Motorcycle and Bicycle Crash Analysis – Wobble, Weave and
Capsize

Motorcycles and bicycles stay upright for the same reasons,
so they also crash for the same reasons. This is true despite their difference
in weight and the difference in the speed at which they commonly travel. Although
the rule holds true for crashes which involve two wheeled cycles  and other participants such as pedestrians
and other drivers, in this discussion we are talking only about crashes that
involve a bike, unaffected by the actions of people other than the rider and
any passenger who may be aboard.

The most simple form of bike crash is called a capsize. It
happens when the center of gravity of the bike and rider get so far outside of
the contact points between the tires and the ground that the operator cannot
overcome the force of gravity. A capsize is really just a form of falling over
sideways. As simple as it is, understanding the basics of the capsize is
necessary to understanding the more complex forms of crash.

The three critical components of the capsize are the two
places where the tires meet the road and the one single point where the center
of gravity of the rider/bike combination is located. Starting with a non-moving
two-wheeled bike standing straight up with a single rider, it is easy to
visualize these three components. The places where the tires meet the road will
be patches that are roughly square. They are where tires are slightly squashed
against the pavement, and are roughly square because gravity pulls the bike and
rider down and the compressed air pumped into the tires is, by design, not
powerful enough to maintain perfect roundness of the tires. The force of the air
in the tires makes them hard enough to avoid going entirely flat, but soft
enough to provide a cushioned ride, so the tires go slightly flat and are
slightly spread out on the road. Theoretically, the two contact patches are of
equal size, as both tires share the burden of holding everything up. However,
assuming that the tire pressures are equal but the rear of the bike is loaded
more heavily than the front, the rear contact patch is probably a little bigger
than the front one. Also, assuming that the combined weight of the bike and
rider is evenly distributed to the left and right, the tire/road contact patches
will be centered on the front-to-back centerline of the bike.

Having visualized the two tire/road contact patches, the
center of gravity is remains to be considered.  The center of gravity is the point around
which the combined bike/rider would balance in every direction if the
combination could be supported there (which can only occur in theory). To visualize
it, consider any two-wheeled bike sitting on a flat roadway and viewed from the
side. The left/right position of the center of gravity will be close enough to
the middle of the space between the two wheels (or road contact patches) that
there is no chance of the bike tipping over frontwards or backwards (not so
with a unicycle!). Considered from the front or rear, the center of gravity of
this bike will be directly above the bike’s front-to-back centerline (if you
suspended a lead weight from the center of gravity, it would hang straight down
to the left/right centerline of the bike). As long as gravity is pulling the
rider/bike straight down on the front-to-back centerline of, the gravitational
pull will be aligned with and resisted by the two road/tire contact patches and
the bike will stay upright. If the rider leans left, he or she moves the center
of gravity to the left of the front-to-back centerline of the road/tire contact
patches, and the contact patches can no longer overcome the pull of gravity.
The rider will have to put his left foot down, or the bike will fall over in a
capsize.

Beyond a bike capsize from a stationary position, the
mechanism of single bicycle and motorcycle crashes get more complicated fast. The
same three components, two road/tire contact patches and the center of gravity
of the bike/rider, are the critical factors, but there is a lot of changing
going on with a moving bike.

For example, when the bike is still, the shape and size of
the road/tire contact patches does not change. When the bike is in motion, it
changes constantly. When the bike accelerates, the load on the front wheel
drops (which is what makes the “wheelie” possible). As the load on the front
wheel drops, the rear contact patch gets bigger and the front contact point gets
smaller (until, in a wheelie, there is no front contact patch at all). When the
bike leans to the right, the contact patches move to the right (part way up the
sidewall, similar to what happens when a sailboat heels- that part of the hull
which is supports a heeling boat is different than that which supports a boat at
rest). The angle of lean (or heel) and the front/back weight distribution are
just two things that affect the size and shape of the contact patch. Wind and the
hardness, flatness, roughness, and stickiness of the road surface, which also
vary constantly, all change the shape of the road/tire contact patches and
affect the stability of the bike.

Wobble and weave are two specific forms of instability which
are characteristic and virtually unavoidable in two wheel bikes and
motorcycles. They will be explained in more detail later.

