Helmet sizing?

General cycling advice ( NOT technical ! )
User avatar
tykeboy2003
Posts: 1050
Joined: 19 Jul 2010, 2:51pm
Location: Swadlincote, South Derbyshire

Helmet sizing?

Postby tykeboy2003 » 27 Jan 2020, 10:20am

I've never worn a helmet but following my accident on 13th Jan (cracked skull, broken shoulder blade and several cracked ribs) my other half says she will leave me if I don't wear one in future...

I've seen one on ebay with 3 sizes, small (53 to 55cm), medium (55 to 57cm) and large (57 to 59cm). Exactly where should the measurement be taken.

thatsnotmyname
Posts: 189
Joined: 23 Jan 2020, 10:23am

Re: Helmet sizing?

Postby thatsnotmyname » 27 Jan 2020, 10:25am

Around the circumference of your head - across the forehead and above the ears.

User avatar
Mick F
Spambuster
Posts: 47831
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Helmet sizing?

Postby Mick F » 27 Jan 2020, 10:33am

Beat me to it!
Yes, it's circumference for (modern metric) hat sizing.

I prefer the Imperial way of diameter. I've a small head ind it's size 63/4", where most men have 67/8".
Mick F. Cornwall

Darkman
Posts: 144
Joined: 30 Aug 2019, 8:46pm

Re: Helmet sizing?

Postby Darkman » 27 Jan 2020, 10:33am

My advice would be to go to a bike shop and try some on. I found that whatever the size was listed as, some fit better than others and you also have to factor in comfort. I really fancied a Giro one but having tried it on in Halfords, the size I needed (and the biggest they had) was a bit tight, and I found it very uncomfortable around the pads. Others had the pads held on with plastic clips that dig into your head (seriously? Why would they design it like that?? :? ) Ended up with a cheapy Ridge one, which was the "same size" but a far better fit and more comfortable than any others they had.

I have a Specialized one now, because... you know... fanboy. :mrgreen:

User avatar
Audax67
Posts: 4652
Joined: 25 Aug 2011, 9:02am
Location: Alsace, France
Contact:

Re: Helmet sizing?

Postby Audax67 » 27 Jan 2020, 10:43am

Darkman wrote:My advice would be to go to a bike shop and try some on.


+1 on that. I was given a very expensive helmet a couple of years back, and although the size matches my hat size it's made for brachycephalics (squareheads, so to speak) as opposed to dolicocephalics (longer front to back than side to side). I'm the latter so I can't wear the thing.

That said, a few months back I took a flyer on a 30€ Chinese job from Amazon. It comes with a magnetic visor, it's a perfect fit and I can use visor and rain cover at once, which I couldn't with the pricey one.
Have we got time for another cuppa?

User avatar
Audax67
Posts: 4652
Joined: 25 Aug 2011, 9:02am
Location: Alsace, France
Contact:

Re: Helmet sizing?

Postby Audax67 » 27 Jan 2020, 10:53am

Mick F wrote:Beat me to it!
Yes, it's circumference for (modern metric) hat sizing.

I prefer the Imperial way of diameter. I've a small head ind it's size 63/4", where most men have 67/8".


Yebbut the UK measurement assumes that your head is perfectly circular. This is daft because UKsians are predominantly long-headed front to back.

https://en.wikipedia.org/wiki/Cephalic_ ... ex_map.jpg
Have we got time for another cuppa?

User avatar
mjr
Posts: 14741
Joined: 20 Jun 2011, 7:06pm
Location: Norfolk or Somerset, mostly
Contact:

Re: Helmet sizing?

Postby mjr » 27 Jan 2020, 11:01am

tykeboy2003 wrote:I've never worn a helmet but following my accident on 13th Jan (cracked skull, broken shoulder blade and several cracked ribs) my other half says she will leave me if I don't wear one in future...

I think you've got more serious problems than the fit of a hat, then. Does she know they don't work overall? I mean, they offer undeniable impact protection, but do not significantly improve cyclist outcomes for reasons only suspected but not yet fully known.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.

User avatar
Mick F
Spambuster
Posts: 47831
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Helmet sizing?

Postby Mick F » 27 Jan 2020, 5:32pm

Audax67 wrote:
Mick F wrote:Beat me to it!
Yes, it's circumference for (modern metric) hat sizing.

I prefer the Imperial way of diameter. I've a small head ind it's size 63/4", where most men have 67/8".


Yebbut the UK measurement assumes that your head is perfectly circular.
So does the metric system.

All it needs is Pi and a conversion to metric. Same thing in the end, but the numbers of the Imperial system are smaller.

63/4" = 17.145cm x Pi = 53.86cm

Whilst we're on the subject, my glove size is Size 10 and I take Size 9 shoes. :wink:
Mick F. Cornwall

Oldjohnw
Posts: 2893
Joined: 16 Oct 2018, 4:23am
Location: Northumberland

Re: Helmet sizing?

Postby Oldjohnw » 27 Jan 2020, 5:39pm

Mick F wrote:
Audax67 wrote:
Mick F wrote:Beat me to it!
Yes, it's circumference for (modern metric) hat sizing.

