Front steer tire blowout analysis 2
Front Steer Tire Blowout Analysis
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On the video that shows the roll over of the Thor Tuscany motorhome which is pulling a red pickup, the first thing I notice is how this video further perpetuates the MYTH (this video is almost shocking, except that the angle of departure is distorted, which IMO is what makes it almost unbelievable). I used descriptive geometry and arithmetic to discover that the angle of departure (from straight ahead) is only about 18 degrees!! But remember, “We are afraid of those things that we don’t understand”. The myth is that a sudden failure of a front steer tire (blowout) has the capability of pulling the front of a large motorhome to one side and to send it out of control. This myth is also perpetuated by other videos, and also some motorhome drivers/owners who have misinterpreted what really happens whenever a front tire blowout occurs when you’re cruising/driving a big motorhome. Therefore, I will try to explain. BTW, I happen to have knowledge and experience about this subject, but not enough to qualify me as an expert. Yet, the more you know, the better your chances of learning and executing the safe way of handling a blowout. The most important thing to learn is that if this knowledge is already in your mind, you’re not likely to instantly get a brain cramp when you hear the BANG of a blowout and while feeling the serious shaking of the steering wheel. Be aware that a brain cramp puts you out of commission for a few seconds. Beware that in the Tuscany video, it took 4 to 5 seconds for the “healthy” right side tire to reach the grass. This means that if you do NOT go into “brain fade” AND if you only keep doing what you were doing before the blowout, you can just keep on using the steering wheel to stay in your lane. YES, if the ONLY thing you need to do is seamlessly keep using just the steering wheel appropriately, and nothing with your feet, you will have a very good chance of staying in your lane. NOW, the reason this might sound unbelievable is because you have been led to believe that there is a powerful lateral force pulling the front of your motorhome to the side. Neither the blowout itself NOR the flat tire have the capability to do that. Granted, the explanation of what really happens might sound complicated, but IMO by understanding a few important key factors it will mean the difference between loss of control OR not. Therefore I will explain: The blowout allows the air pressure to escape. A flat tire has a much higher rolling RESISTANCE than the inflated tire. How does this affect the steering? Simple: take an old rear- drive beater car to the highway, park and lower the air pressure in one front tire to 10 psi, then get in, and speed up to a constant speed of 40 mph for one or two minutes, get a good feel of the steering wheel, now let go the steering wheel. You will immediately find out the effect of what and how a motorhome will “self steer” when a front tire SUDDENLY fails AND the steering wheel is UN-ATTENDED. So, why does the the driver fail to drive with the steering wheel. It’s simple, he either had a heart attack, or more likely, immediately experienced a brain cramp or a blank out, or brain freeze. In the video it looks like the driver came to his senses AFTER the motorhome went out of control. Most drivers never have the opportunity to learn how NOT to be startled or shocked by something like a front tire blowout. But, some of us are lucky to be professionally trained to handle life and death emergencies . To me, a steer tire blowout experience is similar to a V-1 cut in a high performance twin jet aircraft (in this event the pilot flying MUST instantly and correctly “steer” the aircraft, due to having a flamed out engine on one side,…just as you pass V-1 speed). There’s no time to think, you either perform correctly, or…..disaster. That’s just a small part of the training.