Few motorcyclists or bicyclists think about or understand
the dynamics of capsize, wobble or weave, but they all have an instinct as to
how to manage them to avoid crashing. When a crash does occur, an engineer or
other expert may be called upon to re-create or reconstruct the events leading
to the crash. Did the bike go down strictly due to operator error, or was a
defect in a tire,  or the design of the bike
play a significant role? If wind and road conditions play a part in a bike
tipping over, it is not hard to see that fork construction, tire performance
and bike suspension also play a big role. A crash reconstructionist must be
prepared to analyze all of these factors, as well as issues of maintenance and
repair, to be able to explain the cause of a bike or motorcycle crash.

If you or a close friend or loved one have been hurt in a bike
crash, be sure that your case is evaluated by an engineer and an attorney who can
identify the factors that lead to crashes and properly analyze them. At Berman
& Simmons, we have the experience, resources and will to understand your
case and to pursue all of the remedies that are available under the law. We are
happy to answer your questions about your potential case and our expertise. All
of our work is done on a contingent fee basis, which means that there is no
cost to you unless and until we win.

If you or someone you love has been injured in a riding mower accident, call Berman and Simmons to discuss what happened. We have handled these cases before, and are able to quickly examine the mower and the location where the injury happened and advise you about possible legal rights and remedies. We can also quickly arrange for an engineer or other lawn mower expert to assist in reviewing the case. Either way, we would be glad to assist you by sharing our expertise, experience and insight. All of our work is done on a contingent fee basis, so there is no charge unless or until we are successful. Call our toll free number 1-800-244-3576 is our toll free number or visit our website www.bermansimmons.com to learn more about our work and our lawyers. We are easy to talk to and ready to help.

In one case, a person suffered a head injury due to a defective handle design on a garden cart. The cart was purchased in pieces with assembly instructions. The handle (a bracked-shaped part when viewed from above: [ ) was made of tubular steel and designed to slide into brackets, one  bolted to each side of the cart. The design anticipated that the user would grip the long side  of the handle (the vertical portion illustrated above) and push the cart in front of him or her.  As long as the user pushed the cart, the tubular steel handle pressed harder into the brackets.  However, the designer did not provide bolts, screws or other fasteners to restrain the handle in the brackets, so when the user pulled backwards on the handle with a heavy load in the cart, the handle pulled out of the brackets and came free in the client’s hand. The client fell and suffered a serious injury because the defect in the design. It was entirely foreseeable that a user would pull backwards on the cart, and that someone might lose balance and get hurt. The need to fasten the handle would have been obvious to either a thoughtful designer or any safety engineer who reviewed the design, and manufacturers have a duty to eliminate obvious and unnecessary hazards from their products.

Another of my handle failure cases involved the pull strap on an overhead door on the back of a delivery truck. The back doors of such trucks are generally made in hinged panels mounted on rollers so they can roll up on tracks, one mounted on each side of the door opening  at the back of the truck. There is usually a spring provided with such doors to assist in the  task of opening them because they are too heavy for a person to lift alone.  Even with a spring assist for lifting, roll up truck doors are heavy. To keep the weight down, manufacturers commonly make them by sandwiching a lightweight core between a rigid matierial such as plywood on the inside and a light weight weatherproof aluminum on the outside. The sandwich is held together with rivets which sometimes pop apart. Rivet failure in the door sandwich is not such a bad problem becuase there are many rivets, the rollers on each outside edge of the doors are bolted on, and the loosening of the sandwich is not likely to cause injury. The problem arises when the same rivets are used to fasten the handle  (usually a metal plate and a nylon strap)  used for pulling the door up and down. When an unsuspecting worker standing on the narrow rear shelf of the truck pulls on the strap to raise or lower the door, his or her balance depends on the strap staying in place. When the strap comes loose, the worker is highly likely to fall off the truck. Serious injuries occur when people fall from three or four feet onto cement or paved parking lots.

Another sort of handle failure case is reflected in a recent product recall. See  the article at http://www.cpsc.gov/cpscpub/prerel/prhtml10/10157.html.  The Consumer Products Safety Commission and the manufacturer have recalled a machete due to the risk that the handle grip is inadequate and unsafe. While using this particular machete, it is possible for one’s hand to slip off the handle forward onto the blade. Since the blades are razor sharp, this can result in  severe laceration. A properly designed handle would provide a “stop” to prevent the hand from sliding forward, or at least to deflect the hand and fingers away from the blade should a slipping accident occur.

