Walk into any motorcycle dealership or gear website, and you will see elbow pads, shoulder cups, and back protectors branded with “CE Level 1” or “CE Level 2.” While most riders know that Level 2 offers better protection, very few understand the actual mechanical testing standards or the kilonewton (kN) numbers behind them.
Knowing the difference between transmitted impact force ratings helps you decide when lightweight Level 1 inserts suffice and when high-density Level 2 armor is mandatory.
The Testing Standard: EN1621-1 and EN1621-2
European Norm (EN) standards dictate impact limits for motorcycle limb protectors (EN1621-1) and back protectors (EN1621-2). Testing labs drop a 5-kilogram steel striker from a specific height onto the armor piece, delivering exactly 50 Joules of kinetic energy. Sensors underneath measure how much force passes completely through the armor into the human body.
| Certification Level | Max Transmitted Force (Limb / EN1621-1) | Max Transmitted Force (Back / EN1621-2) | Impact Reduction Ratio | Best Application |
|---|---|---|---|---|
| CE Level 1 | < 35 kN (Average) | < 18 kN (Average) | ~70% to 75% | Urban riding, low-profile casual shirts |
| CE Level 2 | < 20 kN (Average) | < 9 kN (Average) | ~85% to 90%+ | Highway commuting, touring, track riding |
The math is striking: CE Level 2 limb armor cuts the transmitted force nearly in half compared to Level 1, transferring no more than 20 kilonewtons of energy to your joints during an identical 50-Joule strike. For back protection, Level 2 drops allowable peak transmitted force from 18 kN down to 9 kN, directly reducing the risk of spinal fracture. code Code 50 JOULE STRIKER IMPACT | v +———————–+ | MOTORCYCLE ARMOR | +———————–+ | [ Transmitted Force ] | Level 1: Up to 35 kN passes through Level 2: Under 20 kN passes through (43% less blunt trauma) code Code
Traditional Hard Shells vs. Non-Newtonian Polymers
Motorcycle armor has shifted dramatically from rigid plastic cups backed by standard EVA foam to advanced smart polymers such as D3O and SAS-TEC. D3O & Non-Newtonian Behavior: Normal State —> Molecules float free (Soft, flexible, molds to body) Impact Shock —> Molecules lock rigid in milliseconds (Disperses energy across pad) Post Impact —> Returns to flexible resting state immediately code Code Traditional hard shells rely purely on material thickness and rigid outer plastics to deflect blows. Non-Newtonian materials, by contrast, behave like a liquid under slow movement—adapting to your elbow or knee bend—before instantly locking their molecular chains into a rigid matrix upon rapid impact shock. This provides Level 2 protection in a low-profile pad that remains comfortable all day.
Upgrading Your Factory Gear Armor
Many jackets in the $130 to $250 price bracket ship with basic CE Level 1 foam inserts in the shoulders and elbows, paired with a simple non-certified foam shipping pad in the back pocket.
Upgrading the back pad to a CE Level 2 non-Newtonian insert is the single highest-return safety investment you can make, typically costing between $35 and $60.
The Verdict
- Stick with CE Level 1 if: You commute at low city speeds (under 35 mph), prioritize maximum breathability and flexible movement, and wear tailored single-layer riding shirts.
- Upgrade to CE Level 2 if: You ride at highway speeds, participate in track days, go adventure touring, or want maximum joint and spine protection against heavy impact trauma.