Does your riding position influence the chances of head injury?

[mattheus]

Here's a recumbent, conventional supine compact long wheel base BikeE, and I hope this illustrates that the position one rides in is not an absolute indicator of chances of a crash and how/where the bike is ridden will be a factor too.



No spoiler that he doesn't crash, but was it less likely to have happened with head impact than if he was on, say, a downhill MTB?

Pete.

Great film. I like his gloves.

[bjlabuk]

That's according to the WHPVA. According to the UCI recumbents aren't proper cycles at all... unless you're a handcyclist.
The WHPVA are, like the UCI, creating categories for their particular events, not formally defining things to some ISO standard.
Pete.

I wasn't the one who started talking about the type of recumbent, rather than the riding position (you and Blondie were).

But seeing as you mention the ISO, this is from ISO 4210-1:2023(en) Cycles — Safety requirements for bicycles —
Part 1: Vocabulary

https://cdn.standards.iteh.ai/samples/7 ... -2023.pdf

3.1.7
recumbent bicycle
bicycle (3.1.1) that places the rider in a laid-back reclining position


So I agree with Blondie and the ISO and the WHPVA with regards what a recumbent bicycle is. But lets get back to riding position rather than disagree over definitions of types of bicycles.

[Blondie]

Did not have a head impact on the recumbent did he? There are many collisions between cycles and walls, cars etc where on a road bike you’d do well to avoid hitting your head or going over the bonnet (of a car). In the case of a recumbent you’d have to be trying very hard to hit your head or go over the bonnet. It’s simple physics combined with body position.

[pjclinch]

Did not have a head impact on the recumbent did he? There are many collisions between cycles and walls, cars etc where on a road bike you’d do well to avoid hitting your head or going over the bonnet (of a car). In the case of a recumbent you’d have to be trying very hard to hit your head or go over the bonnet. It’s simple physics combined with body position.

That only goes for a single mode of crash though. The great majority of UPDs I've had on both the 'bent and the upwrongs have been to the side. On the one hand a 'bent is typically lower so you're not falling as far sideways, but there again going along on my Streetmachine my head isn't actually significantly lower than a roadie in a full aero tuck, and the ability to move around out of the seat arguably gives less chance of keeling over at low speed on an upwrong. Not a smoking gun, but arguable.

And while I personally don't believe 'bents get hit by other vehicles any more than upwrongs I don't have solid evidence to back that up.

I'm completely on board with the idea that over-the-bars incidents are fewer on a 'bent if all else is equal (I've often suggested I think they're better in that respect based on > 20 years of riding them) but that's not the same as clearly reducing the chances of head injury in any mode of crash. That I think that all else being equal I'm less likely to go over the bars on the 'bent is very much part of why I do technical road descents significantly faster, soaking off all that increased perceived safety.

(Only really nasty prang I've ever had was when a car spinning out from a collision picked me up sat waiting in a side road. I was on my recumbent, not actually moving. Off work for two weeks with concussion. The car that hit me didn't seem to have much respect for the idea that I'd not be hitting be hitting my head and I wasn't trying at all...)

Pete.

[853]

I'm completely on board with the idea that over-the-bars incidents are fewer on a 'bent if all else is equal (I've often suggested I think they're better in that respect based on > 20 years of riding them) but that's not the same as clearly reducing the chances of head injury in any mode of crash. That I think that all else being equal I'm less likely to go over the bars on the 'bent is very much part of why I do technical road descents significantly faster, soaking off all that increased perceived safety.

I can recall five over-the-bars incidents (it's not something you forget), yet none of them resulted in my hitting my head on the ground or on anything else. The first incident was so long ago I was on my kids bike with 24" wheels (I think), whilst the latter ones were on 27" and 700c wheels and road bikes. From my experience, at slower speeds (I would estimate below 17mph) I was thrown onto the 'bars - such that I got severe bruising on my lower ribs*. For such incidents at a slightly faster speed (not much more than 17mph I would guess) I was thrown clear, and did a partial somersault and landed on my back - and I've done this twice. The physics of it will depend on the speed, and how solid the impact was, amongst other things.

From what I've read 'bents are faster on downhills, and probably on the flat too for the same rider power output. Although 'bents may have a higher over-the-bars speed point, I have every reason to believe that they would behave in the same way at a certain (slightly higher) speed.

*And before anyone thinks being thrown over the 'bars, and your lower ribs landing on the 'bars, is a safer outcome than being thrown over completely, I should point out that when this does happen the stem goes into your groin. And those narrow old-style quill stems do hurt a lot when they hit you at 15mph.

[pjclinch]

From what I've read 'bents are faster on downhills, and probably on the flat too for the same rider power output. Although 'bents may have a higher over-the-bars speed point, I have every reason to believe that they would behave in the same way at a certain (slightly higher) speed.

Speed is a lot down to particular design and implementation. Mine (a tourer) isn't particularly whizzy but if you get one built for speed it can go very fast on downhills and on the flat (the LEJoG cycling record has been held by a faired recumbent trike for quite a long time). Going downhill on my touring 'bent I'm not either lower or quicker than a roadie in a full aero tuck, but if you put in some potholed corners I've got 40mm tyres and full suspension where your roadie typically doesn't so that's where I leave my drop-barred compatriots behind.
(And this also shows that "a recumbent" isn't a distinct class, any more than "upright", so it's stretching things a bit to assume that all recumbents will be similarly liable/not liable to certain crash modes.)

*And before anyone thinks being thrown over the 'bars, and your lower ribs landing on the 'bars, is a safer outcome than being thrown over completely, I should point out that when this does happen the stem goes into your groin. And those narrow old-style quill stems do hurt a lot when they hit you at 15mph.