These are just three examples of ways that poor handle design can cause injuries. There are many more circumstances in which severe and catastrophic injuries can result from handle failure or poor design.

If you or someone you know falls, suffers a severe cut or is otherwise hurt due to a poorly designed or defectively fastened handle, you should immediately preserve any and all available evidence. The handle itself and all related hardware, especially failed rivets, nuts or bolts, warnings and instructions, and photographs of such evidence as the truck door described above (which showed a pattern of rivet failure) are very important. Making the evidence available to an engineer, or at least a lawyer with  experience in such cases, can mean the difference between success and failure in the case. Without specific evidence demonstrating the conditions under which the handle failed and why it should not have failed, it may be impossible to prove the case.

You are always welcome to consult with Berman and Simmons free of charge on any personal injury case. If we decide that we can help, and if you choose to hire us, we will handle the case on a contingent fee basis, which means that we will not be paid unless we win. When we settle the case or win at trial, our fee will be a percentage of the recovery. 

Twenty years ago, NHTSA, the federal government agency charged with overseeing vehicle safety, changed the official name of the child’s car seat from “child restraint system” to “child safety seat.”  Every parent and grandparent will tell you that child safety is what they expect when they buy and use these special seats.  But what is the difference between child restraint and child safety?

Child safety in a car seat starts with the idea of restraint. First the seat must be restrained in the car and then the child must be restrained in the seat.

The safest way to restrain a child’s car seat is to belt or tether it to the vehicle at both the base and the top.  Child seats that are not designed to be secured top and bottom are more likely to move within the car during a crash. This creates obvious and avoidable risks of injury.

When it comes to restraining the child in the seat, studies show that the safest approach is the five point harness, which secures the child across both shoulders, both hips, and at the crotch. Other restraint systems, including the three point harness, the tray shield, and the T-shield, are not as effective because they both allow more movement within the seat and increase the risk that a child will strike a sharp edge or a hard object during a crash. 

Child safety does not stop with a good restraint system. A good car seat will also be rugged enough so that it does not break or bend too much during a crash event and will have adequate padding so the when the child is thrown against the seat back or sides (or suspended upside down)  during a crash event the crash forces will be soft enough that no injury occurs.

Attention to padding and seat integrity in child car seats are extensions of the concepts of crashworthiness which have dramatically altered all aspects of automobile design since the advent of the seatbelt. Cars are much safer today, and child seats should be also. Recognition of this fact was the driving force behind the name change from “child restraint system” to “child safety seat.”  

A car seat that does not have adequate straps to hold the seat securely in the car or the child securely in the seat, or which allows a child to suffer lacerations or head or neck injury  in a crash may be a defective product.

If you or someone you know believes that a child’s car seat did not perform as a safety seat should, you should promptly contact to a lawyer who understands crashworthiness cases. It is very important to move quickly to secure and protect all of the critical evidence so that the case can be fully and properly evaluated.

John Sedgewick and Berman and Simmons have handled such cases, mostly in Maine but also in other states. Mr. Sedgewick is listed in Best Lawyers in America under the Plaintiff’s Product Liability section, and Berman and Simmons has been named by U.S. New and World Report as Maine’s best Plaintiff’s Product Liability law firm.

In the context of information exchange in a lawsuit, called discovery in civil cases, defendants often exaggerate the scope of information they claim to be a trade secret and demand that  plaintiff keep the information hidden as condition of producing it. For example, if a component part of a machine has been modified to eliminate a defect, the manufacturer may claim that the new design is a  trade secret which should be kept from the public. However,  legimate trade secret protection does not to extend to information that has been otherwise publicized.  Replacement parts on equipment sold publicly can be seen, measured and tested by anyone who is aware that the parts are present. The only benefit to keeping details about replacement parts secret is that people injured by the prior version of the product may not realize that they were injured by a defect that has now been eliminated from the product. This kind of secret is not what the law or the courts intend to protect.

