Cyclists hitting their heads on crashing

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Mick F
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Re: Cyclists hitting their heads on crashing

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rogerzilla
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Re: Cyclists hitting their heads on crashing

Post by rogerzilla »

Decades ago, we would practise crashing (on grass). The trick is to go into a roll and/or slide to spread the impact and NOT to stick a hand out, which will usually break your collarbone. It's worked for me in some quite high speed prangs, mainly off-road. However, if your front wheel is swallowed by a pothole or you are struck from behind, you won't have time to react.
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Re: Cyclists hitting their heads on crashing

Post by Jon in Sweden »

pjclinch wrote: 28 Feb 2023, 2:33pm
I'd seen a story like this online on Usenet and wasn't sure whether I should believe it, and then I experienced it in person...

Turned up at school on the triplet to pick up the kids, while waiting noticed a bike another parent had taken in for their child to ride home on had one of the brakes unhooked so I pointed it out. And he'd deliberately unhooked it because it was rubbing but felt it didn't matter because - you've guessed it - their child had a helmet.

Pete.
Helmets can't fix stupid unfortunately.

I cycled a lot as a teenager and again now the last year. I had a handful of spills as a kid (a couple of times on ice, hit by cars twice and a pedestrian once) and I didn't ever land on my head. I did once have the wingmirror of the car that hit me land on my head. Might have hurt more if I'd not had a helmet on.

I've had one fall this winter on ice and landed on my chin. Three stitches but otherwise fine.

Regardless, my head is important to me and I want it protected. As such, when out on training rides, I wear a helmet. I don't generally wear a helmet when on the town bike bumbling around the village. The exception to that is when it's properly snowy or icy.

The reason I make the distinction is that when on training rides, I'm on higher speed limit roads going at a much higher speed. When I'm in the village, my speed is low and the speed limits are 30 or 40kph. Consequently the risk is far lower for me.

Either way, both my children wear helmets all the time and I will encourage them to do so once they're old enough to make that decision themselves.

I do not accept that not wearing a helmet lowers the risk of injury in any way. It's akin to suggesting that seat belts reduce risk in a car crash. Codswallop! :shock:
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Re: Cyclists hitting their heads on crashing

Post by Cowsham »

rogerzilla wrote: 24 Mar 2023, 10:00pm Decades ago, we would practise crashing (on grass). The trick is to go into a roll and/or slide to spread the impact and NOT to stick a hand out, which will usually break your collarbone. It's worked for me in some quite high speed prangs, mainly off-road. However, if your front wheel is swallowed by a pothole or you are struck from behind, you won't have time to react.

I hit a pothole at about 25MPH but so did my son on his bike in front of me. As he slowed my front wheel got levered over his rear wheel flipping the bike upside down. I only had time to turn my left elbow out which met the ground. The loud snap I heard in my left ear was my collarbone breaking an inch from the distal end along with the acromiom process bone on the other side of the ac joint. Then because my arm was pushed up I landed heavily on my now exposed left side breaking 7 ribs. My elbow was not broken just scuffed and bruised. Breathing was difficult for a while. Not sure if my head touched the ground or not in that crash but it probably prevented a much worse injury in the crash before that.
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Re: Cyclists hitting their heads on crashing

Post by rogerzilla »

Nasty. Tyler Hamilton would have carried on with the ride, but I suppose he would have been on drugs :D
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Re: Cyclists hitting their heads on crashing

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rogerzilla wrote: 1 Apr 2023, 8:43am Nasty. Tyler Hamilton would have carried on with the ride, but I suppose he would have been on drugs :D
I needed a morphine kazoo just to get me in the ambulance.
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Re: Cyclists hitting their heads on crashing

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Stuart Easton motorcycle racer.was told by another motorcycle racer " if you fall and are badly injured just ask for special K " ( ketamine a very powerful pain reliever )

The marshal first on the scene of Stuarts first really bad crash said to the the travelling doctor " he's in a lot of pain but wants cereal ? " :lol:
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Re: Cyclists hitting their heads on crashing

