Landracing Forum
Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials General Chat => Topic started by: PorkPie on February 23, 2007, 10:51:43 AM
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Talked today to Heinz (50th Anniversary NSU Delphin III 200 mph record).
Asked him about the tire for Sam Wheeler and for a general line of highspeed tire for the record breaking.
Unfortunately the answer was not this what we like to hear.
The producer checked everything and at last they was coming to the position to stay away from so tires.
They don't like to risk that they are coming into the responsibility if by some reason something happened.
Heinz has Sam informed.
Sorry folks, for this news :-(
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I am sure there is a reason he has not considered just running a solid aluminum wheel ( no tire) If you profiled ( cambered) and knurled the contact surface this is probably the easiest solution, if not the most cost effective to redesigning the whole front of the motorcycle. Anyone know why this isnt considered an option??
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Sam has already tried the solid front wheel with poor results and salt packing on it.
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Any way I can get in touch with him ( Sam) to discuss the problems, or do you know the specifics of his problems? I am designing a streamliner and had planned to use solid wheels and I would like to learn from his experience if he is willing to share.
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The real problem is the weight and the balance.
The only solution is the way as Craig Breedlove done the wheels/tires for the SoA Sonic Arrow, but nobody can pay this..... :|
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The real problem is the weight and the balance.
The only solution is the way as Craig Breedlove done the wheels/tires for the SoA Sonic Arrow, but nobody can pay this..... :|
The real problem is not weight and balance but lack of contact patch and the required lateral traction needed to keep a MC in hand.
They work on jet cars in the dirt because they displace the surface to get the required side bite.
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Do you think it is possible to counteract the lack of a compliant ( I use the term "compliant" very loosely as the tire has little compliance at 350MPH due to cintrifugal reactions and the high starting pressures) contact patch by profiling the solid wheel in a similar way to a standard motorcycle tire and machining radial blade like protrusions around the wheel, after all there is little lateral force to contend with and no longitudinal force on the front wheel. I am assuming that if the streamliner is balanced correctly in aerodynamic Cp and Cg locations that the only lateral force that needs to be contended is from side loading from crosswinds. Any ideas?
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It won't work any better than an aluminum wheel on a glass table.
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Jack,
Why?
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Jack,
Why?
All of that has been covered extensively on landracing.
In short the altitude record for aluminum front wheels is held by one that was shaped like an Avon Speedmaster.
Tricks you can do at home :
Take a hard disk of any size that is slightly larger than an available rubber band and slide it around a hard surface like a table top.
Then fasten the rubber band to the outside of the disk and try it again.
If the neighbors are not looking you can do the same with your bicycle by starting with the tires off an going round the block.
A DOT approvet helmet should be just fine.
Gather all your conclusions together while on the walk back and let us know how you do. :wink:
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Jack , I believe you , thanks for saving me the expense and trouble of building it only to find out that it diddnt work. At the same time I just cant see how any molecular interlocking can happen at 350MPH with the pressure and centrifugal reaction the tire must be hard as a rock. I am not talking about the rear tire where there is a longitudinal force , only the front where essentially, in my mind, it will never see any lean angle and simply needs to create a small centering force and basically act as a rudder for small corrections in trajectory. I dont have time to read the entire landracing web site, even though I have tried and rarely chime in at that I would still like to have the information. Anybody have a link to the forum Jack is referring to?
Thanks
Nathan
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I don't mean to "SHORT SHEET" you but I do encourage a search on this site to see the various information available.
A further illustration is 2 of the bikes that crashed at the hands of some very experienced riders went on to run well over 300 after returning to a pneumatic tire.
Their have been failures with tires also but is was a combination of old age and the misuse of a design that was intended for something else to start.
Sadly, most of the failures of that type go mis or under reported and that dooms the new comer to repeat.
This is where the experince level and intent of the sanction body rulers begins to really show.
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OBTW : Lean angle and the ability of the bike liner to counter act the forced of invisible cross winds is all you have to stay up.
A top side rider uses body English as a natural reaction that a liner driver does not have.
Some of the reasons bike liners crash more is they are subject to the track conditions more than an open bike because of the aerodynamics.
The open bike rider scares easier and won't take it as far.
Rider protection from themselves is one of the main objectives of a ruling body.
Failed innovation, revelation ,and correct resolution are not shared often enough .
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The real problem is not weight and balance but lack of contact patch and the required lateral traction needed to keep a MC in hand.
They work on jet cars in the dirt because they displace the surface to get the required side bite.
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You know how Craigs wheels/tires are built and looks?
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Yes I do and have seen it run on both salt and the dirt.
The mark it leaves in the dirt is the only corrective steering bite he has and other than altering the aerodynamic shape to steer it he has nothing.
It is easy to forget the tremendous power that has to be devoted just to keep it on the ground.
A transonic shock wave is equal on all sides.
