What each one is certified to
This is where the comparison should start, because the standards are different and the difference is informative.
- Back protectors are certified to EN 1621-2. A protector is struck in a controlled impact test and graded on how much force is transmitted through it. Level 1 passes below a set threshold; Level 2 transmits roughly half that. It is a static, repeatable measurement of one thing: blunt impact on the spine area. Our CE ratings guide covers the whole EN 1621 family.
- Airbag vests are certified to EN 1621-4.That is the part of the family written for inflatable protectors, and it tests the system inflated — which means the certification covers the deployment as well as the cushion. The AIROBAG Wise Vest publishes EN 1621-4 Level 2 at the back and Level 1 at the chest; the Hit-Air MLV2 publishes EN 1621-4:2013 Level 1 at the back; Alpinestars publishes Level 2 impact performance under the EN 1621-4 test method for the Tech-Air 5.
Note what falls out of that. An airbag is not automatically “more certified” than a back protector. A $55 Leatt insert publishes EN 1621-2 Level 2; a $659 Hit-Air MLV2 publishes EN 1621-4 Level 1 at the back. Those are different tests and the numbers are not directly comparable, but anyone assuming the expensive product carries the higher published level is assuming wrong.
What the airbag does that armor cannot
Everything above is an argument about published test numbers, and it would be dishonest to leave it there, because it does not capture what an airbag is for. A back protector protects the area it covers, at the moment of the hit. An airbag inflates before impact and covers a much larger area including the collarbone, the ribs, the chest and, on full-torso systems, the neck— and it adds volume, which is a different mechanism from spreading force through a plate.
That is a genuine capability gap and it is why airbags exist. The trade-offs are equally genuine:
| Back protector | Airbag vest |
|---|
| Standard | EN 1621-2, Level 1 or 2 | EN 1621-4, Level 1 or 2 |
|---|
| Area covered | Spine region only | Back, chest, ribs, collarbone; neck on some systems |
|---|
| Can it fail to work? | No moving parts, nothing to charge or arm | Yes — a flat battery, an unclipped tether or a non-deployment |
|---|
| Re-use after a crash | Replace the protector | Recharge or replace a CO2 cartridge; service the system |
|---|
| Running cost | None | Cartridges, charging, and on some systems a subscription |
|---|
| Rough cost | The price of a tank of fuel | The price of a helmet, or several |
|---|
Electronic or tethered — the airbag decision
If you are buying an airbag, the first fork is not brand, it is mechanism.
Electronic systems like the Alpinestars Tech-Air 5 use sensors and an algorithm to decide you are crashing and fire without anything physically connecting you to the bike. They protect you if you are thrown clear, they work on any bike you get on, and they need to be charged and worn correctly to work at all. The Tech-Air 5 is worn undera jacket and needs a shell with room for it — a snug-fitting jacket you already own may not be that shell.
Tethered systemslike the Hit-Air MLV2 and the AIROBAG Wise Vest work mechanically: a lanyard clips to the bike, and if you and the bike separate, the lanyard pulls a pin and a CO2 cartridge inflates the vest. There is nothing to charge, nothing to subscribe to and no algorithm to trust — and the honest catch is that you have to remember to clip in every single time, and unclip before you walk away. Tethered vests are worn over your jacket, which makes them the practical choice if you do not want to re-buy your jacket.
The cheapest fully-certified route in is the AIROBAG Wise Vest, which publishes EN 1621-4 Level 2 at the back, Level 1 at the chest, a 90 ms inflation time and a shell certified to EN 17092, in sizes S to 4XL. It is ranked on our airbag vest page, which goes through all five systems in the registry properly.
The order we would actually buy in
- Replace the foam in your jacket’s back pocket with a certified EN 1621-2 Level 2 protector. Tens of dollars, no behaviour change, and it fixes the most common gap in a riding wardrobe. Check the pocket size first — our armor inserts page covers what fits what.
- Fill the other empty pockets. Most jackets ship without certified elbow or shoulder armor either. Our back protector ranking and jackets with armor page cover the rest of the audit.
- Then consider the airbag, once the cheap protection is all in place. Buying an $870 airbag to wear over a jacket with a foam pad in the back pocket is spending in the wrong order.
One thing neither product does, and it is worth saying plainly: neither a back protector nor an airbag protects your head. If the money is finite, a certified helmet that fits properly comes before both, every time. Our beginner gear guide works through the whole head-to-toe order by budget.
