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Predictably negative. Craig has discussed all of your points at length over the last 4 years if you would read through the link I provided. Take it up with him. He is on several threads on ecomodders. The FIM ban was really done because the bikes in any given displacement class were just getting too fast for their crude tires and traditional street based racing tracks. He has proven the streetability of a streamlined motorcycle with thousands of miles of real world use. Alan rode his Ninja from California to Ohio and back for the MidOhio event. They ride all over. 120 liters of waterproof, lockable storage is pretty handy. And the bikes are no worse in crosswinds than the other "regular" bikes in the group. And much warmer and dryer in bad weather. The only reason no one builds a streamliner is purely aesthetic. It is not what people want to be seen on. And gas is still ridiculously cheap in the US even though we are blowing our grandchildren's inheritance. Craig's design is two steps ahead of the curve.
 

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You need to read my posts more carefully, nowhare did I say a streamliner was not a viable project. Just that it needs proper design. And then you need to read vetters coments more closley as he does indeed talk about streamlines moving around in the wind. Not saying all will only that it needs to be considered in the design. I am thru with this as it has become clear that you do not want a productive discussion on methods to address the issues ,only to insist that they do not exist. My first post was intended for the builder as I have a drag reduction theory that he may be interested in, however if he is to far along in the design process it would of no use. My intent is to help those that I can help and to learn from those who know something I may not. Go ahead and have the last word as from my point of view you have nothing more to offer on this subject.
 

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Your concerns are the same as always come up the first time someone sees a streamlined motorcycle and they have been discussed back and forth for a couple years. A good start would probably be here.
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Motorcycle aerodynamics, a slippery and windy, slope? - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
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At first look it appears that a side wind would blow you right over. I had the same reaction at first. And also argued against the feasibility of a tail. Until one of the more experienced engineers over there proposed that the only time there is a side wind is when the bike is parked. When traveling at highway speed, the head wind and the side wind combine to make the vectors of a wind direction that is just off of the nose. Making a big streamliner into a wing with an angle of attack. Which all normal bikes also have to a degree. Whose lift (side) is vented in Craig's design right at the area of maximum pressure differential by the opening in the fairing where your legs are. He tried this. He failed this when he fully enclosed one side of his bike. He opened it up again. I rode behind Alan at Ohio last year and his bike is impressively immune to buffeting as we approached large trucks. A very peaceful and quiet ride. On the road, it works. Although I will truncate my tail according to Kamm to save room in the garage.
I also found the phenomenon of a good motorcycle's ability to self correct and lean into the side vector of a cross wind fascinating from my observations while riding. These were argued back and forth and eventually explained by the same guy (thanks Ken Fry) as a simple, inherent action of the front steering geometry's trail translating the side force through gyroscopic forces and automatic counter steering into a corrective lean.
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http://www.cbr250.net/forum/cbr250-performance/1223-cross-winds.html
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It is easy to bench race an image. But Craig and Alan have trialed and errored and trialed again over the course of many years to prove a streamliner is ultimately much more road worthy and useful in everyday riding than a traditional looking bike. The fact that nobody wants it is irrelevant to the effectiveness. Most people in the US still want a four door pick up truck. The fact that racing rules still ban streamlining is also purely aesthetic. A streamlined 250 with a truncated tail would easily lap the field at will on any track.
I wish I had time to sit here and condense all the info but I don't. It is out there for anyone who wants to search and read.
 

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Discussion Starter #104
You need to read my posts more carefully, nowhare did I say a streamliner was not a viable project. Just that it needs proper design. And then you need to read vetters coments more closley as he does indeed talk about streamlines moving around in the wind. Not saying all will only that it needs to be considered in the design. I am thru with this as it has become clear that you do not want a productive discussion on methods to address the issues ,only to insist that they do not exist. My first post was intended for the builder as I have a drag reduction theory that he may be interested in, however if he is to far along in the design process it would of no use. My intent is to help those that I can help and to learn from those who know something I may not. Go ahead and have the last word as from my point of view you have nothing more to offer on this subject.
Thank you for you're input. I have considered several of these things, but really, as you mentioned, they need careful and selective testing analysis. Because I know better than to think I have all of the physics completely figured out, I have allowed for the ability to change my design after testing. For example, I plan to have a tail similar to the Vetter design, but I is removable. IF the first tail design does not produce the desired results, I can change it or remove it.

Sendler does seem to have a lot of experience, but don't let him rub you the wrong way. There is lots of room in this thread for ideas and discussion.
 

