TransformerRobot Posted December 31, 2011 Share Posted December 31, 2011 From what I remember the fastest commercial motorcycle we have is the MTT Turbine Superbike Y2K, at 365 km/h. I can imagine that at that top speed, if the rider fell off, the rider would be in a lot of pain and probably some broken bones. Yet there are some people who would like bikes to be faster for more excitement, even though it would be more dangerous. So I'm asking for your opinions on this matter: With regards to an open cockpit vehicle moving at high speeds, and the possibility of the rider wiping out, how fast is too fast? Link to comment Share on other sites More sharing options...
Phi for All Posted December 31, 2011 Share Posted December 31, 2011 Terrain is the key factor here. A motorcycle moving at 365 kph+ doesn't turn well, or retain control over even the slightest hilltop. It doesn't react well to anything but smooth, obstacle-free straightaway at those speeds. I can't imagine that would be a very long-lived thrill for those who desire more lethal excitement. Link to comment Share on other sites More sharing options...
TransformerRobot Posted December 31, 2011 Author Share Posted December 31, 2011 Then what about the levitated bikes I hypothesized about in another thread? Same idea as a motorcycle, just without wheels and magnetically levitated. Such an idea should keep the rider somewhat safer at high speeds, right? (Sorry, I forgot about that in my previous post). Usually the roads for my bikes are either metallic, or the superconductor system(s) are buried beneath plains of grass, shallow water, etc. So in any of those scenarios how fast would be too fast? In case you forgot I'm trying to make the bikes very fast and exciting, without killing the riders. Link to comment Share on other sites More sharing options...
DrRocket Posted January 1, 2012 Share Posted January 1, 2012 Then what about the levitated bikes I hypothesized about in another thread? Same idea as a motorcycle, just without wheels and magnetically levitated. Such an idea should keep the rider somewhat safer at high speeds, right? (Sorry, I forgot about that in my previous post). Usually the roads for my bikes are either metallic, or the superconductor system(s) are buried beneath plains of grass, shallow water, etc. So in any of those scenarios how fast would be too fast? In case you forgot I'm trying to make the bikes very fast and exciting, without killing the riders. Since you are talking pure fantasy no speed is too fast. The only way to kill your riders is with a pen. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 1, 2012 Author Share Posted January 1, 2012 (edited) Yes, it is fantasy, but I'm applying whatever real world physics I can to it. I've attached an image of my ideal machine to give you an idea. So far I have the rider positioned behind a windshield. The part at the end of the bike is the propulsion/retrorockets. Edited January 1, 2012 by TransformerRobot Link to comment Share on other sites More sharing options...
Schrödinger's hat Posted January 1, 2012 Share Posted January 1, 2012 The speed of sound would be an obvious hard to overcome limit. I'm not sure how harmful the shockwave would be if you were that exposed, but it would not be pleasant. That still leaves us with the range 400-1000km/h. A quick look at motorcycle speed records reveals many in this range. Although further investigation indicates that most of the vehicles travelling faster than about 400km/h are fully enclosed. This indicates two things: Going fast without a fully streamlined vehicle is hard Those people who want to go fast prefer the extra speed (or convenience) an enclosed vehicle provides. I would thus conjecture that the limits on drag and stability imposed by having an open canopy like the one you show are important at lower speed than the limits wheels impose. Further, if someone was going to go to the expense of doing this on a specialised track or arena, they would do it on the existing salt flats which can be found in many countries rather than building a dedicated (and very large and expensive) track for superconductors. They might build these specialised tracks for higher speeds than wheels allow, but reaching such speeds without good streamlining (including a closed cock-pit seems unlikely. Also at these speeds, it tends to be staying on the ground that is difficult (especially around or above the sound barrier). If you had a power/thrust source capable of keeping you at supersonic speeds for prolonged periods (this is difficult with wheels) then you would probably just fly. Maglev seems more feasable in this case, but the main attraction of magnetic levitation is that it is extremely energy efficient. This is completely at odds with the idea of a small, high frontal surface area to volume/weight vehicle with a single occupant, you would be using so much energy overcoming drag that the extra required to keep you fully airborne would not really factor into it. So again, you'd be more inclined to fly. Flying would also be safer. Thrill-wise it may not be quite as desirable, but you might depict pilots getting thrills by flying at lower and lower altitudes. One final concept that could be used is some kind of MHD based drag reduction. In this case your vehicle would also contain extremely powerful (far more compact and more powerful than we have today or know how we might build) magnets. It would also have highly sophisticated control for the field generated. As such, some kind of magnetic levitation would be the obvious choice. This would require smaller expense for the track; permanent magnets could be used. I don't really see such a vehicle being open-topped. It would necessarily be surrounded in plasma, and electric and magnetic fields powerful enough to be dangerous. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 1, 2012 Author Share Posted January 1, 2012 That's all very good and helpful information, thank you, but if I made the vehicle fully enclosed nobody would no it's based on a feet forward motorcycle. When people think of hoverBIKES they think of a hovercraft with properties of a motorcycle (Single occupant, open cockpit and handlebars). If they were fully enclosed vehicles, wouldn't I have to call them something else like Pods or Capsules? Link to comment Share on other sites More sharing options...
