Gear Size Guide
Helmets, gloves, and jackets. How to measure correctly and what to look for as a rider in Singapore.
How to measure your head
One number, your head circumference in centimetres, is where every helmet size starts. Use a soft fabric tape measure. A rigid steel tape will read too high because it can't follow the curve of your skull.
How to measure
- Use a soft fabric tape measure, not a rigid ruler.
- Position the front edge 2.5cm above your eyebrows.
- Pass the tape above your ears on both sides.
- Wrap it around the widest part of the back of your head, the bump you can feel.
- Keep the tape level. Take 2 to 3 readings. Use the largest number.
- Record in centimetres. Every helmet chart is metric-first.
Measuring over a ponytail or bun inflates the number. Pulling the tape too tight gives a too-small reading. Skipping the back-of-skull bump is the most common error. Don't trust your hat size or the number inside your last helmet. A Shoei M and an AGV M are not the same helmet.
Head shape matters as much as size
Head circumference tells you what size shell fits around your head. Head shape is a big part of whether that shell actually feels right inside. As a rule of thumb the industry sorts heads into three broad categories, but real heads sit on a continuum and most people aren't a perfect match for any single one. Treat this as a starting point, not a verdict. Tap the one that sounds closest to you.
Tightness at the temples (the sides) with a gap at the forehead and back often points to a rounder head. Many riders here find a rounder or "Asian fit" interior more comfortable, but fit varies by model and by person, so treat this as a hint and try the helmet on.
How to find your shape: Take a top-down photo. Flatten your hair, have someone shoot straight down at your crown, and compare the outline to the shapes above. A quicker check is to wear a standard intermediate-oval helmet for 20 to 30 minutes. A red mark across the forehead often points to a longer oval, pressure on the temples to a rounder head, and even pressure all around to an intermediate shape. These are guides, not diagnoses.
Peer-reviewed head-shape research (Ball et al., Applied Ergonomics, 2010) found East Asian heads average rounder, with a flatter back and forehead, than Western heads. That's a population average with plenty of individual overlap, not a rule about any one rider. A helmet whose interior is a poor match for your head can leave pressure points, usually at the temples or forehead, that don't ease as you ride and can lead to discomfort or a pressure headache over a longer trip. The rigid safety foam won't reshape to fix a wrong-shaped shell. That's why many riders here look for a rounder or "Asian fit" interior, and why several Japanese and Asian-market helmets suit rounder heads well. But interior shape varies by model, not just by brand, and many brands sell region-specific versions, so always check the specific model and try it on before you commit.
Helmet size chart
All measurements in centimetres. Charts are a starting point. Always try a helmet on before buying to check it actually fits your head shape, not just your head size.
| Size | Head (cm) | Shoei | Arai | HJC | LS2 |
|---|---|---|---|---|---|
| XS | 53 to 54 | ✓ | ✓ | 54 to 55* | ✓ |
| S | 55 to 56 | ✓ | ✓ | ✓ | ✓ |
| M | 57 to 58 | ✓ | ✓ | ✓ | ✓ |
| L | 59 to 60 | ✓ | ✓ | 58 to 59* | ✓ |
| XL | 61 to 62 | ✓ | ✓ | 60 to 61* | ✓ |
| XXL | 63 to 64 | ✓ | ✓ | 62 to 63 | ✓ |
| 3XL | 65 to 66 | ✓ | ✓ | 64 to 65 | ✓ |
* HJC uses a 1cm shift at certain boundaries. Check HJC's specific chart for the model you're buying.
There's no universal answer, and it's easy to get wrong, so check the sizing instructions for the specific model you're buying. As a general pattern, snug-fitting brands like Shoei and Arai are often sized down because their comfort padding settles a little over the first few weeks, while some other brands advise sizing up. When in doubt, ask us or try both sizes on.
Break-in. What changes, what doesn't.
Your helmet has two foam layers. Only one of them changes over time.
If your helmet starts feeling noticeably looser after extended use, you can step up one cheek-pad thickness. Several brands (Shoei, Arai, HJC and others) sell replacement cheek pads in a range of thicknesses, so you can fine-tune fit rather than replace the helmet. Ask us what's available for your model.
When to replace your helmet
This is general guidance drawn from manufacturer and safety-body advice, not a warranty or a fixed expiry date. An unused helmet stored well may last longer, and a heavily used one less. When in doubt, have it checked or replace it. Sources are listed at the foot of this page.
What a correctly-fitted helmet feels like
Headaches or numbness soon after putting it on (often in the first 15 to 20 minutes) that don't ease with time usually point to a head-shape mismatch, not break-in. Red marks at the forehead or temples lasting more than 30 minutes after removal are the same signal. A helmet that rocks forward and back even with the strap tightened is usually too big from day one. Signs like these generally mean you need a different shape or size rather than more riding time, so it's worth trying an alternative.