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Jon in Sweden » 1 Apr 2023, 7:09am wrote
I do not accept that not wearing a helmet lowers the risk of injury in any way. It's akin to suggesting that seat belts reduce risk in a car crash.
Ignoring seat belts.
Cowsham » 1 Apr 2023, 8:37am
I hit a pothole at about 25MPH but so did my son on his bike in front of me
https://www.mbr.co.uk/buyers_guide/moun ... ets-394092
747 grams

Hitting deep pot holes can incur g forces up to 10g. So a 747 gram helmet can add extra forces for going over the handlebars. Without a helmet the forces exerted could be reduced. The risk of falling or going over than bars is reduced by not wearing a helmet, when hitting deep potholes. see
https://www.researchgate.net/publicatio ... _stability
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Re: Cyclists hitting their heads on crashing

Post by Cowsham »

Steady rider wrote: 1 Apr 2023, 4:48pm Jon in Sweden » 1 Apr 2023, 7:09am wrote
I do not accept that not wearing a helmet lowers the risk of injury in any way. It's akin to suggesting that seat belts reduce risk in a car crash.
Ignoring seat belts.
Cowsham » 1 Apr 2023, 8:37am
I hit a pothole at about 25MPH but so did my son on his bike in front of me
https://www.mbr.co.uk/buyers_guide/moun ... ets-394092
747 grams

Hitting deep pot holes can incur g forces up to 10g. So a 747 gram helmet can add extra forces for going over the handlebars. Without a helmet the forces exerted could be reduced. The risk of falling or going over than bars is reduced by not wearing a helmet, when hitting deep potholes. see
https://www.researchgate.net/publicatio ... _stability
Your getting a bit mixed up there steady. I didn't go over the handlebars. The bike got flipped upside down while doing 25MPH ie like an axial roll or an aileron roll which is why I hit the ground so hard. It wasn't due to me hitting the pothole it was due to my son hitting it first and slowing then me being too close ( lesson one ) and hitting the pothole resulting in my front wheel going down the outside of his rear wheel then getting levered up and over his rear wheel. All that happened in half a second. When something like that happens you're glad to have a helmet on.

Imagine having an impact that hard, breaking so many ribs and being knocked out as well. I had to work hard to get that first breath.
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Re: Cyclists hitting their heads on crashing

Post by Steady rider »

Thanks for making it clearer. The link provided some figures for hitting potholes,
Pot-holes if not seen prior to impact, may result higher actual forces because the reaction force could apply within about 0.04 seconds compared with a quick reaction time of about 0.1 seconds, i.e. at 8m/s crossing a pot-hole of 300mm would take about 0.0375 seconds.


(3) (PDF) Suggested research to evaluate cycle helmet effects on balance and riding stability. Available from: https://www.researchgate.net/publicatio ... _stability [accessed Apr 01 2023].

Sounds like you may have incurred side forces from the impact.
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Re: Cyclists hitting their heads on crashing

Post by axel_knutt »

Jon in Sweden wrote: 1 Apr 2023, 7:09am I do not accept that not wearing a helmet lowers the risk of injury in any way. It's akin to suggesting that seat belts reduce risk in a car crash. Codswallop! :shock:
The odds of being involved in an accident resulting in an injury were 118% (OR = 2.18; 95% CI = 1.22, 3.89) higher among helmet users than among nonusers.

Motorists wearing seat belts drive faster.
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Re: Cyclists hitting their heads on crashing

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Jon in Sweden wrote: 1 Apr 2023, 7:09amThe reason I make the distinction is that when on training rides, I'm on higher speed limit roads going at a much higher speed. When I'm in the village, my speed is low and the speed limits are 30 or 40kph. Consequently the risk is far lower for me.
I still find that logic difficult. Helmets are designed and tested for the forces associated with falling off sideways from a standing start. By the time your head hits the ground, it's probably doing about 10mph. Since most of the "interesting" things in a crash relate more to the square of speed than the speed itself, a rough approximation, and making the assumption of a direct impact, says that 40kph=25mph is exceeding the design parameters of the helmet by 6.25 times.