Phi for All Posted January 1, 2012 Share Posted January 1, 2012 Most of your problems stem from the fact that the bike needs something to push against for traction. Perhaps you can "invent" some kind of local field that the bike creates under it's tires (obviating the need for costly and limiting buried superconductor systems) so it can maneuver any way it likes and the field always banks, inclines or declines with it, based on the center of gravity of the bike and rider. You may not need the enclosure then either, if the field keeps the rider pressed to the bike so he doesn't fly off (since an open motorcycle design looks cooler and would probably please thrillseekers more). Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 1, 2012 Author Share Posted January 1, 2012 Thanks, but what you just said sounds more fictional, and I'm trying to use real physics to explain it. I'm sure everybody else out there is tired of science fiction technology that can't be achieved in real life; That's what they saw in The Flintstones over The Jetsons. Link to comment Share on other sites More sharing options...
Schrödinger's hat Posted January 2, 2012 Share Posted January 2, 2012 As you're the author, you're going to have to draw the line between science and fiction, along with practicality vs whatever is important to your story. The idea of an MHD drive would simultaneously explain the ability to hover with a low cost track, the ability to overcome drag to an extent and the ability to move fast without becoming unstable. As I said it would probably be impracticle/dangerous to have an open canopy in this case, but this could be handwaved away easily enough (someone willing to move close to mach 1 at low altitude may not baulk at having to be careful where they put their hands around a possibly lethal electric field). If this was the case, the pilot wouldn't even need a windscreen/complete windscreen (although it would probably be helpful), as the same mechanism which guides the air around the craft could be used to deflect the air flow. The only problem I see with this is that an MHD drive this powerful would probably allow you to fly, so again it comes back to justifying why the pilot isn't at higher altitude. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 2, 2012 Author Share Posted January 2, 2012 You mean there's the possibility of using a secondary magnetic field on the bike to move air around it? Link to comment Share on other sites More sharing options...
Schrödinger's hat Posted January 2, 2012 Share Posted January 2, 2012 Most of the magnetic field would be produced by the bike. You could use relatively weak permanent magnets (or possibly something involving diamagnetism, although this is mere conjecture and I'd have to investigate it) on the ground to keep it airborne. Read up about magnetohydrodynamic drives. They're based on fairly sound physical principles. The main reasons we don't have them are: Incomplete understanding/ability to model turbulence and plasma physics. Lack of power sources Lack of powerful enough magnets. It's fairly reasonable to ignore these limitations in scifi. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 2, 2012 Author Share Posted January 2, 2012 In other words say that the riders avoid being thrown off the bikes at such high speeds because of highly developed technology for manipulating magnetic fields, but I don't HAVE to explain how it works or how it was perfected. Link to comment Share on other sites More sharing options...
JustinW Posted January 2, 2012 Share Posted January 2, 2012 For the sake of argument, if you can make the bike levitable with enough energy to support it, I would think the max speed for an open cab, feet forward vehicle would be as fast as you could breathe at. Without a source of oxygen the resistance of the outside air itself would stifle the driver enough to not be able to breathe. Of course a source of oxygen and a windshield could solve this problem. That is to say that they can maintain control at such resistance in the first place. It would seem that the more corrections you make for such problems, the less and less it would look like a bike. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 2, 2012 Author Share Posted January 2, 2012 Then the top speed I can think of so far, without killing the rider, is 365 km/h. How about 450-500 km/h? Yes, I'm keeping in mind the safety differences between a bike and a car. Link to comment Share on other sites More sharing options...
