minor crash helmut advice

torturedsoul

Hi all,
Recently became re-addited to an old hobby of mine. Delighted to be back on the bike after a groin injury set me back 3 months. I do not ride with a club or in competitions (hopefully that will change), so I do not have experts or like minded people to consult with with regard to all things bicycling. Thats why I joined this forum.

Anyway after that unnecessary preamble...

I was on my bike yesterday, a new Giant defy 3 (entry level but decent for the price). I may have been a bit eager to push myself on not only icey roads, but also a bike I was unfamiliar with. I took a right hand turn at about 32Kph. The bike just collapsed on the road and took me with it. Apart from a few scratches and bruises I was ok. But my head took a really bad bang on the road. Saw stars and the like.

Is it true that you have to get a new helmut after each collision/accident?

I have read a few reports that you do!

Also I was a bit alarmed at how easy the I went over. Do I need different tyres for winter/wet conditions. Or, is there a certain angle that a road bike can not re cover from when turning?

Hope ye can give some advice..

All the best
Barry (cork area)

Beasty

First point - if you saw stars you really should see a doctor

If the helmet's taken a bang it should be replaced. There may be some weakness which you are unable to see resulting from the collision

snollup

Sorry to hear about your accident.

Regarding tyres, maybe try Continental GP4000S. I think all the lad here seem to find them good for winter. Recently started using them and so far so good.

DirkVoodoo

Tyres may be part of it, adapting your cycling to match the conditions is also important.

blorg

If you banged your head that hard then certainly you do need to replace. Anything beyond a minor scuff really.

If there is ice you will go down and it doesn't matter what your tyres or cornering technique are like. Some tyres _are_ better at grip but to be honest I don't think there are many that will make the difference between crashing or not crashing. Apart from ice, could be your technique, maybe you braked during the turn (never do this, and especially not with the front brake.)

torturedsoul

Thanks for all the advice lads. Im kind of picking things up as I go along through experiences and books/mags. Nothing beats talking to others though so all the advice is greatly appreciated.

I imagine a bit of all the replies are correct. I upscaled from a mountain bike that I was testing myself on... I was averaging about 35-50K per cycle which was what encouraged me to get a proper road bike. Hence, my technique could be all over the place alright as some of ye have said. The mountain bike tyres are so thick that I never had to deal with cornering technique before. I also may have braked, i dunno, but would be surprised if i didn't.

The tyres that came with it were Vittoria Zaffiro as far as I remember. Are they any good or are they just the bog standard tyre that come with the bike?

I am just wondering for wet conditions is it really that important to spec up on the tyre front? Or is it really just down to me and my technique?

Cheers lads.

P.S I also recently discovered Liz Hatch mmm

bcmf

+1 on the going to see a doctor if you gave your noggin a decent belt.

Skinny tyres and ice arent really good friends. Like you said it happens in a flash. If you do have to go out on the icy roads on skinnies use a very easy gear and dont lean into corners.
Vittoria's are a pretty decent tyre though a lot swear by the Conti GP4 black Chilli tyre. I have ridden these and they are indeed a great wet and dry weather tyre.

torturedsoul

I think ye might find this very interesting. I read an article about these helmets on the latest edition of Cycling plus. The basic contention is that the helmets are made from CARDBOARD and due to their structure absorbs 4 times as much impact.


"When tested against the British Standards (EN 1078) at the Imperial College, Kranium absorbs 4 times the amount of impact energy when compared to regular cycling helmets. This means that during a crash, lesser amounts of energy go into your head thus making it safer than regular cycling helmets."

Heres a link to the site, what do ye make of it? Very interesting stuff I think
http://www.anirudharao.com/index.php?/project/kranium/

tomasrojo

The ability of light bodies of expanded polystyrene to diffuse energy is indeed somewhat limited, though I don't know whether this cardboard design is an improvement.

I presume the test they allude to is the standard test, which is to drop a helmet strapped onto a 5kg headform about two metres onto an anvil. The helmet should not crack, and the polystyrene should compress. The energy generated by the fall is quite close to the energy generated by falling off a stationary bike onto your head: roughly 100 Joules.

Good description and overview here:
http://www.cyclehelmets.org/papers/c2023.pdf

The really bad brain injuries are caused by rotational forces, which cause shearing of layers of the brain. I don't believe these cardboard helmets address rotational forces. Expanded polystyrene helmets definitely only address linear forces.

A lightweight, well-ventilated helmet that could mitigate rotation of the head would be a game-altering breakthrough. I haven't heard of any plans to develop one, although the Philips helmet for motorcyclists is a start. It's probaby too heavy a design to be adapted for cylists. I haven't heard of any plans to do so.

BostonB

The roads are really cold at the moment, I suspect many tyres (especially on bikes) do not grip well in low temps unless they have a compound designed to do so. I doubt it makes much different how wide or narrow the tyre is, or what tread. its just too cold for the rubber to work. So its not really the time of the year to be testing cornering limits.

Paul Kiernan

torturedsoul wrote: »

Heres a link to the site, what do ye make of it? Very interesting stuff I think
http://www.anirudharao.com/index.php?/project/kranium/

I don't see how it would cope with gallons of sweat. Looks like it'd dissolve into mush halfway up a long climb.

seamus

BostonB wrote: »

I doubt it makes much different how wide or narrow the tyre is, or what tread. its just too cold for the rubber to work. So its not really the time of the year to be testing cornering limits.

Cold or not, the physics are the same. Wider tyres have a larger surface area touching the road and the therefore more total grip on the road. The same is true for softer tyres over harder tyres.