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The trick is, to use a very thin rubber layer at last on the outside of the carbon base. To Craigs information is this not a problem. It was discussed to do this for the SoA, but at last they done the pure carbon for the ground contacting surface.
Using this system on a streamline bike wouldn't be a problem, the size and the weight could be optimize with the computer.
And again, the problem with solid aluminium wheels on bikes was weight and balance problem. Not the balance of the wheel, the balance of the bike, due to weight on the wrong place of the wheel.
Best example was the Easy Rider solution, same problem on the Pea Soup Andersen's Monster.
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Don Vesco tried bonded Polyurathane on the contact surface of a very light wheel assembly and it failed.
He did it with the best methods available from the industry.
The surface in contact with the dirt that displaces the surface to get a bite doesen't care if it is aluminum ar a laminated fibre.
A pnenumatic tire for those speeds and required down loading has not been developed.
It is a simular problem with wheel driven vehicles that are for the most part going half the speed.
I guess you just had to be there when the first edition of the Herbert liner sat on the line at idle and while the wheels spun on the salt it failed to procede.
Th English rocket bike that went over 300 mph ran to the limit of the available pneumatic tires and couldn't get past towing speeds with the aluminum front wheel.
A good indication of the forces involved would include a weight comparison of the assembly.
When it did move , Vesco turned out in about 1 mile and said it was not going to work.
It came back to the next meet that year and now with the available LSR tires it unmasked other problems.
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Ok Jack , I get it now. I ran some of my models ( computer) and slowly decreased the coefficient of friction of the tires and I see what you mean, The solid wheel wont work because there is nothing for it to bite into when you need a lateral or centering force, the surface is too hard to get the necessary interlocking. Also I think the gyroscopic effect of a solid wheel would be a big problem. So the million dollar question is where do you get a set of 400MPH motorcycle tires and what is Sam going to do???
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The race for fastest MC has been pushed to 400mph and as is the problem with most LSR stuff the tires remain the limiting factor.
The Supersonic barrier presents a whole other set of problems for a land vehicle that have not been mastered yet.
Even water gets harder the faster you go.
With all the desire expressed for a suitable tire to accommodate 1 MC liner, where is the concern for the others ?
Am I supposed to believe that is the limiting factor for just one ?
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The surface in contact with the dirt that displaces the surface to get a bite doesen't care if it is aluminum ar a laminated fibre.
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Jack, you be right with this comment, but I'm not talking about laminated fibre.
The shown layer, which touch the ground is RUBBER, normal rubber as an "average Joe" tire :wink:
Also important is the "profile" of the wheel to eliminate the gyroscopic effect - this is possible.
I discussed my idea a while ago with some tire specialist (when this new Michelin solid tire/wheel was coming out - this concept is still in testing, but the producer is still interest to get it in production...wait and see).
They said, the only problem with the idea is just the cost......they calculate about 10 000+ dollar for each wheel.
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mr pork pie
what was the pea soup anderson car?
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Some interesting related thoughts on the relationship of rubber and friction by Kevin Cameron can be found on the top of page 111, Dec. '06 issue of Cycle World Magazine.
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mr pork pie
what was the pea soup anderson car?
Slick Gardner, a "big" farmer in Buellton, CA, there where the Dry Lake Hall of Fame is, bought the 1967/68 Green Monster from Art Arfons, the three times world land speed record holder from Akron/OH.
He modified a little bit the fin and done the car on solid aluminium wheels - he copied simple the shape of normal tire for the aluminium piece.....
He run the car at Bonneville twice without success but some wet pants...... :wink:
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Here a picture of the running Pea Soup :wink:
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The last I saw of the car was it was on display at the entrance to the Peterson Museum in L.A.
While the power was often compared to a rubber balloon full of air and just let go, the ride was just as scenic.
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I have noticed from pictures that Yacoucci/Costella run aluminum front wheels on their streamliners. Does anybody know how are they making them work?
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A car is quite a different animal and not dependant for as much side thrust in the front steering wheels to stay upright.
The power is supplied with enough rubber tired traction working with the aero design and running surface to produce the speeds.
While it might work well enough for a car that was a very small area in front of a very long wheelbase, shorten it up to 1/2 or try It on a roadster and it will fail.
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I believe Jack's 5050 motorcycle 'liner also has an aluminum front wheel
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As an iggernut person, I suspect that rubber tire treads do flex and deflect a bit (however miniscule they might flex and however little rubber is left after shaving) whereas metal ones don't. Do you think the two types of wheels might feel and act a bit different no matter how much you try to get metal to feel like rubber? This is from a person (me) that definitely does not know any better, but it looks like Jack do.
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Shaving is only meant to reduce the unsupported rubber mass and associated failure.
The action against the surface is the final objective.
With increased speed the demands are greater and what might seem to work at a reduced speed, is quite different when pushing that same rope twice as fast.