In the context of settlement, the secrecy problem is worse.  Once plaintiff has gone to the expense and trouble of bringing a lawsuit to convince the defendant that he or she can prove the product to be defective, and after trying to defeat the plaintiff in every way possible, the defendant may agree to settle.  Often, such settlement agreements are conditioned on the plaintiff’s promise of secrecy and the demand that all evidence of defect, all proof such as test results, alternative designs, deposition transcripts, expert reports, and damaging photographs, be destroyed. In such cases, an injured plaintiff’s resources and energy may be exhausted and the will to fight for the protection of other victims may be overcome by the need for peace,  the need for resolution of conflict, and, frankly, the need for settlement money. At that point, there is no one looking out for the public interest in the free flow of information. The defendant often takes advantage of its market power and clamps a demand for secrecy on all that the plaintiff has learned.

Individual plaintiffs have a hard time fighting for the broader public interest in limiting confidentiality orders and secrecy demands to information which can legitimately be labeled secret. Protecting the broader public interest requires the attention and efforts of those of us not directly involved as parties to a particular case. To join the fight against secrecy in litigation,  read the postings on the dangers of excessive court secrecy at www.publicjustice.net

Public Justice is a great organization dedicated to protecting every individual’s right to access to the courts and the information that flows from enforcement of individual rights. It is one of the leaders in the fight against courtroom secrecy.  You can join the fight against secrecy by supporting Public Justice or by joining as a member.

If you talk with other lawyers about us, they will say:

- Berman and Simmons has more experience representing injured people in products liability cases than any other firm in the state;

- Berman and Simmons has more resources available to help people injured by defective products liability than any other firm in the state;

- Berman and Simmons has more jury trial experience in personal injury cases than any other firm in the state.

If you would rather settle your case than go to trial, why do you need an experienced trial lawyer?

- Although most personal injury cases settle before trial, insurance companies and their lawyers know which lawyers are ready, willing and able to try a case and which are not. If your lawyer is not respected by the other side, or is not really ready to try the case to a jury, he or she is highly unlikely to get the best possible settlement offer from the defense. At Berman and Simmons, we prepare our cases to be tried and our opponents know that.

Here is a county by county description of some of the product liability cases we have worked on:

Androscoggin County

-Ladder failure- fall, multiple fractures

-Metal bold failure- eye injury

Aroostock County

-Hay baling machinery- death

-Potato harvesting machinery- arm entanglement

Cumberland County

-Carbon monoxide leak- brain injury

-Farm machinery- hand crush injury

-Ladder failure- fall, skul fracture, brain injury

Franklin County

-Medication defect- failure to warn, birth defect

Knox County

-Soda bottle explosion- loss of an eye

-Bucket loader- transmission control crush injury leading to death

Oxford County

-Rifle defect- drop fire, bullet wound

-Safety equipment failure- severe laceration from chain saw

-Ski binding failure- paralysis

Penobscot County

-Hydraulic cylinder explosion- burns

Sagadahoc County

-Gas explosion- burns

Somerset County

-Gas explosion- burns leading to death

York County

-Saw mill saw blade fragmentation failure- severe lacerations

State of New Hampshire

-Safety equipment failure- defective design of insulated work platform for electrical worker, electrocution, burns leading to amputation and death.

Gas powered refrigerators have been in use since at least the 1930s. They are particularly suited for use in places where the electrical grid does not run, such as fishing, hunting and logging camps.  Partly because they are used in remote locations and partly because of the defective design of flues, vents and burners in certain models, gas refrigerators should be considered to be extremely dangerous.

Gas refrigerators can be fueled by natural gas (which is usually mostly methane mixed with other combustible gases), or LP (liquified petroleum) gas, the most common of which is propane. The danger in all of these fuels lies in incomplete combustion, which occurs when either the flow of intake air or the venting of exhaust becomes disrupted. Either problem, or a combination of both, can result in the discharge of carbon monoxide, an odorless, colorless and deadly poison.

Sellers of gas refrigerators and government regulators have known for many years that gas refrigerators are prone to vent problems and thus very dangerous. Set out below is a report from the Consumer Product Safety Commission describing particular problems with certain Servel models which have caused many brain injuries and deaths through release of carbon monoxide.

The Servel models described below is just one of many dangerous gas refrigerators.  Several older models from other makers present the same risks to health and safety.  For instance, there have been a number of reported injuries and deaths from carbon monoxide involving the Consul models manufactured by Whirlpool S.A.

