Safety issues with tubed tyres

[Anonymous]

#4390

10 Feb 14:http://www.stuff.co.nz/motoring/news/9705169/Motorcyclists-death-highlights-tubed-tyres-safety-issueThe coroner has highlighted safety issues with tubed tyres in his report into the death of a motorcyclist in 2012 . On July 20, 2012, Bryan Wyness, 71, a retired businessman living in Pukekohe, was riding his BMW motorcycle on State Highway 1 when he was killed in a crash at Rangiriri, in the northern Waikato. Wyness was riding the same BMW F 650GS touring bike that had carried him across central Asia during the famed travels of the "Silk Riders" in 2005. In a report released today, Coroner Gordon Matenga said Wyness was riding in the left of two southbound lanes travelling towards Hamilton and police had said Wyness was travelling slowly at the time of the crash. A driver of a car behind Wyness pulled out to overtake him, but at the same time the motorcycle began to drift from the left lane into the right lane, its handlebars began to wobble and Wyness lost control. The bike and its rider fell and slid into the median barrier. Wyness suffered multiple injuries including a fatal spinal injury, the coroner said. There was no collision between the motorcycle and the car, and "no evidence of a precipitating medical event". The crash is believed to have been caused by a slow air leak from the front tyre, which, upon reaching a critical point, caused the tyre walls to collapse and sudden loss of all remaining pressure in the tyre. It was discovered that the front tyre tube was as old as the eight-year-old motorcycle and "may well have been the original". The report found tubes expanded over time due to "ordinary use". In this case, the expanded tube chafed against the tyre, resulting in the leak, and ultimately the tyre's sudden deflation and Wyness's loss of control. Matenga ruled the death was "accidental". However, he recommended that a copy of the findings be sent to the New Zealand Transport Agency and ACC, and that all those who rode motorcycles in New Zealand were warned to be aware of tyre manufacturers' recommendations - if a tyre is replaced then the tube should also be replaced. "This inquest has highlighted an important safety issue for those who ride motorcycles with tubed tyres," Matenga said. "The evidence I have ... is that in Germany, America and England, if a tyre is changed on a wheel that has a tube, then the tube must also be changed. "The tyre manufacturers, Pirelli, have it written on the tyre in German. I am advised that it translates as, "New tyre, new tube." The coroner said this did not reflect the law in New Zealand. Motorcycle tyre mechanics were able to reuse the old tube when replacing worn tyres and this was "clearly a concern".

[Mark Mackay]

#18106

I Always replace with heavy duty tubes like Michelin or other h/d tubes a lot thicker and less prone to punctures off road. No need to replace as often as std tubes which are very thin by comparison.A lot more expensive but great value in the long term. Cannot put a price on safety.

[Anonymous]

#18107

So can we hear a bit more about this “median barrier”?

[Anonymous]

#18108

So can we hear a bit more about this "median barrier"?

It was a wire rope barrier...

[Anonymous]

#18109

Point taken, Gentlemen. They are great things for concentrating the motorcyclist's mind because you just don't want to go there. They can, in fact, distract you, because you keep flicking your eyes at them due to the fear factor – that breaks the “Look where you want to go” commandment.Introducing them to this thread distracts from the fact that the Coroner has highlighted a (to me, anyway) pretty damn convincing safety recommendation. Retaining control is a good way to avoid any kind of barrier. Keeping the air in your tyre helps to retain control.

---

Bwucie, ever the Devil's Advocate.

[Anonymous]

#18110

Point taken Bwucie.My only thought was whether it was hitting the median barrier that killed him and, if so, why that didn't warrant a comment from the coroner.

[Anonymous]

#18111

Wyness suffered multiple injuries including a fatal spinal injury, the coroner said. Exactly Kennif. My belief is his injuries were compounded by the cheese-cutter wire barrier. Had his fall not been interrupted by such, chances are he may still be with us. Who can find out the nature of the spinal injuries? Was he caught/snapped by a post or wire? Unlucky if it was compression if he did not highside. It was mentioned low speed and he slid into barrier!?

[Anonymous]

#18112

All agreed Hilton, and furthermore if there was NO barrier, he might have gone across the centreline and copped a head on: they tend to have dire consequences, even as bad as hitting a cheesecutter.The precipitating event was loss of control caused by rapid deflation of a tyre. The nature of the subsequent events may have exacerbated the consequences, but loss of control is not a grand thing on a motorsickle. You cannot blame the cheesecutter for the loss of control.

[Arne Rohde]

#18113

Is there a mousse or something similar available which could be pumped into the tube to maintain some semblance of rigidity in the tyre after a puncture? I know it is frowned upon to have tyre sealants inside tubeless tyres by those who have the change the tyres, but tubes are or should be discarded anyway when the tyre is replaced, so anything sticky inside the tube should have minimal effect on the process. Making tubes with multiple chambers connected only by very small holes would presumably end up being too complex and too expensive.

[Anonymous]

#18114

You don't even need tubes to cause a rapid deflation. I had an odd front tyre a little while ago. When put under enough pressure (cornering at 110, or speed above 110, like overtaking)  the bead appeared to give way and the tyre pressure dropped from full pressure to 20 odd, and if you didn't get the bike stopped fast enough, it went to zero… Was very scary when trying to pull it up on the roadside, pressure of 1 psi, and a truck bearing down behind me  😮

You cannot blame the cheesecutter for the loss of control.

Of course... but the barrier did nothing to help him, only making the situation worse than it needed to be.

