Author Topic: dustbins round 2  (Read 6371 times)

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Offline hawkwind

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dustbins round 2
« on: December 22, 2005, 05:49:27 AM »
Current rules are ultra conservitive  really :wink: stage 2 of my research  uncovered this little gem
http://www.ihpva.org/tools/cwind_stat_stab.doc
it is fairly technical  but excellent , my current research  is looking very promising  but data is very hard to come by, any futher data or information on this subject gladly accepted  :lol:
http://www.dself.dsl.pipex.com/MUSEUM/TRANSPORT/gyrocars/gyrocar.htm#gyro2
the day is drawing closer ,change is on the wind ,the old will fall and the new will rise like a phoenix from the ashes  :wink:
Gary
slower than most

Offline JackD

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In the wind
« Reply #1 on: December 22, 2005, 07:58:06 AM »
The rules of nature are a lot more steady than the wind they describe.
A steady wind anticipates a steady speed through it and that is not the case with a LSR MC.
 Anybody that flies or sails can also tell you that.
 To anticipate still or constant air over the distance of a run must also consider a small change
 becomes a big problem at big speeds.
Everybody on a single plane vehicle and most others have felt the effect of a cross wind and they don't
 like it.
I know somebody that managed the run time well enough that he had a tailwind for both directions of his attempt.
Break traction and you will quickly go to the head of the class from various directions.
"If you are going to bet against the laws of nature, the faster you go will also be the faster you go."
Touche
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline k.h.

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dustbins round 2
« Reply #2 on: December 22, 2005, 02:15:09 PM »
Gary, as a Christmas present to yourself this year, how about an hour's flight instruction with a decent pilot in a tail dragger doing touch and goes in a cross wind.  The practical factor experience will give meaning to the theoretical ideas in other's published reports.

Is there a "prood of concept" you can do before commiting excessive time and money only to be refused access to the race course with a dustbin sit-on bike?  Aero is good.  Dustbin equals aero, no question.  The key to making this all work may be your addition of a gyro.

And refer to yourself as a designer, not an engineer.  The difference between designers and engineers . . . oh, I better not open that can of worms.
In theory, there is no difference between theory and practice.  But in practice, there is.--Jan L. A. Van de Snepscheut

Offline JackD

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Fly ?
« Reply #3 on: December 22, 2005, 03:42:30 PM »
I got a lot of early hours in the 60s when I was in the AF in Vegas. I flew the CAP J-3 they kept with us. I got to fly it often on a Monday to find a lost Jeeper in the Desert. It didn't have any brakes and a wire brush for a tail wheel. The radio ran from a generator and prop that was bolted to the gear.
I only got in trouble once when I landed into the wind and it was too strong for me to turn off so I just sat on the runway until the came to get me. The trouble was with the 3 F-105 guys that couldn't back up or go around me.
It taught me a lot about dust and bins as I sat there.  I am sure it was the state of the art in it's day . The engineering has changed but the laws of nature have not. :wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

bak189

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dustbins round 2
« Reply #4 on: December 24, 2005, 10:47:20 AM »
We have been racing sidecars at Bonneville for over 25 years, using "Dustbin" fairings. We have 3 wheels (a outrigger) to keep us upright, so the danger of being blown down is not a problem.
However, more then once in all those years of racing, we have been "moved over" on the Bonneville course due to cross winds. In addition we also run a 125c.c. solo bike that a couple of years ago had a "full" front fender (Tom Evans BNI/tech let us try it out and report back to him) it was almost not rideable and it felt to me like the front-wheel was loose. we took the fender off and found no problem.
I would certainly not want to run a full "dustbin" at a place like the Bonneville Salt flats. We also have some input on a full tail section, but this is for another time.

