On 25/02/2019 19:15, Ian Smith wrote:
On Mon, 25 Feb 2019 09:37:35 +0000, RJH wrote:
On 24/02/2019 20:12, Ian Smith wrote:
On Sun, 24 Feb 2019 12:59:26 +0000, RJH wrote:

Common sense tells me that a cycle helmet can help in certain
circumstances - and it's worth wearing one on that basis.

What if wearing a helmet makes things worse in certain circumstances?

How do you determine that the circumstances that it makes worse are
less prevalent or less serious than the ones where it helps?

I can't think of a single likely circumstance where wearing a helmet
would make a cycling injury worse.

When I was last knocked off my bike I was not wearing a helmet and my
head didn't hit anything, but it did pass very close by a kerbstone.
Had I been wearing a helmet, there's a chance that rather than just
miss it would have hit the kerbstone, possibly tangentially and
wrenched my head round.


Just to follow up (I hadn't read this properly) I can see why you don't
wear a helmet - you could easily have died if you had.

Since I suffered absolutely no head or neck injury, a helmet simply
could not have helped - you can't get less than no injury. There are
easily foreseeable scenarios where it could have made matters worse.


Absolutely - simply scenarios that can and do happen every day that I
hadn't considered.

Also consider the consequences of risk compensation.


Yes. I have some issues with the deterministic aspects of psychology -
but if you as others say that wearing a helmet make drivers more likely
to hit you, and that opinion is informed by some expertise in the notion
of risk compensation, than I take that seriously. And I will reconsider
wearing a helmet.

Suppose I had some sort of lucky talisman that would protect you from
all injury if you ever fell off your bike with no other vehicle
around, but it made it twice as likely that you'd be hit by each car
that overtook you. Would you want one of your own? Your logic (i.e.
that it helps in certain circumstances, so must be good) suggests
you'd want the talisman, even though it nearly doubles the chances of
your death each time you go out riding (cyclists rarely die without
interaction with a motor vehicle).

Not sure I see your point there. Are you saying wearing a helmet makes
me twice as likely to be hit by a car?

No. "Suppose I had..." indicates a hypothetical. It's a thought
experiment. You're supposed to think about the hypothetical scenario
set out, consider what would happen if it were true, and then consider
whether that conclusion should influence what is true.


Your hypothesis rested on 'twice as likely'. I was wondering what led
you to form that hypothesis. You're supposed to test hypotheses, by the
way. Thought experiments - do what you want, obviously!


Cycle helmets are designed to help in the sort of impacts that arise
from falling off. They aren't designed to achieve very much in a
motor vehicle impact. That's why they have disclaimers on them saying
they aren't suitable for motor sport.

'Falling off' and 'vehicle impact' often happen at once, I'd have thought?

I have fallen off without any motor vehicle impact. I have been hit
by a motor vehicle and not fallen off. If you're hit by
fast-travelling motor vehicle that's likely to do more damage than the
ground does when you get to it.


OK, didn't know that either - quite a learning curve!

I'm not a complete zealot, btw - I don't believe they should be
mandatory. My choice is personal.

It's just that, before this thread, I thought the benefits outweighed
the risks. The kerb proximity thesis, risk compensation and drivers
actively hitting cyclists because they wear helmets, and the child death
statistics have made me think that I could be wrong. Cycle helmets could
be death traps. And you have been incredibly fortunate to have the
insights you have.

--
Cheers, Rob