Moontanman Posted January 3, 2012 Share Posted January 3, 2012 (edited) If you fall off a motorcycle at 20mph (32kph) it's likely to hurt you badly, I have been on bikes at over 180mph (290kph), it was a quite thrill the first couple of times but my tolerance to adrenaline is quite high, mostly due to doing crazy stuff on motorcycles for fun. it's very difficult to go fast on a motorcycle in terms of power applied, the faster you go the harder it becomes to accelerate. Motorcycles are not very aerodynamic, it takes a a lot of hp to go 120mph (193kph), about 100hp (73kw)will do it if the bike is relatively light. to go 150mph (241kph) takes about 180hp, 200mph (330kph) would take a lot more than 200hp (146kw). Chrysler made a motorcycle with a V10 engine, the tomahawk, it was estimated to be able to go 300mph+ (480kph), it had over 500hp (372kw), as far as I know no one ever really tried to see how fast it would go, the bike was considered so dangerous it was delivered to it's owner in a non running state and was considered as work of art and could not be licensed to ride on the highway. Of course a fairing changes these estimates quite a bit but most 200hp motorcycles are still incapable of going more than about 185mph (297kph) or so. One commercial motorcycle was said to be able to break the 200mph (330kph) barrier but Suzuki put a governor on them, so they can't go much past 180mph (290kph) or so, far too many people would buy then and die on the way home. I think officially 180mph (290kph) is the limit and most bikes are now limited by governors to less than 180 mph (290kph) or so. Although many bikes top 200hp easily. http://video.google.com/videoplay?docid=-472004366476459286 Edited January 3, 2012 by Moontanman Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 3, 2012 Author Share Posted January 3, 2012 Thank you all for your input and feedback, but now I think I should ask this: Is more speed really what motorcycle racing needs to be more exciting? First look at footage of this REAL race in Ontario: Now look at this VIRTUAL race on the Nintendo GameCube: http://www.youtube.com/watch?v=bwbTEOETf7g After watching them both, which was more exciting? Link to comment Share on other sites More sharing options...
CaptainPanic Posted January 3, 2012 Share Posted January 3, 2012 Then the top speed I can think of so far, without killing the rider, is 365 km/h. How about 450-500 km/h? Yes, I'm keeping in mind the safety differences between a bike and a car. What do you mean "top speed without killing the rider"? On a perfectly flat surface (or when levitating high enough above the ground, i.e. flying low) there is no theoretical maximum if the "biker" is enclosed. You can just invent a low flying rocket or jet. Here's a movie of a F-14 fighter going supersonic at low altitude. It depends on you (the author) how much real-life you allow into the story, and how practical this should be. If the biker can fall off somehow, you kill him at anything above 150 km/h I guess. Bikers survive such speeds only at racetracks with large areas of completely flat gravel and grass, because they have a soft landing and plenty of space to roll over and slowly reduce their kinetic energy. And even then they risk injuries. In the normal world (for example on highways), there are many more obstacles on the side of the roads: trees, signposts, bridges, other vehicles. Hit any of those at anything above 80 km/h, and you're in very serious trouble. Hell, probably 30 km/h is dangerous already if you hit a tree face first. In addition, staying on the bike is not so much a problem with wind force. A modest windshield can protect you. It's all about bumps in the road. With higher and higher speeds, a tiny bump can launch you and your bike into the air. And that would be the end. And in the real world, on real highways, I don't think anyone can reach that 365 km/h. Because real highways have corners, bumps, traffic, etc. Here's a of what it looks like to go 417 km/h in a car. You need a very (very) long straight road, which is very flat, otherwise you will fly off. Link to comment Share on other sites More sharing options...
dimreepr Posted January 3, 2012 Share Posted January 3, 2012 If you remove the wheels you will also remove the stability they provide. Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 3, 2012 Author Share Posted January 3, 2012 What about maglev trains? With a maglev system like previously discussed I could use the same breaking method as the trains. Remember the example I showed you with how the bikes' rear ends have both thrusters (for going forwards) and retros (to slow down or stop). Link to comment Share on other sites More sharing options...