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IMO while cruising on the open highway, if you experience a front tire blowout, if the ONLY ONLY thing you do is to instantly use the steering wheel with authority for the purpose of staying in your lane, you will get a feeling of being in control… (one reason is that you’ll realize you can do it ). I urge you to use all your concentration on steering correctly/appropriately FIRST. The fact is, you have been using the steering wheel for steering since the first time you drove. So, why quit just because of a blowout? Yes, impact torque will be generated on the steering wheel whenever a significant difference in rolling resistance occurs between the two steer tires. It’s nothing new! Just like when one steer tire hits the big puddle of water at high speed. The driver feels it at the steering wheel. It’s just a STEERING ACTION coming back through the steering system. AND, it’s a good thing because this is what tells the driver what to do with the steering wheel. YES, a motorhome CAN SELF STEER right off the road! All it needs is a significant DIFFERENCE in the rolling resistance between the steer tires, PLUS an UN-ATTENDED steering wheel. WHERE is the PROOF that a blowout by itself can “PULL” the front of the MH to the side??? Heck, there’s at least 2 examples, on this forum, of tires blowing out while the MH is standing still. And, the motorhome did NOT move sideways one inch. This is proof enough that too much credit is given to the actual blowout. Analytically, one must look for OTHER cause-and- effect areas of chassis dynamics. For example, MANY drivers will get in their vehicles, and as soon as the engine starts up they start turning the steering wheel, BEFORE the car begins to move. And, when it starts moving it moves in the direction that the steer tires are pointing. So, the vehicle has to generate some momentum for the vehicle to go in the direction the driver chooses. And, the reason the vehicle does not move straight ahead is because a path to the side, of LESS resistance, is offered. AND, if the subject MH is moving forward, it will PUSH, yes PUSH, the front of the motorhome in the direction the front tires are pointing. And, if one steer tire is flat, no matter….the steering system will still work, as long as the rear tires and the inflated steer tire remain on dry pavement (where there is sufficient traction). And, I repeat, if the steering wheel is unattended, it will self steer to the side of the failed tire, by itself. If you do NOT believe it, simply ask the chief steering engineer at a place that has been doing research on the subject of ELIMINATING the onboard human factor. They know exactly what the robot driver has to do immediately upon the first sense of a steer tire blowout… AND, it does NOT include depressing the accelerator. They know that their driver does NOT need more than a few nano-seconds to keep steering and start slowing down. The robot already knows the real-time obstacle map around him. Yes, I know they now have blowout-proof tires, for these driverless delivery vehicles.
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It takes a steering action to duplicate what the subject Tuscany does. The driver would need to quickly turn the steer tires about 15 degrees to the left. Of course, no driver in his right mind would do that at 65 mph. IMO he was NOT in his right mind. For me, it’s the only explanation. Please don’t tell me that a driver would say different. I already know what he’ll say. He’s a smart man. “The force was horribly strong, it took the steering wheel out of my hands.” It’s a good defense. Except that the science of it does NOT agree.
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click
On the video that shows the roll over of the Thor Tuscany motorhome which is pulling a red pickup, the first thing I notice is how this video further perpetuates the MYTH (this video is almost shocking, except that the angle of departure is distorted, which IMO is what makes it almost unbelievable). I used descriptive geometry and arithmetic to discover that the angle of departure (from straight ahead) is only about 18 degrees!! But remember, “We are afraid of those things that we don’t understand”. The myth is that a sudden failure of a front steer tire (blowout) has the capability of pulling the front of a large motorhome to one side and to send it out of control. This myth is also perpetuated by other videos, and also some motorhome drivers/owners who have misinterpreted what really happens whenever a front tire blowout occurs when you’re cruising/driving a big motorhome. Therefore, I will try to explain. BTW, I happen to have knowledge and experience about this subject, but not enough to qualify me as an expert. Yet, the more you know, the better your chances of learning and executing the safe way of handling a blowout. The most important thing to learn is that if this knowledge is already in your mind, you’re not likely to instantly get a brain cramp when you hear the BANG of a blowout and while feeling the serious shaking of the steering wheel. Be aware that a brain cramp puts you out of commission for a few seconds. Beware that in the Tuscany video, it took 4 to 5 seconds for the “healthy” right side tire to reach the grass. This means that if you do NOT go into “brain fade” AND if you only keep doing what you were doing before the blowout, you can just keep on using the steering wheel to stay in your lane. YES, if the ONLY thing you need to do is seamlessly keep using just the steering wheel appropriately, and nothing with your feet, you will have a very good chance of staying in your lane. NOW, the reason this might sound unbelievable is because you have been led to believe that there is a powerful lateral force pulling the front of your motorhome to the side. Neither the blowout itself NOR the flat tire have the capability to do that. Granted, the explanation of what really happens might sound complicated, but IMO by understanding a few important key factors it will mean the difference between loss of control OR not. Therefore I will explain: The blowout allows the air pressure to escape. A flat tire has a much higher rolling RESISTANCE than the inflated tire. How does this affect the steering? Simple: take an old rear- drive beater car to the highway, park and lower the air pressure in one front tire to 10 psi, then get in, and speed up to a constant speed of 40 mph for one or two minutes, get a good feel of the steering wheel, now let go the steering wheel. You will immediately find out the effect of what and how a motorhome will “self steer” when a front tire SUDDENLY fails AND the steering wheel is UN-ATTENDED. So, why does the the driver fail to drive with the steering wheel. It’s simple, he either had a heart attack, or more likely, immediately experienced a brain cramp or a blank out, or brain freeze. In the video it looks like the driver came to his senses AFTER the motorhome went out of control. Most drivers never have the opportunity to learn how NOT to be startled or shocked by something like a front tire blowout. But, some of us are lucky to be professionally trained to handle life and death emergencies . To me, a steer tire blowout experience is similar to a V-1 cut in a high performance twin jet aircraft (in this event the pilot flying MUST instantly and correctly “steer” the aircraft, due to having a flamed out engine on one side,…just as you pass V-1 speed). There’s no time to think, you either perform correctly, or…..disaster. That’s just a small part of the training.
