I have a Black Diamond HalfDome helmet I use for rock climbing. enter image description here

Is it safe for me to bike with it or should I wear a regular helmet?

  • 6
    This one won't be as good as a proper cycling helmet. However any helmet is better than no helmet.
    – Criggie
    Commented Nov 25, 2016 at 19:09
  • 1
    see also ski helmet and military helmet
    – Móż
    Commented Nov 25, 2016 at 21:17
  • It should be marked with a Standards Compliance stamp. Read the standard and compare. With so little ventilation it would be hot to ride in.
    – andy256
    Commented Nov 26, 2016 at 5:19
  • Aside from legal issues, your main problem would be the poor ventilation. And the helmet is probably not as good at protecting you from the main biking hazard -- having your head hit the pavement -- since it likely does not have the right sort of "crushable" liner. Commented Nov 26, 2016 at 12:41
  • Cross SE-relevant opposite at outdoors.stackexchange.com/questions/1576/…
    – Criggie
    Commented May 18, 2020 at 2:30

2 Answers 2


They are designed for different things: climbing helmets have more protection against sharp object penetrating the shell from directly above, while bicycle helmets have more protection for a high force hit with a blunt object (the ground, car bonnets etc) from the sides, front and back.

If helmets are required where you live, unless the climbing helmet meets the standards (EN 1078, CPSC etc) required by your country for cycling helmets, (some might, I don't know) you are not riding legally.

Even the safety benefit of wearing a helmet is hotly debated (refer What are the reasons for and against wearing a bicycle helmet?; wearing the wrong type of helmet is an unproductive debate that will have no useful outcome. Probably what will not be debated too hotly is "If you are in an accident, wearing a climbing helmet is safer than not wearing a helmet" and "It's best to wear a bicycle helmet that meets a recognized standard".

I suggest you refer to discussions in related questions such as are ski helmets safe and Would a military helmet make a safe alternative to a bicycle helmet?.

  • 11
    "benefit of wearing a helmet is hotly debated" - I hate this trend? Most of the contention I have seen is mixing up population level and individual level effects (ecological fallacy). Just because there is not a measurable benefit at the population level, does not mean there is a lack of benefit at the individual level. This has to do with taking averages across heterogeneous groupings. Like you suggest, if you are going to get into an accident, a helmet is better than no helmet.
    – Rider_X
    Commented Nov 25, 2016 at 20:59
  • I will add that some climbing helmets do have EPS foam with a shell (similar to a bicycle helmet). The EPS foam is what provides the benefit of extending the duration of impact, and thereby reducing peak forces experienced by the brain (total energy is the same, but how you distribute it over time is the key component). As you correctly point out, even if your climbing helmet has EPS foam, the helmet itself was not designed for cycling so it is unclear how they will perform in typical cycling accidents.
    – Rider_X
    Commented Nov 25, 2016 at 21:06
  • "Even the safety benefit of wearing a helmet is hotly debated" -- By whom? I have never heard anyone debating this, much less... hotly. Are these weasel words?
    – user13220
    Commented Nov 26, 2016 at 10:57
  • 1
    @BaileyS - I've certainly seen this debate. Just google "are bike helmets safer" to see some examples. Commented Nov 26, 2016 at 11:52
  • 1
    @eldering spinal injuries have to do with glancing blows or off angle contact. Hard shell helmets reduce this problem greatly. MIPS is predicted to reduce it further. Some of these "gottcha" are related to old studies on old tech.
    – Rider_X
    Commented Nov 26, 2016 at 14:40

No, climbing helmets are not safe bicycle helmets.

There are rigorous certification processes for bicycle helmets informed by decades of experience... take advantage of them!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.