CaptainPanic Posted January 3, 2012 Share Posted January 3, 2012 I think the question of the thread is not clear anymore. Are we discussing a real-life maximum speed for surviving a fall off a moving motorcycle, as stated in the OP? Answer: not so fast. Most people will have serious injuries at regular highway speeds. There is a reason that driving a motorbike is 35 times more often fatal than a car. (wikipedia) Per vehicle mile traveled, motorcyclists' risk of a fatal crash is 35 times greater than a passenger car. Or are we discussing a sci-fi (but real physics) top speed for a (ground?) vehicle? If so, the question is not clear. What is important? Should it just be cool? Should it be as fast as possible? Should it be able to move everywhere? Should it be practical? Should it corner, or just go like hell on the straight? Is the road perfectly smooth? And why can it not be an airplane (which can land vertically)? What's the reason to stick to a surface? I mean, yes, you can build a maglev motor for 1 person sitting in a half-open cabine, with multiple thrusters... If designed with future materials and methods, the laws of physics don't stop you. So, we can only discuss the practical side of this, which brings us to the question: "WHY?" Because a single-seat electric chair with rockets attached to it doesn't sound like a practical means of transportation to me Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 3, 2012 Author Share Posted January 3, 2012 I want it to be cool, AND possible. Just look at what these people built: http://www.youtube.com/watch?v=lezLpOmdZUw Look at it and tell me that's not the Spider Mech from Wild Wild West. The laws of physics today are different from what we'll have in the future, assuming the laws of physics will change in the future. Skipping the laws of physics is for Transformers and My Little Pony, not for a serious story about high speed racing. A friend told me yesterday that Pod Racing was so exciting because of how many drivers got hurt in all the action. If I don't make racing faster in my story it may not be as exciting, and would be dismissed as just like today's Superbike competitions, and nothing more. Most of all, by applying real physics to the story people would actually think I'm smart, and not just some ordinary reporter using his imagination to create an ideal world. Specifically this, without the annoying tractor beams: Link to comment Share on other sites More sharing options...
Moontanman Posted January 3, 2012 Share Posted January 3, 2012 (edited) Thank you all for your input and feedback, but now I think I should ask this: Is more speed really what motorcycle racing needs to be more exciting? First look at footage of this REAL race in Ontario: Now look at this VIRTUAL race on the Nintendo GameCube: http://www.youtube.com/watch?v=bwbTEOETf7g After watching them both, which was more exciting? I've raced, trust me it is far more exciting that playing a video game.... I get the impression not a lot of experienced bikers here... riding motorcycles is a skill set not everyone can master, they are dangerous but also safer, I sounds like a contradiction but it's very true. If you know how to take advantage of the advantages a motorcycle has it can be safe and fun... till some a-hole pulls out in front of you and you t-bone him.... BTW, motorcycle racing is about as fast as it can get with the technology available to the builders, at this point tire wear seems to be the most limiting factor.... The rear tire on a powerful motorcycle looses traction quite easily and spends a lot of time spinning faster than the front tire. If I don't make racing faster in my story it may not be as exciting, and would be dismissed as just like today's Superbike competitions, and nothing more. Superbike racing is dismissed? Not by motorcycle fans, it is far more serious racing than the whole NASCAR go fast turn left crap.... Edited January 3, 2012 by Moontanman Link to comment Share on other sites More sharing options...
TransformerRobot Posted January 3, 2012 Author Share Posted January 3, 2012 I've raced, trust me it is far more exciting that playing a video game.... I get the impression not a lot of experienced bikers here... riding motorcycles is a skill set not everyone can master, they are dangerous but also safer, I sounds like a contradiction but it's very true. If you know how to take advantage of the advantages a motorcycle has it can be safe and fun... till some a-hole pulls out in front of you and you t-bone him.... BTW, motorcycle racing is about as fast as it can get with the technology available to the builders, at this point tire wear seems to be the most limiting factor.... The rear tire on a powerful motorcycle looses traction quite easily and spends a lot of time spinning faster than the front tire. Superbike racing is dismissed? Not by motorcycle fans, it is far more serious racing than the whole NASCAR go fast turn left crap.... Did I ever mention I hate NASCAR? No? Well I'm saying it now. I think it's a load of horse crap full of drunken white trash bums, constant left turns, and that it only generates so much revenue because of corporate sponsorship. Might as well change the acronym to say Non Athletic Sport Centered Around Rednecks (I read that one on Urban Dictionary). -1 Link to comment Share on other sites More sharing options...
dimreepr Posted January 3, 2012 Share Posted January 3, 2012 (edited) I want it to be cool, AND possible. Just look at what these people built: http://www.youtube.c...h?v=lezLpOmdZUw Look at it and tell me that's not the Spider Mech from Wild Wild West. The laws of physics today are different from what we'll have in the future, assuming the laws of physics will change in the future. Skipping the laws of physics is for Transformers and My Little Pony, not for a serious story about high speed racing. A friend told me yesterday that Pod Racing was so exciting because of how many drivers got hurt in all the action. If I don't make racing faster in my story it may not be as exciting, and would be dismissed as just like today's Superbike competitions, and nothing more. Most of all, by applying real physics to the story people would actually think I'm smart, and not just some ordinary reporter using his imagination to create an ideal world. Specifically this, without the annoying tractor beams: the basic laws of physics such as pauli's and hiesenburg's principles will always be correct and cannot be otherwise. you can't just ignore what is fundamentally true. Edited January 3, 2012 by dimreepr Link to comment Share on other sites More sharing options...
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