“AAA = 120 km/h” is repeated everywhere — and we could not verify that it appears in the standard itself. It is a simplification put forward by manufacturers. What follows is what EN 17092 actually measures, and why two pairs of jeans both labelled AA can be far apart.
Why shorts are the most common mistake
Table of contents17
In a slide, the first three areas to hit the ground are usually knees, hips and elbows. Two of those three are on the lower body — exactly the part that shorts leave uncovered.
This is not only a high-speed issue. At city speeds, dropping the bike on a U-turn is enough to take a wide graze off a knee and an ankle. That kind of injury is not life-threatening, but it ruins the rest of the trip, and it heals slowly in hot, humid weather.
Put plainly: any long trousers beat shorts, even uncertified ones. But if you are going to buy proper gear, it is worth knowing what the label says.
EN 17092 classes AAA, AA, A, B and C
Riding trousers are graded under the same standard as jackets: EN 17092:2020, with five classes in descending order — AAA, AA, A, B, C.
| Class | Required armour | Abrasion performance |
|---|---|---|
| AAA | Knee and hip (plus shoulder and elbow on jackets) | Highest |
| AA | Knee and hip | Below AAA |
| A | Knee required, hip optional | Below AA |
| B | No armour | Equivalent to Class A |
| C | Armour only | No guaranteed minimum |
A Class A pair may have no hip armour at all — and the hip is one of the first points to reach the ground. That is the most worthwhile distinction between A and AA.
What the test actually measures
The impact abrasion test uses a rotary machine (the Darmstadt method): three arms carrying fabric samples are spun up to the test speed above a concrete surface roughly 900 mm across, then released to slide freely until they stop.
It passes when none of the three samples forms a hole larger than 5 mm. That is the whole criterion — not a score, not a number of seconds.
The test speeds cited in technical write-ups are 120, 75, 70, 45 and 25 km/h. Pending verification: we could not confirm that the standard itself assigns one of those speeds to each class. The neat “AAA = 120, AA = 70, A = 45” framing appears in manufacturer material, not as a quotation from the standard.
Why two “AA” garments can differ
This argument comes from a protective-fabric maker, and it is worth taking seriously: a class is a floor, not a value. A pair that scrapes past the AA threshold and a pair that clears it by a wide margin both carry the same AA label.
The practical consequence: the class tells you the floor, not how far above it the garment sits. So when two pairs share a class, keep comparing — armour quality, pocket position and fit — rather than treating them as equivalent.
Riding jeans vs textile vs leather
- Riding jeans. Look like ordinary denim and stay wearable off the bike — the biggest advantage for a traveller. The trade-off: soaked denim takes a very long time to dry, and the denim itself is usually the outer shell, with the sliding performance coming from a reinforced lining inside.
- Technical textile. Light, dries fast, real vents, adjustable armour pockets. The most practical for long days in heat.
- Leather. Slides well but is heavy and barely breathes; at 35°C almost nobody wears it all day.
One technical point about jeans: the standard assesses the layer closest to the body. So a pair with reinforcement only at thigh and seat still has plain denim at the ankle. Check how far the lining reaches, not just the class on the label.
Knee and hip armour inside
Armour fitted in trousers is tested to EN 1621-1, with zone codes K (knee), H (hip), L (lower leg) or K+L. How to read the levels is covered in the article on CE Level 1 vs Level 2 armour.
Two common mistakes:
- Assuming an empty pocket means armour. Plenty of trousers ship with armour pockets but no protectors — or with an unmarked foam placeholder.
- Buying the right level but the wrong zone code. A pad tested for the knee is not automatically qualified as a hip protector.
Keeping armour in place on a scooter seat
This is the part almost nobody writes about, even though it decides whether the armour does anything at all.
Riding trousers are cut for a motorcycle riding position: knees bent, torso tipped slightly forward. On a scooter your legs are stretched out in front and the knee bends far less — so the knee pad tends to slide down below the kneecap.
The check takes seconds: sit in your actual riding position and feel where the pad is. If it has dropped below the knee:
- Choose trousers with height-adjustable armour pockets — usually a hook-and-loop strip inside.
- Or use separate strap-on knee guards, which grip the leg rather than the trousers.
Choices for heat and rain
In northern Vietnam these two requirements pull against each other, and the practical answer is the same as with jackets:
- Breathable trousers plus rain overtrousers are usually more comfortable than a membrane sealed in all through a hot day.
- Overtrousers come off when the rain stops; an internal membrane does not.
- Jeans are the worst choice for several wet days, simply because they will not dry overnight.
Quick checklist
- Are the letters AAA, AA, A, B or C next to the CE mark?
- Is there real armour in the pockets, or just unmarked foam?
- Does the zone code match where you intend to fit it (K for knee, H for hip)?
- Is there hip armour — or is this a Class A pair with the hips left out?
- Sitting in your riding position: is the knee pad still over the knee?
- For jeans: how far does the reinforced lining actually reach?
Riding trousers are not included with the rental, so this is something you bring yourself. If you are only riding a few days in the city and do not want to buy dedicated trousers, thick long trousers plus strap-on knee guards is a sensible first step — covered in the article on separate knee and elbow guards. Before you travel, ask Mr Tú – Old Quarter Motorbike Rental what comes with the rental so you only pack what is missing.
Frequently asked questions
Do ordinary jeans protect you?
Better than shorts, but they are not tested to any standard. Ordinary denim tears fairly early in a slide; riding jeans differ by having a reinforced lining inside.
Is AAA really 120 km/h?
We could not verify that the standard says so. It is a manufacturer’s simplification. The published pass criterion is no hole of 5 mm or larger in the layer closest to the body.
Are two AA-rated pairs equivalent?
Not necessarily. The class is a floor the garment must clear, not a score it achieved. Keep comparing the armour, pockets and fit.
Does Class A include hip armour?
Not reliably — at Class A, hip armour is optional. If you want to be certain of hip protection, look at AA or above, or check each pocket.
Do I need riding trousers on a scooter?
Not legally. But the scooter seating position makes knee armour more likely to sit out of place, so if you wear it, check the position while seated.
Does the rental include riding trousers?
No. Riding trousers are not among the items that come with a rental bike, so bring your own if you want them.
Are riding trousers too hot?
Technical textile with vents is manageable; leather is very hard going at 35°C. Jeans sit in between but are slow to dry once wet.
Comments