I'd find it much easier to understand people arguing for helmets at low speed and questioning their value at high, just as I'd find it really weird if soldiers were to decline bullet-proof vests in gun battles and then insist on them for tank fire.
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Re: Cyclists hitting their heads on crashing

Post by Jon in Sweden »

axel_knutt wrote: 2 Apr 2023, 12:04am
Jon in Sweden wrote: 1 Apr 2023, 7:09am I do not accept that not wearing a helmet lowers the risk of injury in any way. It's akin to suggesting that seat belts reduce risk in a car crash. Codswallop! :shock:
The odds of being involved in an accident resulting in an injury were 118% (OR = 2.18; 95% CI = 1.22, 3.89) higher among helmet users than among nonusers.

Motorists wearing seat belts drive faster.
I don't accept that logic. I don't utilise a helmet as anything other than a line of protection of last resort. I really hate falling off my bike and I'm much more cautious than most on the bike. For that reason, despite having exceptional mountain biking trails around here, I generally stick to road and gravel.
drossall wrote: 2 Apr 2023, 12:27am
Jon in Sweden wrote: 1 Apr 2023, 7:09amThe reason I make the distinction is that when on training rides, I'm on higher speed limit roads going at a much higher speed. When I'm in the village, my speed is low and the speed limits are 30 or 40kph. Consequently the risk is far lower for me.
I still find that logic difficult. Helmets are designed and tested for the forces associated with falling off sideways from a standing start. By the time your head hits the ground, it's probably doing about 10mph. Since most of the "interesting" things in a crash relate more to the square of speed than the speed itself, a rough approximation, and making the assumption of a direct impact, says that 40kph=25mph is exceeding the design parameters of the helmet by 6.25 times.

I'd find it much easier to understand people arguing for helmets at low speed and questioning their value at high, just as I'd find it really weird if soldiers were to decline bullet-proof vests in gun battles and then insist on them for tank fire.
I do not feel exposed or at risk within the village. We have wide, open roads with good visibility, good road surfaces and respectful motorists going a maximum of 40kph. If there are (as I mentioned) complicating factors such as snow or ice, I tend to wear a helmet. But otherwise I don't.
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Re: Cyclists hitting their heads on crashing

Post by tim-b »

Hitting deep pot holes can incur g forces up to 10g. So a 747 gram helmet can add extra forces for going over the handlebars. Without a helmet the forces exerted could be reduced
@Steady rider
You're skewing the figures. My road helmet weighs around 230g (manufacturer's figure), cost under £20 and I'd suggest is more representative of a commonly-used road helmet than the helmet you quote which weighs more than 3x that and is designed for bike park riding, enduro and downhill racing. Bike park as in Bike Park Wales, etc, https://www.bikeparkwales.com/media/Tra ... 0PRINT.pdf (see the red, black and purple pro-line trails)

The "can" and "could" isn't convincing either :)
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Re: Cyclists hitting their heads on crashing

Post by Steady rider »

Jon in Sweden » 1 Apr 2023, 7:09am wrote
I do not accept that not wearing a helmet lowers the risk of injury in any way
I used the heavy helmet to illustrate the forces that have been reported from testing helmets, up to 65N or 14 lbf.
The link I provided also calculates for lighter helmets. At 250 grams and 10g, about 20 N or 4 lbf.
A recent article details g forces from slow cycling speedsincurring up to 6g acceleration forces3. A lightweight helmet at 0.25 kg incurring a4g acceleration would involve a force of about 10N or 2.2 lbs force imperial.


(3) (PDF) Suggested research to evaluate cycle helmet effects on balance and riding stability. Available from: https://www.researchgate.net/publicatio ... _stability [accessed Apr 02 2023].

There are reports detailing the level of accelerations from normal road cycling. The additional forces stem from wearing helmets, so extra falls can be expected.
Last edited by Steady rider on 2 Apr 2023, 7:51pm, edited 1 time in total.
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