However you are right though - these are not the conditions to be testing how well the bike corners. Even if you have 2.5" tyres on a mountain bike, in reality you only need a 12" patch of sheet ice to turn a slight slide into an unrecoverable fall. Wider tyres will have better grip and recoverability than thinner ones, even on ice, but it's still ice.

doozerie

torturedsoul wrote:

Is it true that you have to get a new helmut after each collision/accident?

In short, yes. The polystyrene is intended to absorb a lot of the shock of the impact by compressing (and may disintegrate too). Having compressed once it may not be able to absorb as much, or any, of the shock next time round, so you should replace it after any substantial knock. So the theory goes, but it depends on how effective you believe helmet design to be in the first place i.e. whether you believe the polystyrene really has compressed at all.

BostonB

I kinda meant, I imagine on ice you need studs. Anything else is useless

http://www.peterwhitecycles.com/studdedtires.asp
http://www.bikeforums.net/showthread.php?688981-700c-Tires-Question

While you might get away with cycling on ice. You might not. Not sure its worth breaking something that take 6 weeks + to recover from. Won't do much for your fitness.

BostonB

doozerie wrote: »

In short, yes. The polystyrene is intended to absorb a lot of the shock of the impact by compressing (and may disintegrate too). Having compressed once it may not be able to absorb as much, or any, of the shock next time round, so you should replace it after any substantial knock. So the theory goes, but it depends on how effective you believe helmet design to be in the first place i.e. whether you believe the polystyrene really has compressed at all.

I cracked mine clean through with a decent fall. Not sure I'd trust that again.

tomasrojo

There is debate about whether the current liners are too stiff to compress before cracking, which, if true, would mean they are decidedly sub-optimal.

The new Australian helmet standard seems to be an attempt to address this, and to address other issues such as exacerbation of rotational forces (and, reading between the lines, perhaps indirectly the risk of strangulation for children wearing them during activities other than cycling):

http://www.inmycommunity.com.au/news-and-views/local-news/New-bike-helmets-soon-mandatory/7577035/

Public Transport Authority cycling integration manager Jim Krynen said the new helmet standard allowed for a varying density polystyrene shell.

“It provides more cushioning for the brain and straps that will stretch sufficiently in an accident to allow the helmet to come off a rider’s head after absorbing the initial impact,” he said.

“Also a redesigned visor prevents a cyclist’s head being twisted excessively when hitting the road.

“It’s critically important to wear a helmet correctly.

“Unfortunately 75 per cent of cyclists don’t.”

Oddly, old-standard helmets remain legal to use after the introduction of the new standard, but shops cannot legally sell them.

enas

As everyone said, change the helmet! (And change the spelling to the correct one ). Bear in mind that most decent helmets come with a replacement programme after a crash, where the manufacturer will replace it either for free (for rather expensive ones) or for a small fee (for most decent ones), unless it was too old I guess.

BostonB

tomasrojo wrote: »

... to address other issues such as exacerbation of rotational forces ....

Its says

...Also a redesigned visor prevents a cyclist’s head being twisted excessively...

What else in the design was changed for rotational forces? Be interested in reading more about that.

tomasrojo

I think the change to the visor is the only change related to rotational forces. That is, a new-standard helmet without a visor is no better at addressing rotational forces than an old-standard helmet without a visor. Except maybe that you mightn't be wearing the helmet during impacts subsequent to the first impact.

doozerie

BostonB wrote:

I cracked mine clean through with a decent fall. Not sure I'd trust that again.

Visual signs of damage definitely indicate the helmet should be replaced without question. The grey area is where the helmet has taken a knock but the polystyrene shows no obvious signs of having been compressed or cracked. Scratches to the surface don't count for much. Manufacturers state that it should be replaced regardless but individuals are understandably hesitant to part with a helmet that "appears" undamaged.

As mentioned by tomasrojo above, there have been questions raised about whether helmet polystyrene is actually too stiff to compress when impacted, and if this is the case then the helmet could probably "safely" be re-used after some crashes (by "safely" I mean that it'll is no less effective next time round, though whether it was ever actually safe enough in the first place is another debate entirely).

Personally, I'd replace the helmet if it had taken a hard knock, but my definition of hard knock might differ from that of others. If I was seeing stars after the knock, then that would count as a hard knock in my mind (literally). If the helmet showed no obvious signs of damage after such a knock though, I might find myself wondering whether replacing it with the same model again is actually a good idea.

Bluefoam

minor crash helmut advice

I thought you were looking for advice on what 'helmut' would be best suited to minor crashes...!

tomasrojo

tomasrojo wrote: »

A lightweight, well-ventilated helmet that could mitigate rotation of the head would be a game-altering breakthrough. I haven't heard of any plans to develop one, although the Philips helmet for motorcyclists is a start. It's probaby too heavy a design to be adapted for cylists. I haven't heard of any plans to do so.

A bicycle helmet based on the Philips system will apparently be available this year (this is from February, but I saw in a year-end round-up of cycling news).

http://www.eta.co.uk/2010/02/16/bicycle-helmet-its-own-synthetic-scalp

The bicycle helmet with its own synthetic scalp

Bicycle helmets that feature a synthetic scalp to reduce the risk of rotational head injuries are to go on sale within a year.

Existing cycle helmets are little more than polystyrene encased in a plastic shell – working in a similar way to the skull by protecting against direct blows – but they are not designed to mitigate rotational injuries, which can prove fatal.

A new design of bicycle helmets that features a synthetic scalp to reduce the risk of rotational head injuries is to go on sale within a year.

It'll be interesting to see whether they have significant take-up. Good of eta.co.uk to include a link to cyclehelmets.org for balance too.

Lumen

tomasrojo wrote: »

http://www.eta.co.uk/2010/02/16/bicycle-helmet-its-own-synthetic-scalp

If if looks like that I think I'll take the brain damage instead.