Offline JackD

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The truth is.
« Reply #5 on: December 24, 2005, 11:56:34 AM »
He has probably run more than 25 years.  LOL
The 125cc shrouded wheel on the front works just as good as a rudder on the front of a boat or plane. The TF car boys had steerable and non-steerable front ends and got away from the practice.
I want to see rear steer on a bike, I mean a pedal bike. That is the next big answer to the question that nobody asked.
10 years ago the open bike was going 200 now they are going 260. I don't think they have been perfected yet but the radial tire has come into use and they are better than bias for the application. Tires seem to be the next big threshold and reducing the load on them or tires better suited to the application will get to go faster.
When the classes are reduced to a number and consistency between the locations, that will be a big step towards getting them interested in supporting the sport. It really makes it hard for  them to focus when it is so divided. An individual effort might produce a tire product that is suited to them and only available to them. They would be smart to do it on their behalf but that doesn't always translate into something for everybody.
This is a sport of individuals but you are all in the same boat. If they didn't want to try stuff the bikes might as well be rentals and all the same. The safety record of the bike field will go a long ways towards developments that will also make them faster.
You have probably figured I am a little heard headed about that stuff. :wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

rosemeyer

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dustbins round 2
« Reply #6 on: December 24, 2005, 02:34:08 PM »
Gary,
Almost anything can be made to work in the end; it all depends on the time and money you want to spend to research and develop it.
An idea which seem to be the next breakthrough in a particular area can take years to perfect and may lead to the addoption complicated solutions to correct what is a basic flaw. The 'Flying Wing' design in the 50s, for example, was supposed to be the next step in aircraft design. Some said it was highly unstable, other stuck to their guns and researched it at huge expenses until they made it fly, just to prove their point. It was a blind alley: once the boffins made it work, the concept was unpractical and was never addopted.
Combining the dustbin fairing, rear boat tail and gyros on 2-wheel is the same. I am sure that someone with unlimited budget, laboratories, technicians, etc... could make it all work in the end. But to prove what?
Probably it would need a computer to coordinate the functions, complex programmes to make it work, months if not years work of analysis and study to tune it.
Alex Tremulis who benefited of quite a lot of resources when he designed Gyronaut gave up trying to use gyros for a record vehicle. Basically they create static stability at the expense of maneuverability on the move. Gyros work better in 3 dimensions than 2. Steering a bike, siton or streamliner is still a 'seat of the pan' feeling, and that would be taken away by the interference of a gyro. Unless we want to give up the rider's input in record breaking and reduce him/her to a mere passenger during runs where the trajectory and stability functions are taken over by computers analyzing all the different parameters during a run (wind speed, lean angle, pitch, etc...) and controlling the steering and the gyros, we better keep to what is the current practice.

Offline Sumner

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Re: dustbins round 2
« Reply #7 on: December 24, 2005, 03:58:36 PM »
Quote from: hawkwind
Current rules are ultra conservitive  really :wink: stage 2 of my research  uncovered this little gem
http://www.ihpva.org/tools/cwind_stat_stab.doc
it is fairly technical  but excellent , my current research  is looking very promising  but data is very hard to come by, any futher data or information on this subject gladly accepted  :lol:
http://www.dself.dsl.pipex.com/MUSEUM/TRANSPORT/gyrocars/gyrocar.htm#gyro2
the day is drawing closer ,change is on the wind ,the old will fall and the new will rise like a phoenix from the ashes  :wink:
Gary


I'm not trying to get on you about this  :) , but I'm wondering if they did allow dustbins would you then want them to run in an existing class or would you want a new class developed?

c ya, Sum

Offline hawkwind

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dustbins round 2
« Reply #8 on: December 25, 2005, 01:41:03 AM »
Thankyou all for your input , it is very appreciated even if it won't stop me from chasing my dream or agenda , it will temper my raw enthusiasmand allow me to check out both sides of the coin ,so to speak  :wink:
Gary
slower than most

Offline JackD

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Perfection ?
« Reply #9 on: December 25, 2005, 04:37:39 AM »
The streamliner class allows a dustbin and a boat tail now. The wrinkle is that it also requires the safety measures that have proven very effective over the years.
Make a streamliner go faster, we are ready. :wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline k.h.

