grey sits at the useful point on that scale for both at once. Road film, dust and dried rain marks all show least here — they read as haze on black and as obvious marks on white. And a driver's eye resolves a mid-value object against dark tarmac appreciably faster than a dark one. Neither property is dramatic alone; together they make this the version that needs the least attention. 🔵 Like every matt finish it is washed rather than polished, and it is 13 € below the graphic versions.

The SHARP stars that belong to a different Thunder

🔵 A pass mark and a rating are different things. ECE 22.06 is a pass mark that every helmet sold in Europe must meet, and the Thunder 4 R SV meets it in full — more impact points and higher speeds than the superseded 22.05, plus a rotational assessment.

A SHARP star rating is comparative, and this helmet has none. The four-star „MT Thunder" and „Thunder 3" are earlier models.

HIRP, two shells and ECE 22.06

Full ECE 22.06 approval means the current schedule rather than the superseded 22.05: more impact points, higher test speeds, and a rotational-impact assessment the older standard did not include.

🔵 On a helmet at this price that is the specification most worth checking, and a good number of rivals still hold only 22.05.

MT-QVSS, the visor lock and the Pinlock in the box

Fogging is decided at low speed — junctions, traffic, waiting — where there is no airflow to clear a visor. The supplied Pinlock DKS435 lens is the answer, and it is fitted from new rather than left in the box.

🔵 It is a consumable: the silicone seal loses grip and the surface clouds after a few seasons. Order replacements as DKS435.

The integrated sun visor

🔵 With the shield down and the outer visor closed you are looking through two surfaces, and any scratch or fog on either becomes visible. Keep both clean, and never wipe either dry.

The shield retracts fully into the shell rather than sitting part-way in your upper field of view.

Enlarged intakes and a revised spoiler

🔵 In stationary traffic no helmet ventilates well — airflow needs airflow. Where a commuting helmet is most tested is exactly there, and a pale shell does more for you at a standstill than any vent setting.

The 4 R's intakes are enlarged over the previous generation's, which were the model's noted weakness.

Interior, fit and retention

🔵 Fit is the specification that matters most and the one no description settles for you. A loose helmet moves under braking and rotates in a crash; a tight one produces a headache at forty minutes.

Try it on and keep it on for ten minutes. Measure around the widest part of your head, about 1–2 cm above the eyebrows.

Intercom preparation and speaker pockets

🔵 Check speaker depth before buying any intercom, not just diameter. A speaker that is too deep presses even in a recess, and on a helmet at this price the padding has less spare depth to give than on a premium one.

The pockets here are sized for MT's own MT-B01 Rider Sync system.

Where it sits in MT's range

🔵 The most useful comparison is not against premium helmets but against other 157-euro full-face helmets. At this price most supply no anti-fog lens, no sun visor and a visor that needs tools.

What the Thunder 4 R SV gives up in return is shell material — HIRP rather than composite — and roughly 150–300 g.

When something wears out

🔵 Replacement cheek pads are the most useful spare part on any helmet and the least often bought. They correct a fit that has loosened with wear and solve a hot spot that would otherwise mean a different helmet entirely.

Genuine MT pads for the Thunder 4 R SV are available, as are complete linings.

In the box

• MT Thunder 4 R SV helmet — Pure A2 (HIRP shell)
• Clear MT-V-28C visor, fitted
• Pinlock® DKS435 MaxVision anti-fog insert
• Nose deflector
• 🔵 No intercom — the helmet is prepared for the MT-B01 Rider Sync system; the system is a separate purchase

Size guide

Specification

• Model — MT-Helmets Thunder 4 R SV
• Part number — 137500PA2203
• Colour — Pure A2 — Matt grey
• Homologation — ECE 22.06 — the current European standard
• 🔴 Safety rating — none. SHARP's four-star „MT Thunder" and „MT Thunder 3" are different, earlier models; the Thunder 4, 4 SV and 4 R have not been tested. No ADAC or Snell result either
• Independent verdict — MOTORCYCLE NEWS 4/5 — 🔴 for the predecessor Thunder 4 SV („surprisingly good for less than £120"), which named ventilation as its main weakness. No test of the 4 R exists yet
• Helmet type — Full-face, everyday / commuting
• Shell — HIRP (High Impact Resistant Polymer); two outer shell sizes
• Weight — approx. 1500 g ±50 — 🔴 MT publishes no separate figure for the 4 R; this is the documented Thunder 4 SV / HIRP-platform weight
• Sizes — XS to 3XL (seven sizes)
• Visor — MT-V-28C on the MT-M-28X mechanism, with MT-QVSS tool-free quick swap and a lock against unintended opening
• Anti-fog — Pinlock® DKS435 MaxVision included as standard
• Sun visor — integrated drop-down, single slider, retracts fully into the shell
• Ventilation — enlarged intakes and a revised spoiler for this generation — MT's answer to the criticism levelled at the Thunder 4 SV
• Retention — micrometric ratchet buckle
• Interior — fully removable and washable, with dedicated speaker pockets
• Communication — prepared for MT-B01 (MT Rider Sync) — system sold separately
• Also supplied — nose deflector
• Impact liner — expanded polystyrene — crushes once and does not recover; replace the helmet after any real impact
• Serviceability — visor, Pinlock lens, lining, cheek pads, sun visor and nose deflector all available separately
• Replacement guidance — after around five years of use regardless of condition, and immediately after any impact
• Manufacturer — MT-Helmets (MT Helmets, Spain)
• Sizing note — measure around the widest part of your head, about 1–2 cm above the eyebrows. With two outer shell sizes, try the size the chart gives you rather than ordering by tape alone — the fit at the shell boundary is less precise than on a three-shell helmet
• Made for — commuting, everyday riding and country roads at ordinary speeds — not a long-distance touring or track helmet
• Care — wash the lining by hand a few times a season; never wipe the visor or the sun visor dry, as road dust scratches both permanently

• 1x MT Thunder 4 R SV helmet
• 1x MT-V-28C clear visor (Pinlock Max Vision ready)
• 1x Pinlock DKS435 anti-fog insert
• 1x nose deflector
• Integrated drop-down sun visor (built in)