4 ms·

I've raced for about 6 years now and have not replaced my tri helmet, but have replaced the one I use when I'm on my road bike (only because it broke in a crash

I've raced for about 6 years now and have not replaced my tri helmet, but have replaced the one I use when I'm on my road bike (only because it broke in a crash), where did you hear that you should replace the helmet that frequently?

Alex3917 7y ago
Any safety equipment made from plastic needs to be replaced every 3 - 5 years because it's weakened by light and air. Same for rock climbing ropes, life jackets, children's car seats, etc.
- semi-extrinsic 7y ago
  The official guidance for life jackets is 10 years. https://www.secumar.com/en/servicing/ https://www.secumar.com/en/servicing/ For bike helmets, independent safety labs have actually done the science and found no measurable deterioration in impact testing nor material properties with helmets as much as 26 years old. (Link to journal paper at end of summary linked below.) https://helmets.org/up1505a.htm https://helmets.org/up1505a.htm
- usrusr 7y ago
  Rock climbing ropes have very clear performance metrics. "Hard hat" style helmets are similar, they are made to protect from falling projectiles like tools or rocks and must not break. Bicycle helmets just add a few mm of valuable deceleration distance in the best case, that's all they do apart from protecting from purely cosmetical abrasions. The maximum amount of extra deceleration distance is provided at one very specific kind of impact. When the material properties change, the maximum will be achieved at a different impact. But you cannot predict which one you will have that one time when you actually use the helmet. The old one might be better or worse, nobody knows. If manufacturers knew exactly what would eventually hit you, lots of engineering could be applied to precisely tune the helmet to that impact, but they don't know so they cannot do that. So all the engineering goes into achieving comfort while hitting regulation targets and into marketing features that only need to appeal to "common sense". There is no engineering at all going into the main purpose. Even aerodynamics, a clearly defined performance metric orthogonal to protection, is just barely starting to move on from hand-wavey "fast looks" to actual engineering.

Alex3917 7y ago

Any safety equipment made from plastic needs to be replaced every 3 - 5 years because it's weakened by light and air. Same for rock climbing ropes, life jackets, children's car seats, etc.

semi-extrinsic 7y ago
The official guidance for life jackets is 10 years. https://www.secumar.com/en/servicing/ https://www.secumar.com/en/servicing/ For bike helmets, independent safety labs have actually done the science and found no measurable deterioration in impact testing nor material properties with helmets as much as 26 years old. (Link to journal paper at end of summary linked below.) https://helmets.org/up1505a.htm https://helmets.org/up1505a.htm
usrusr 7y ago
Rock climbing ropes have very clear performance metrics. "Hard hat" style helmets are similar, they are made to protect from falling projectiles like tools or rocks and must not break. Bicycle helmets just add a few mm of valuable deceleration distance in the best case, that's all they do apart from protecting from purely cosmetical abrasions. The maximum amount of extra deceleration distance is provided at one very specific kind of impact. When the material properties change, the maximum will be achieved at a different impact. But you cannot predict which one you will have that one time when you actually use the helmet. The old one might be better or worse, nobody knows. If manufacturers knew exactly what would eventually hit you, lots of engineering could be applied to precisely tune the helmet to that impact, but they don't know so they cannot do that. So all the engineering goes into achieving comfort while hitting regulation targets and into marketing features that only need to appeal to "common sense". There is no engineering at all going into the main purpose. Even aerodynamics, a clearly defined performance metric orthogonal to protection, is just barely starting to move on from hand-wavey "fast looks" to actual engineering.