Gas refrigerators are most common in remote camps because compressed gas is the easiest fuel to transport into the woods. The remote setting of these camps contributes to the danger of the refrigerators in the sense that they are often used only seasonally. People do not think to service appliances that are used only intermittently, it is expensive and inconvenient to get service personnel in, and long periods of disuse in an environment which goes from extremely hot to extremely cold, and which is often damp, leads to rust, corrosion, dust, cobwebs, and insect nesting. All of these contaminants disrupt air flow and damage burner and vent components, leading to carbon monoxide production.

If you have a gas refrigerator,  you should consider whether it is safe to continue to use it. Service may help eliminate or minimize the risk of serious injury, but that might not be enough.

If you or someone you love has been injured by a gas refrigerator or other gas appliance, you should call Berman and Simmons or another law firm with experience with such cases. We have  handled asphyxiation cases associated with many home appliances in addition to refrigerators, including cook stoves, furnaces and space heaters.

We have also represented many families injured bya different risk associated with LP, propane and natural gas:  explosions.  If a pilot light or other component fails,  or if the seller/delivery person fails to properly test for leaks in the gas distribution system, gas can leak into the living space and lead to catastrophic burns and death.  Visit our website and other entries in this blog for  further information and commentary.

John Sedgewick, Esq.

Berman and Simmons

1 800 244 3576

www.bermansimmons.com

U.S. Consumer Product Safety Commission

1. CPSC, Warns That Old Servel Gas Refrigerators Still In Use Can Be Deadly

WASHINGTON, D.C. – Government safety experts continue to warn consumers to stop using Servel gas refrigerators manufactured between 1933 and 1957 due to the risk of carbon monoxide leakage in deadly quantities.

The U.S. Consumer Product Safety Commission (CPSC) reports there have been at least 39 incidents in the U.S. involving these old Servel gas refrigerators, causing 22 carbon monoxide-related deaths and 55 injuries nationwide. There also have been incidents reported in Ontario, Canada, causing 60 deaths.

Because historical sales and distribution records of these early Servel models are unavailable, it is not possible to determine who still owns and uses these refrigerators. The Servels continue to be used in hunting cabins, vacation cottages and remote areas of the nation where there is no electricity, or where gas is the preferred energy source.

Over a period of time, especially if the refrigerator has not been used recently, the gas burner can be fouled by dust, dirt, rust or other obstructions. Any gas refrigerator with an improperly adjusted or partially plugged burner can produce substantial amounts of carbon monoxide.

Consumers can call the Servel Corrective Action Committee (SCAC) toll free at (800) 782-7431 anytime to receive a rebate package that includes instructions for disposing of their Servel gas refrigerator. Consumers who properly dispose of their old Servels will receive a $100 rebate plus reimbursement for reasonable disposal costs.

Since this recall program was launched in 1990, more than 22,000 refrigerators have been destroyed. On average, 100 new requests for rebates are mailed to SCAC monthly, demonstrating that there are still many more in use.

Consumers who insist on keeping their old Servel refrigerators should move them to an outdoor shelter, shed or garage not connected to the house or cottage. CPSC urges owners to secure or restrict access to refrigerators kept outside and, when discarding any refrigerator, to remove its door. This will prevent children from playing in the refrigerator and possibly getting trapped and suffocating inside.

CPSC advises that all gas refrigerators be serviced regularly by licensed technicians in order to assure their safe operation. They also should be inspected after they are moved and before they are turned on after a seasonal shutdown. Special attention should be paid to blockages in burners and flues.

No longer in business, Servel manufactured gas refrigerators between 1933 and 1957. The Servel refrigerators in question are no longer being produced and are in no way associated with the Dometic Corp., the current manufacturer of Servel brand name products.

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The U.S. Consumer Product Safety Commission is charged with protecting the public from unreasonable risks of serious injury or death from thousands of types of consumer products under the agency’s jurisdiction. The CPSC is committed to protecting consumers and families from products that pose a fire, electrical, chemical, or mechanical hazard. The CPSC’s work to ensure the safety of consumer products – such as toys, cribs, power tools, cigarette lighters, and household chemicals – contributed significantly to the decline in the rate of deaths and injuries associated with consumer products over the past 30 years.