This is a good point. Even if a head is hit going over the bars It's not necessarily the case that head injury is surely worse than other injury (seeing stars for a minute and needing to sit down is a "traumatic brain injury", arguably preferable to several broken ribs), and the best way of avoiding head injury is the same as avoiding other injury: avoid crashes.

Pete.

[cycle tramp]

The against (compulsory) helmets tend to use arguments drawn from statistics the Germany and the Netherlands.. those for (compulsory) helmets tend to draw statistics from other countries...

Just for the record, I would question this premise. Those questioning the case for helmets do point out that casualties are low in the Netherlands and, possibly, Germany. Those arguing for compulsory helmets do not obviously look at other countries for statistics. It's not really about where the figures come from.

A more accurate statement would, I think, say that the case for helmets is itself made more strongly in the Anglophone countries, reflecting a difference of approach to cycling and safety. Also, the case for helmets more often (though far from always) assumes that the statistics are bad without actually checking into the detail. But neither side is cherry-picking by country in quite the way that you imply.

By definition, I would question anything I'd write... however in defence of my earlier statement, I was thinking of the situation by which someone who occupies the public's mind falls from their bike, and then posts that everyone should wear a helmet. On a particular slow news day, this is then picked up by a journalist who then uses data from another country to support this view- if they are a more well 'rounded journalist they will include other views from other people who will use data from other countries... for example I give you this piece of writing from the mail https://www.google.com/amp/s/www.dailym ... erous.html
There's the usual helmet-whataboutry in there and the argument fails to move forward.....

[cycle tramp]

Probably a more accurate piece of journalism in regards to Gordon Ramsey's helmet claim..
https://bikesnobnyc.com/2024/06/17/big- ... s-tribute/
..and in the subtext raises the question that perhaps Gordon Ramsey should concentrate on riding his bike at a speed which is in his limits to control and less about what we all have on our heads...

[cycle tramp]

We need to keep in mind that any connection with riding position is entirely speculative, and no evidence whatever has been offered. It would also be extremely hard to demonstrate.

Well.. that's probably because no evidence exists, either for motorcycles or bicycles... and whilst it would be entertaining to fix a number of crash test dummies onto bikes, and motorcycles before freewheeling them in car doors, hedges, rocks, trees, lamp posts, walls...its also gonna be expensive... I think Starmer said that we can have a quid this year to pay for UK bike facilities... let's not waste it....

...At best you'd end up with percentile figures such as 'your chances of hitting your head whilst looking like a mating frog on your road bike increase to 34% compared to 13% if you pretend to be Peter Fonda whilst riding a recumbent"...
Which might mean that road cyclists get helmet ads, and recumbent riders get rubber floating arm bands ads, incase they fall sideways and might bruise their upper arms, or perhaps as protection against really deep puddles...

But these figures miss out one important factor... if you ride in a position which allows you to see clearly all the way around you, then you are more likely not to be involved in any sort of incident for which you would need a bike helmet

..by the way, if you repeat my name three times whilst looking in a mirror, I return to this forum... hey, who knew?

[cycle tramp]

Ah....
I think it goes anecdote, hypothesis, experimentation and then conclusive evidence..

..it worked for Newton..

[pjclinch]

Ah....
I think it goes anecdote, hypothesis, experimentation and then conclusive evidence..

..it worked for Newton..

Though even he managed to get it worng at times. He was quite keen on alchemy!

Pete.

[853]

But these figures miss out one important factor... if you ride in a position which allows you to see clearly all the way around you, then you are more likely not to be involved in any sort of incident for which you would need a bike helmet

Do have any evidence of this, or is this just your opinion?

[cycle tramp]

Tractor driving.... if I'm driving a tractor, I get a better view of the on coming traffic and road conditions and I am less likely to be surprised by either..

Second to the tractors sitting position is my bike, with the handlebars set a few inches higher than the saddle... I'm at eye level with van and 4x4 drivers and stare down into sports cars.. it still allows me to see over cars and I can pick out road defects..

....possibly the worst is my own small car, the seating position is lower than the above, and I have to look around parked cars instead over over them... and as such I'm more likely to be surprised...

[pjclinch]

I would suggest that there are sufficient differences between tractor driving and bike riding that it's not clear cut that assumptions about one will hold for the other. For example, one is small and manoeuvrable and the other isn't, so style of control may be quite different.
And while I personally prefer an upright sitting position to a sporty crouch for the better all-around pilot view we tend to come back to people that perceive they're safer paying less attention: risk compensation at work.

Also I'd guess it may well be the case that some bikes/riding positions are better suited to some conditions than others. My 'bent is significantly less nippy in traffic than my Brom and Moulton and the pilot view tends to be worse in dense traffic too, so is that bad? It means I tend to just join the queue rather than filter, and filtering increases risks...

Conjecture is good for a start point, but not an end one.

Pete.

[cycle tramp]

I would suggest that there are sufficient differences between tractor driving and bike riding that it's not clear cut that assumptions about one will hold for the other.

Conjecture is good for a start point, but not an end one.

Pete.

Well, unless I can find any participants to the following experiment, it's going to have to do;
Participant a was asked to ride a bike for one hour, through town at rush hour and out into the open countryside.
Participant b was asked to ride the same bike, at the same time, following the same route - but they were asked to wear glasses of which the upper 40% of the lens was masked out.

..given the choice, would you be a or b in this experiment?

..going back to the whole Gordon Ramsey thing... its possible that it was a mixture of his speed and limited visibility caused by his cycling position which caused him to crash..
..the only figures there are may come from the Netherlands where alot more 'sit up' bikes are used. However their low rate if cycling injury has already been attributed to cycle facilities.. personally I believe its a mixture of both.. but it's impossible to prove...