I prefer the Imperial way of diameter. I've a small head ind it's size 63/4", where most men have 67/8".


Yebbut the UK measurement assumes that your head is perfectly circular.
So does the metric system.

All it needs is Pi and a conversion to metric. Same thing in the end, but the numbers of the Imperial system are smaller.

63/4" = 17.145cm x Pi = 53.86cm

Whilst we're on the subject, my glove size is Size 10 and I take Size 9 shoes. :wink:


And whilst on the subject of size...

No, I won't.
John

User avatar
Mick F
Spambuster
Posts: 47831
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Helmet sizing?

Postby Mick F » 27 Jan 2020, 5:48pm

:lol: :lol:
Mick F. Cornwall

User avatar
tykeboy2003
Posts: 1050
Joined: 19 Jul 2010, 2:51pm
Location: Swadlincote, South Derbyshire

Re: Helmet sizing?

Postby tykeboy2003 » 27 Jan 2020, 6:14pm

mjr wrote:I think you've got more serious problems than the fit of a hat, then. Does she know they don't work overall? I mean, they offer undeniable impact protection, but do not significantly improve cyclist outcomes for reasons only suspected but not yet fully known.

I've previously explained all the reasons why I've never worn one and she admits that one would probably have made no difference 2 weeks ago but to be honest I can't bothered with the argument any more. All my kids have said they want me to wear one and virtually everyone else I've spoken to has said the same. Logic and evidence are all out the window....

User avatar
Mick F
Spambuster
Posts: 47831
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Helmet sizing?

Postby Mick F » 27 Jan 2020, 6:22pm

I agree with you and I see your issue.

I started wearing one because of "wife pressure" and "daughter pressure" back in 2005.
Put my foot down and stopped wearing one in 2015.
Mick F. Cornwall

drossall
Posts: 4682
Joined: 5 Jan 2007, 10:01pm
Location: North Hertfordshire

Re: Helmet sizing?

Postby drossall » 27 Jan 2020, 7:51pm

Audax67 wrote:Yebbut the UK measurement assumes that your head is perfectly circular. This is daft because UKsians are predominantly long-headed front to back.

+1. I've got the particular problem of a 66cm head, when most manufacturers consider 64cm to be XXL, and even then some don't make helmets that big. The few that make 66cm ones tend to make them round, so even they may not fit. My LBS spent ten years looking for one to fit me. Every now and then I'd go in for some brake blocks, they'd proudly offer me a new make of helmet, and then they'd look crest-fallen when it didn't fit. Finally they managed it, just about. Dunno whether I'd ever get another. Fortunately I only use it where it's a requirement, but that's a different discussion. Rest of the time it lives in a helmet case in a dark place, in the hope that it won't deteriorate or get damaged.

So yes, try before buy.

User avatar
Cunobelin
Posts: 9980
Joined: 6 Feb 2007, 7:22pm

Re: Helmet sizing?

Postby Cunobelin » 27 Jan 2020, 9:40pm

The evidence is that an ill-fitting helmet will actually INCREASE injury so let's start with basics.

If you buy shoes, they are all different. In one style and make you will wear a size 11, in another a 12, one will fit because it is wider then the other, and helmets are the same. The more space between you and the helmet the less efficient. Adjusting the webbing inside, or fitting pads is NOT a fix for a basically poor-fitting helmet

For example, I found Met helmets short and wide, and Giro helmets long, but narrow. Specialized fit me fine.

Also, E-Bay helmets (if genuine- there are fakes) will also only comply to the inferior EN1078 standard. A Snell B90 standard helmet has been proven to withstand greater and more diverse impacts.

Forget E-Bay, get yourself down to a good bike shop and discuss what you need, make sure that it fits well, and is comfortable. Then buy one

User avatar
Cunobelin
Posts: 9980
Joined: 6 Feb 2007, 7:22pm

Re: Helmet sizing?

Postby Cunobelin » 27 Jan 2020, 9:46pm

drossall wrote:
Audax67 wrote:Yebbut the UK measurement assumes that your head is perfectly circular. This is daft because UKsians are predominantly long-headed front to back.

+1. I've got the particular problem of a 66cm head, when most manufacturers consider 64cm to be XXL, and even then some don't make helmets that big. The few that make 66cm ones tend to make them round, so even they may not fit. My LBS spent ten years looking for one to fit me. Every now and then I'd go in for some brake blocks, they'd proudly offer me a new make of helmet, and then they'd look crest-fallen when it didn't fit. Finally they managed it, just about. Dunno whether I'd ever get another. Fortunately I only use it where it's a requirement, but that's a different discussion. Rest of the time it lives in a helmet case in a dark place, in the hope that it won't deteriorate or get damaged.

So yes, try before buy.



The Bicycle Helmet Safety Institute is based in the US, and whilst helmet advocates they do recognise there are issues they do a list of helmets for lare heads. US-based, so they may or may not be available in the UK, but gives you an idea of the options

BHSI _ Helmets for large heads