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dustbins round 2
« Reply #10 on: December 25, 2005, 02:40:22 PM »
Gary--  Don't give up, find a way to make the rules work for you.  Perhaps there is a way to "game the system."  Here's another cut and paste from Tony Foale's article on Aerodynamics with attentnion to centre hub steering:

  "In 1986 I converted a Gold Wing from telescopic forks to one of my "hub centre" front ends, for its owner, Wayne Boys. After he had had it for a while we discussed the various effects that he noticed in normal riding, many observations were as I had expected but I was a bit surprised when he pointed out that it was far more stable in gusty side winds. At first I thought that this was probably just due to the greater lateral stiffness of the new suspension, which is generally more stable anyway. But a bit more thought as to the differences between the two setups, shed a bit of light on why they should behave so differently under these conditions. There seemed to be three main differences, in addition to the stiffness already mentioned ;----- 1. 16" wheel instead of 19", 2. Less trail, 3. A 17 rake angle which needed zero offset between the steering axis and the wheel centre-line to achieve the desired trail. It can be argued that all three of these changes work toward improving the performance in gusts.

Smaller wheel;----- The precessional forces will be reduced in line with the reduction in weight close to the wheel/tyre circumference. This will reduce the coupling between yaw and roll movements.
Less trail;----- The component of the wind side force, acting at the front of the machine is passed to the road surface through the tyre via the steering axis, but the steering axis is in front of the tyre contact patch by the amount of the trail, and hence the sideways force on the bike will tend to steer the wheel with the wind. Exactly the situation that we might wish to avoid.
Zero offset;----- With normal steering geometry with about 1-2" of offset, the bulk of the wheel side area is forward of the steering axis, this combined with the effect of today's large tyres and discs means that a considerable steering force can be generated by the action of a side wind on the wheel. But with the zero offset geometry used on the hub-centre arrangement, this wind force is balanced about the steering axis and no turning effect is produced.

An interesting feature that I noticed when riding my QL. to last year's Milan show, was the effect that tyre pressures had. The QL. has a streamlined body with a fairly large side area, and so the magnitude of the side wind forces may be expected to be high. Now, while the machine appeared to be aerodynamically directionally stable, it would squirm about alarming if the tyre pressures were allowed to drop. This happened due to what was later discovered to be a slow leak at the valve on the front wheel. It appears that the reduced lateral stiffness of the tyres when under inflated, allowed the machine to move about excessively under the action of the high lateral wind force. "

May the New Year be kind to dustbins . . .
In theory, there is no difference between theory and practice.  But in practice, there is.--Jan L. A. Van de Snepscheut

Offline JackD

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Headed for a solution ?
« Reply #11 on: December 25, 2005, 04:05:08 PM »
A solution that seems to make an improvement at 50 mph needs to work well enough at 350 to get by.
Making something that is bad for a reason better will only raise the bar but still will be bad for the same reasons.
That is what inovation is all about and safety too.
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline k.h.

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dustbins round 2
« Reply #12 on: December 25, 2005, 07:33:02 PM »
Ecomobile: fish or fowl, ultimate dustbin/boat tail or unsafe streamliner, legal or illegal in LSR?  They have a race series in Europe.

http://membres.lycos.fr/pmegard/c03_e.htm  Please note the video clip at the bottom of the photographs page showing a spin-out, then raising the rig and continuing on.  Also photos show the machine in an 80 kph cross wind on the Mercedes track.

http://www.peraves.ch/monoe.htm  The mono passenger turbo version clips along at 202 mph out of the box, and with 6 point FIA harness (Ooops, is it a car or a bike???).  Now, with a turbo Hayabusa motor . . . .

http://www.monotracer.ch/  Safe as in a mother's arms . . .
In theory, there is no difference between theory and practice.  But in practice, there is.--Jan L. A. Van de Snepscheut

bak189

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dustbins round 2
« Reply #13 on: December 26, 2005, 07:02:53 PM »
In August of 1973 at the Bonneville Salt Flats a record of 136.50mph. was set by the then development engineer for Can-Am motorcycles Bob Barker on a 125c.c. bike. todate this record still stands.  This outstanding speed with less then 30hp. was mainly due to the fact that the partial streamlining had been developed and tested in the wind tunnel, thanks to the National Research Council of Canada.
My point is there is still room for improvement using partial streamlining. An interesting sideline to the above is that Airtech (Kent) has the mold and the fairings for sale to make your small bike go faster......and this fairing has been developed in the wind tunnel.

Offline JackD

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Yup
« Reply #14 on: December 26, 2005, 08:01:51 PM »
The study he mentions was not only the most work done in the tunnel for Bonneville but demonstrated the problems beyond the limits of the rules.
Only the direction and speed of the wind changes and does all the time.
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"