*
IMO while cruising on the open highway, if you experience a front tire blowout, if the ONLY ONLY thing you do is to instantly use the steering wheel with authority for the purpose of staying in your lane, you will get a feeling of being in control… (one reason is that you’ll realize you can do it ). I urge you to use all your concentration on steering correctly/appropriately FIRST. The fact is, you have been using the steering wheel for steering since the first time you drove. So, why quit just because of a blowout? Yes, impact torque will be generated on the steering wheel whenever a significant difference in rolling resistance occurs between the two steer tires. It’s nothing new! Just like when one steer tire hits the big puddle of water at high speed. The driver feels it at the steering wheel. It’s just a STEERING ACTION coming back through the steering system. AND, it’s a good thing because this is what tells the driver what to do with the steering wheel. YES, a motorhome CAN SELF STEER right off the road! All it needs is a significant DIFFERENCE in the rolling resistance between the steer tires, PLUS an UN-ATTENDED steering wheel. WHERE is the PROOF that a blowout by itself can “PULL” the front of the MH to the side??? Heck, there’s at least 2 examples, on this forum, of tires blowing out while the MH is standing still. And, the motorhome did NOT move sideways one inch. This is proof enough that too much credit is given to the actual blowout. Analytically, one must look for OTHER cause-and- effect areas of chassis dynamics. For example, MANY drivers will get in their vehicles, and as soon as the engine starts up they start turning the steering wheel, BEFORE the car begins to move. And, when it starts moving it moves in the direction that the steer tires are pointing. So, the vehicle has to generate some momentum for the vehicle to go in the direction the driver chooses. And, the reason the vehicle does not move straight ahead is because a path to the side, of LESS resistance, is offered. AND, if the subject MH is moving forward, it will PUSH, yes PUSH, the front of the motorhome in the direction the front tires are pointing. And, if one steer tire is flat, no matter….the steering system will still work, as long as the rear tires and the inflated steer tire remain on dry pavement (where there is sufficient traction). And, I repeat, if the steering wheel is unattended, it will self steer to the side of the failed tire, by itself. If you do NOT believe it, simply ask the chief steering engineer at a place that has been doing research on the subject of ELIMINATING the onboard human factor. They know exactly what the robot driver has to do immediately upon the first sense of a steer tire blowout… AND, it does NOT include depressing the accelerator. They know that their driver does NOT need more than a few nano-seconds to keep steering and start slowing down. The robot already knows the real-time obstacle map around him. Yes, I know they now have blowout-proof tires, for these driverless delivery vehicles.
*
It takes a steering action to duplicate what the subject Tuscany does. The driver would need to quickly turn the steer tires about 15 degrees to the left. Of course, no driver in his right mind would do that at 65 mph. IMO he was NOT in his right mind. For me, it’s the only explanation. Please don’t tell me that a driver would say different. I already know what he’ll say. He’s a smart man. “The force was horribly strong, it took the steering wheel out of my hands.” It’s a good defense. Except that the science of it does NOT agree.
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