You'd want to match weight distribution so clusters of Li cells around the engine compartment and fuel tank might work well.

I've always thought this would be a cool business to have. Retrofitting cars with more self-driving features would also be awesome.

It doesn't even look like these guy's are using advanced batteries. Small LIPO batteries distributed around the open areas of the car would make weight distribution better and probably provide a much higher total range.

Maybe they are keeping it simple for cost reasons.

Not too popular in the U.S., but its an Olympic event. Each shot is loaded individually, and people customize them heavily for things like weight distribution. Here is more info:
https://en.wikipedia.org/wiki/10_meter_air_pistol

Very impressive considering differences in centre of gravity and weight distribution.

Weight distribution is just as important too. the beetle has the engine right at the back sot he weight is over the driven wheels. Very little weight up front and the body is relatively tall. That means from the start the rear wheels grip and bite hard, then any weight shift as the car accelerates and the front lifts puts more weight to the rear axle meaning even more grip. Beetles win drag races in the first 20m or so. As you can see in this video the difference in speed in the first second or two is massive. Stop the video at 39 seconds and you'll see in that first launch the beetle has gone twice as far as the mustang. That speed difference that early on is very hard to catch up.

I think that at best this would be applicable only to the very lightest of electric vehicles (something in the "motorcycle" weight class, even half a ton is probably too heavy), and I have my doubts about even those, even when completely disregarding the sideways forces.

With a system like this you do not want more than a few cm (about an inch, at a guess) of suspension travel from when the car is lifted in air to the car at rest (= 1G vertical load), just from the weight of the car compressing the springs. If you have more the springs (which the loops naturally are) have to compress a lot with each revolution, which strains them, heats them, isn't good for rolling resistance, etc.

If we assume a 1000 kg car with a 50/50 weight distribution, to get about 2 cm of suspension travel the spring stiffness would be about comparable to a high level GT racing car. Comparing to high level sports cars, the street going Porsche 911 GT3 RS car, which is regarded as a pretty stiff, racy and track oriented vehicle has something in the region of three times that much travel, a normal commuter car can have way over 10 cm due to soft, comfort oriented springs.

So you can't spring a proper car with just these because it'd require it to be too stiff (also I can foresee shock absorption issues). Another problem is the 360 degree springy nature of it. You really don't want car tyres to move much aside from up and down. These have the problem that when you brake, the forces will try to push the axle forwards in relation to the wheel (i.e. the wheel moves backwards while braking), and the reverse when accelerating. You'd be (possibly) drastically changing the wheelbase of the car during acceleration and braking, which could have catastrophic results for handling in extreme situations. Many if not most cars these days are capable of braking at over 1 G, as long as they have decent tyres, so the front-back movement could be bigger than the up-down movement.

So yeah, doesn't really sound like a workable solution as the ONLY spring system on a car. Having some springiness in the tyres (either in the wheel itself of just having larger profile tyres, like we used to back in the day) can be helpful for comfort and even handling in some cases, but springing the car only via the wheels isn't a good idea, you really want to be able to control the wheels better than that.

You don't see his weight distribution change until about 30 feet before the crash (this is when he started braking). The guy was speeding and not paying attention. Good thing he wore a baseball hat, a short sleeved shirt, jeans, and sandals for protection .... People like this don't last long on motorcycles for pretty clear reasons.

>> ^joedirt:

This stupid video isn't even to scale. Carl Lewis would have been 7 feet from the finish line. The stupid video needs to exaggerate an lie about how far people are from the finish line... Two strides or one body length away, not like 20 feet back.
Why make a "science" like video then lie in it.


As they said in the video themselves this is a field of runners separated by 3 seconds of time. Which will not be that much distance when you boil down the facts that the fastest runner will possibly get near or at 27 mph (something Usian Bolt stuck up there) and less. The slowest runners I imagine will ATLEAST be above 20 mph which really does make this field closer and closer together. They would all be running somewhere between 10 m/s to 10.4 m/s in 12.6 s (the times they ran a VERY long time ago) or up to and past 9.6 s in the modern era.

If you weren't that great of a runner, very quickly, with these type of numbers however, you would find yourself very far behind--it must be almost shocking to see someone gain a 3-5 meter lead on you if you slip up, particularly in the longer length Olympic sprints. It's a great infographic doing everything right, in fact I think they could literally take this concept and bump it up to a 30-60 minute show about the history of Olympic running; I'd throw it on the Discovery or Science Channels. Just look at the numbers I pulled up in a very short amount of time to give some comparisons, there are FAR more things to look at and open up this conversation much, much further... More things to look at could be anything taking in ANY possible connection to a sprinter's performance which may include a few things some people would never even think of, some examples: average foot-span covered each sprinting step and how that has changed with time (longer-shorter, side strides or are they all in line), the possibility of body weight distribution being re-mapped on the body from training, workouts, and diet, over time and has this been a possible endemic change in society (have we become more top heavy, bottom heavy, or averaged out--how does it compare with analysis we can try to make about our Olympic forefathers--with societal changes any of the things I've listed have the possibility of starting there first, moving outward; a true evolutionary or genetic change that might be observed...), shoes and their timeline with features, surfaces used by the athletes through time, how training was done throughout history, our personal livelihood with things like vitamins, a balanced and INFORMED diet allows you to get more out of your muscles then you normally would EVER get, and there is SO much more they could explore!

I would love to see a very well done show about this and if they cover the subject substantially and extensively enough, I wouldn't mind it being a short one year series. As long as they stay true to the overall presentation found in this infotainment/info-graphic and the information displayed here should be, somewhat, natural to us and keep us at ease in which all this material/information is able to be displayed in this show and always making that information available for us to consume and compare just as easily as here. So to me having a large presence online hand-in-hand With a show would be important, of course providing more info-graphics like this for us. One can hope that they'd read our comments and realize, just from a small clip, they have something bigger here--if they want it...

I wasn't quite sure why they "pulled" out the field so far as well, but all I can think is that they were trying to put a exclamation mark on the overall acceleration of the genesis of runners into the modern day.

You can bet they wrecked a lot of good chassis doing these commercials. Launching those cars off of huge pneumatic compressors. It must have been fun getting those cars to drive on their sides too... you could see they had strengthened frames, but the weight distribution must have been a nightmare.