Glove sizing
Measure your dominant hand's circumference behind the knuckles, across the widest part of the palm, excluding the thumb. Make a relaxed fist. Check both hands and size to the larger number.
| Size | Hand circumference (cm) | Alpinestars | Dainese | RS Taichi (Japan) |
|---|---|---|---|---|
| S | 19 to 20 cm | 17.8 to 20.3 cm | 20.3 cm | 22.0 cm |
| M | 21 to 22 cm | 20.3 to 21.6 cm | 21.6 cm | 23.0 cm |
| L | 23 to 24 cm | 21.6 to 22.9 cm | 22.9 cm | 24.0 cm |
| XL | 25 to 26 cm | 22.9 to 24.1 cm | 24.1 cm | 25.0 cm |
| XXL | 27 to 28 cm | 24.1 to 25.4 cm | 25.4 cm | 26.0 cm |
RS Taichi and Komine run roughly one size smaller than European brands. A 21cm hand is a Medium in Alpinestars but a Small in RS Taichi. If you're cross-shopping a Japanese mesh glove, size up one letter and verify against the cm chart.
Leather gloves are made to break in. The leather naturally relaxes and moulds to your hand over the first few weeks, so some loosening from new is normal and expected, not a fault. Because of that, new leather should feel snug (never painful, with no bunched material or hot spots). How much a glove relaxes depends on the leather, the model, and how often you wear it, so treat the fit guide as a starting point. Textile and mesh gloves are made from materials that don't stretch, so buy those at the size that feels right on day one. If you're not sure what size to get, message us before you buy and we'll help.
For Singapore's climate: perforated leather with hard knuckle protection gives the best balance of abrasion resistance and airflow. Skip waterproof-membrane gloves for daily wear. They trap heat. Keep a dedicated rain pair instead.
Jacket sizing
Wear only a thin t-shirt when measuring. Wrap the tape around the fullest part of your chest, under your armpits, across your shoulder blades, parallel to the floor. Measure how your body actually sits when you're riding, not with a deep breath in.
| Size | Chest (cm) | Chest (in) |
|---|---|---|
| XS | 86 to 91 | 34 to 36" |
| S | 91 to 97 | 36 to 38" |
| M | 97 to 102 | 38 to 40" |
| L | 102 to 107 | 40 to 42" |
| XL | 107 to 112 | 42 to 44" |
| XXL | 112 to 117 | 44 to 46" |
| 3XL | 117 to 122 | 46 to 48" |
- Dainese and Italian race-cut brands run slimmer through the chest and waist with longer sleeves. Broad-shouldered riders often need to go one size up.
- Japanese brands (RS Taichi, Komine, Scoyco) run smaller. A Japanese "Large" sits at roughly 95 to 100cm chest, which is a Western Medium. Size up one letter and verify.
- Komine "B" and "T" modifiers are wide and tall variants. Useful for riders whose waist or height doesn't track their chest measurement.
The temptation in 33 degrees humidity is to buy a jacket one size larger so air can circulate. A loose jacket means armour shifts away from the impact point in a crash, fabric flaps at highway speed, and mesh panels stop working because air flows around your body instead of through it. Choose a jacket with more or larger vents instead.
Check armour placement in riding posture. Zip the jacket fully and lean forward, hands forward, arms slightly bent. Shoulder armour should stay centred when you raise your arms. Elbow armour should sit on the point of the elbow at 90 degrees. If armour shifts more than about an inch, the jacket fits wrong regardless of how many vents it has.
CE armour tip: most jackets ship with Level 1 shoulder and elbow pads and a soft foam back pad. The single most cost-effective safety upgrade is replacing that back pad with a CE Level 2 back protector. SAS-TEC, D3O, or Forcefield options typically cost under SGD 80.
Good to know & sources
This guide is general educational information, not a fitting or medical assessment. Every head and every helmet is different, so use it as a starting point and, ideally, try a helmet on before you buy. Always follow the fitting, care and replacement instructions that come with your specific helmet. Where they differ from anything here, follow the manufacturer.
Helmets are safety equipment with a limited service life. Replace yours after any crash or significant impact, and in line with the manufacturer's stated replacement interval, even if it still looks fine.
Selected sources for the fit and helmet-life guidance above:
- SHOEI, helmet care & replacement (about 5 years from first use / 7 from manufacture): shoei-europe.com/faq
- Arai, helmet lifespan & replacement guidance: whyarai.co.uk/support/faqs
- Snell Memorial Foundation, helmet FAQ (replace after impact; 5-year guidance): smf.org/faq
- RevZilla / Common Tread, how to buy and size a motorcycle helmet (break-in of comfort padding): revzilla.com
- Arai, the three head shapes (long / intermediate / round oval): araiamericas.com
- Ball et al., “A comparison between Chinese and Caucasian head shapes,” Applied Ergonomics 41(6), 2010: sciencedirect.com