[Anonymous]

#18115

two aspects involved- passive (median barriers etc) and active (rider training/diligence) safety.we have people behind bars (on a motorcycle!) and steering wheels, WITH A LICENSE, who cannot ride/drive. as long as you can pass a basic (handling) skills course you can leap into the arena. people then self learn (bad habits) and never progress to the next stage of governmental overseeing for proficiency. our RIGHT to be on the road is a difficult mindset to change. who are the "doctors" of our drivers licensing system? who will hold them accountable for the active safety (conditions of our road users)?who are the "doctors" responsible for our clogged arteries? who will hold them accountable for the passive safety (conditions of our roads)?ACC can dictate user pays, which proves life is not fair, but you still need higher maintained standards both active and passive. what is being done about people & roading conditions that are not good enough? wet bus ticket over the wrist! revenue earning disincentives! reducing the speed limit to 0kph with zero tolerance reduces the road toll, but there will still be those who flout the law and their ability, causing deaths. >:(

[Anonymous]

#18116

OK, so I'm about to light a touch paper of controversy….  Moderator/Bwucie – please feel free to slap me and tell me to start a new thread.For 5 years, I worked for a road controlling authority in a Traffic Operations Centre.  We used CCTV and traffic management systems to moderate peak traffic, respond to unplanned events on the highway, and try to preempt crashes by monitoring conditions (road, traffic, weather) that were known to have impact on safer roads.In my time:- I have watched a motorcyclists kill himself on a Z barrier post -  the rider decided to ride home after a couple of after work drinks.  At around 100kmhr, They drifted from the right lane into the right gutter, then hit the barrier and died impacting a support post, head first.- I have watched many crashes where a barrier (Jersey, Z or wire rope) saved a road user from dying by stopping them crossing into oncoming traffic- I have watched a Jersey barrier (the concrete ones) take the impact of a car at approx 160-180kmhr and direct the car into its own lane and away from the oncoming traffic.- I watched a driver lean down to play with their radio, and drift left into a wire rope barrier.  The barrier tore the bumper, left wing then left wheel off the car stopping it crossing railway lines into the path of a commuter train.- I watched a wire rope barrier stop a B train truck from crossing the centre line into oncoming traffic.Barriers work, no matter what type.But barriers, no matter what type, kill a number of motorcyclists each year.  However, this is a small percentage of what kills us.  Trees, other vehicles, other roadside furniture, natural features like banks, cliffs etc do significantly more damage.Some research on this:http://www.monash.edu.au/miri/research/reports/atsb201.pdfhttp://trafinz.org.nz/workspace/downloads/raphael-grzebieta-2-524dfcb668f97.pdfNext time you are close to a wire rope barrier, have a good look at it.  The wires are usually 20-25mm in diameter.  Twisted together, this is 50mm.  Myth Busters tired to cut a pig in half with a 25mm wire rope.  They suspended a pig carcass vertically, then stretched a wire rope horizontally like a bow string, releasing it onto the wee piggyg.  After each release of the wire rope, they increased the tension by pulling it further out.  The wipe rope was close to snapping under the strain before Myth Busters called off the test.  The result? One badly bruised pig carcass, but it was not cut in two. Cheesecutter?  Yeah nah...However, New Zealand roading authorities need to implement SAFER barriers for motorcyclists.By safer, I mean increased survivability when a motorcyclist hits a barrier.  For example:- cover exposed posts to the ground.- Use fragible plastic posts.- don't present the razor-edge of a Z Barrier to a motorcyclists.NZTA recently replaced a number of barriers on the Rimutaka Hill ( a local  Wellington ride) with a Z barrier on skinny support posts.  What they've just done is install a LOT roadside furniture that will snatch a sliding motorcyclist to an abrupt halt with unforgiving metal poles.Here endeth my 2 cents worth.My disclaimer:- I don't work for a road controlling authority.- I don't have shares in a wire rope company.- I haven't hit a barrier, and don't want to.- I'm relieved when I see a barrier that has stopped a head-on crash.

[Anonymous]

#18117

OK, so I'm about to light a touch paper of controversy….  Moderator/Bwucie – please feel free to slap me and tell me to start a new thread.

Personal Bwucie comment: What Scottmac has posted supports my own thoughts about wire rope barriers: we should not choose to hit them, that would mess us about. However, they keep us alive by doing what they are designed to do - keep out of control vehicles on their own side of the centreline, most of the time. (some do get over, depends HOW MUCH out of shape they are. if they are tumbling they can cross the barrier while airborne.)Moderator Bwucie concern about this thread: It is an open Forum, all the world can see. Out there is a family, already hurt by a bereavement, and then the process of the Coroner's Court. They could conceivably fall over this thread.The Coroner dealt with the event that caused the accident (barrier at the top of the cliff), we are discussing wire rope barriers (the ambulance at the bottom of the cliff.)Gremlin's note of caution applies to the cause, sudden deflation of a tyre: tubeless tyres can also deflate very quickly. I've seen a Blackbird do the trick with a rear tyre repeatedly - send so much through the back wheel the tyre debeads. Bad enough at the rear, when it's the front, very bad karma.

[Anonymous]

#18118

just like a truck driver is ultimately responsible for their safe load, other road users are (ir)responsible for their machines.i have to say tyres and tubes would trip me up. ain't the six monthly WOF supposed to look after me?  🙂 a special Blackbird and/or condition? unbeading a tyre surely involves incorrect something (pressures, tyre sizes or increased horsepower etc)? who is responsible? otherwise Honda might have a major on their hands.

[Anonymous]

#18119

a special Blackbird and/or condition?

Two words, Hilton, and I'll bet you will understand: Peter Stone.Crossing a gutter will do it to Jean's scoot sometimes, too. That's fun.

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