To report a dangerous product or a product-related injury, call CPSC’s Hotline at (800) 638-2772 or CPSC’s teletypewriter at (301) 595-7054. To join a CPSC e-mail subscription list, please go to https://www.cpsc.gov/cpsclist.aspx. Consumers can obtain recall and general safety information by logging on to CPSC’s Web site at www.cpsc.gov.

A handle is something that we expect to be able to grab and move to achieve a specific purpose. We expect that, gripping a handle, we can open a door, lift a chainsaw, hammer a nail.  When we say we have “got a handle” on a problem, we mean that it is under control. Lawyers who are asked to handle cases are expected to direct and guide them to a proper conclusion. In all contexts, we think of a handle as something secure, reliable and useful.

When handles fail, they may cause serious injury. Discussed below are three examples of handles that failed, surprising the people who relied on them. The handles were not secure, reliable, or useful, and became the subject of product liability cases. Each case represents a different failure mode. Considered together, the cases provide insight into analyzing other possible handle defect cases.

The Gardener’s Cart

An amateur gardener bought an unassembled cart, in a cardboard box, from a local retailer. The cart had two bicycle-type wheels with a plastic tub between, and was held together by a tubular metal frame. The handle was an extension of the frame, with two longer tubes, one on each side, coming diagonally up toward the user and a cross piece, also tubular, that slipped into and connected the two longer tubes.

The gardener was not mechanically inclined, but the assembly instructions were simple and he was able to get the cart built. He took it out to the garden and used it for hauling weeds, sod, fertilizer, mulch, etc.

As long as he was pushing the cart, it worked fine. One day he was pulling it, trying to get a small load of stones up over a threshold into his barn, when the handle suddenly came off in his hand. The gardener fell back, banged his head, and suffering a serious head injury.

The family gathered the parts of the cart and spoke to a lawyer. They bought an exemplar cart, also in a box with instructions, from the same retailer. The exemplar was identical to the defective cart. The instructions confirmed that the failed cart had been assembled as directed by the designer.

The explanation for the accident, and the defect, quickly became apparent.  The design of the handle called for the cross piece to slip into the two side tubes, but did not call for a fastener to hold it in place. As noted above, as long as the cart was being pushed, the cross piece and the side tubes were being pushed together. With light pulling backwards, friction prevented the cross piece from being pulled apart from the side pieces. With heavy pulling, however, the friction fit between the pieces was not powerful enough to hold the pieces together. The cross piece came off in the gardener’s hand because the designer failed to provide a fastener, such as a ten cent bolt, to hold it together.

If you or someone you know has been injured by a product that was designed without proper fasteners, or with defective nuts or bolts, speak to an attorney with experience in proving such cases.

During a downhill ski run, the legs encounter high levels of bending and twisting forces as the skis hit ruts, bumps, ice and other features of the terrain. Because those forces are most often encountered as brief spikes of force, it is not desirable to have the skier released from the bindings every time the level of force gets in the dangerous zone. Properly designed alpine ski bindings are elastic, or capable of absorbing the brief spikes of force, without releasing.  The elasticity in the binding protects the skier from unnecessary, and potentially disastrous, early releases of the bindings.

Exploring how elasticity is a factor in alpine ski binding design and performance is not easy because there is very little written about it, and because few people outside of the ski binding manufacturers have studied it.

The very concept of elasticity in ski bindings is unknown to most skiers. To understand it, you must realize that the connection between ski and ski boot is constantly subjected to high forces during skiing. It is, after all, only through that connection that the skier is able to control his speed and direction. Also, one must realize that it is not force alone that breaks bones, but force exerted over time. Leg bones can withstand very high force levels without breaking as long as they are exposed to those forces for only a very brief period of time. This is true because of the capacity of the bones to bend. If the bending force is imposed and removed quickly, the bone absorbs the force by bending and straightens out again, and the skier continues down the mountain.

Because his bones can absorb spikes of force, a skier can ski through bumps, ruts, caught tips, and other events which cause forces on the leg to spike briefly. If the binding is not able to tolerate these spiking forces, it will release even though there is no risk of breaking a bone.Even in normal skiing forces spike so often that frequent releases will occur in non-elastic bindings, spoiling the fun of skiing but also, and more importantly causing the risk of major neck and head injury from inadvertent release.

Thus, to be safe and useful, an alpine ski binding must be able to absorb brief spikes in force without releasing. If it can do that, it is said to be elastic.