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Discussion Starter #105
I saw several posts about the general layout of my vehicle. I'm not sure what all I have covered before, but basically it is an elongated bike.
The CBR sets in the rear while the driver and passenger set in front of the engine, not over it like in many other designs. The total height is about 50 inches. The driver will have is feet beside the front wheel and above the seat. The driver sets about 11 inches off the ground.
The main thing about the bike that will immediately stand out is its size. It is long. Too long really. It will still fit in a parking spot, but ultimately will measure about 17 feet long.
It works fine for 2 people, with plenty of room inside (not a sardine can). There is no side door on the vehicle. The canopy will open and the driver can step in as if getting into a bath tub. It is nearly all aluminum and frankly is starting to look like a canoe! Most people think I am building a boat.
So far my weight is on target. I expect the additional weight to be about 200 lbs for a total weight of 550 lbs. Right now with 80% of the frame tubing complete, outriggers complete, and wheels attached, it weights 84 lbs and is amazingly rigid.

I should have a rolling chassis in the next 2 months or so.
 

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ok in that spirit here is a thought

We have 2issues working against us for high mileage. I will discount rolling friction) thermal inefficiency and aero drag.

The engine wastes heat 3 ways,
1 - thru the structure, and we can not do much about that.
2- thru the exhaust. a turbo will recover some energy but the compound engine is more directly aimed at range as it gears exhaust energy directly to the output shaft. These are not much use in this project as they add weight and complexity.
- the cooling system and we loose twice here because we waste heat energy and add drag pushing air thru the radiator.

Aircraft have long used pressure ducted cooling systems to reduce drag. One of the most efficient was way back in WW2 on the liquid cooled P51that ad a system of ducts and doors that had a worst case performance of 0 drag but some accounts claim a slight addition of thrust. Very possible as air enters the radiator and has heat energy added.

This leeds to why I was asking about your tail section design. If the aft section is pinched and flow seperation occurs a low pressure aera will likely form behind the vehicle. I have toyed with this idea for some time and plan to try it on one of the cars I am building. Carefully duct air from the area of highest pressure at the nose thru the radiator and exit the high energy expanding air out the back at the lowest pressure area. Hopefully there would enough energy added to eliminate the low pressure without resorting to a long tail section. Please excuse missing letters and numbers, I am afraid the cats have pounced on this keyboard 1 to many times.
 

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If I recall correctly, a gasoline engine runs its' best at a 14.7/1 air/ fuel ratio. If the computer does this, any fuel economy changes are going to be made by finding that magic spot in the RPM range where you're not lugging it (more throttle, no increase in speed), and winding useless revs just to appear cool. That "sweet spot" is gonna be a moving target depending on whether you're going uphill, downhill, or on level ground. The best way to save fuel is don't waste RPM's. And gearing too tall will cause you to have to use a lower gear to pull hills, etc... Stock gearing seems to be close. Just listen to your bike...let her talk to you...
 

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Discussion Starter #108
ok in that spirit here is a thought

We have 2issues working against us for high mileage. I will discount rolling friction) thermal inefficiency and aero drag.

The engine wastes heat 3 ways,
1 - thru the structure, and we can not do much about that.
2- thru the exhaust. a turbo will recover some energy but the compound engine is more directly aimed at range as it gears exhaust energy directly to the output shaft. These are not much use in this project as they add weight and complexity.
- the cooling system and we loose twice here because we waste heat energy and add drag pushing air thru the radiator.

Aircraft have long used pressure ducted cooling systems to reduce drag. One of the most efficient was way back in WW2 on the liquid cooled P51that ad a system of ducts and doors that had a worst case performance of 0 drag but some accounts claim a slight addition of thrust. Very possible as air enters the radiator and has heat energy added.

This leeds to why I was asking about your tail section design. If the aft section is pinched and flow seperation occurs a low pressure aera will likely form behind the vehicle. I have toyed with this idea for some time and plan to try it on one of the cars I am building. Carefully duct air from the area of highest pressure at the nose thru the radiator and exit the high energy expanding air out the back at the lowest pressure area. Hopefully there would enough energy added to eliminate the low pressure without resorting to a long tail section. Please excuse missing letters and numbers, I am afraid the cats have pounced on this keyboard 1 to many times.
We have several cats. :) I don't let them in my office :D

Per your discussion points on engine thermal waste:

1. I agree with the fact that the gas engine is very inefficient. Heat is the main loss and I also agree that it would take some "start from scratch" engine design to address it. Those discussions are elsewhere and progress is being made. Unfortunately, my budget is limited so the CBR is my starting point. I do plan to wrap the exhaust which may help. I know it will help the engine compartment temperature.

2. My design takes into account the drag from the radiator. I have not seen the aircraft design that you describe, but it sounds like the idea I came up with. In fact, the air inlet to the radiator is my only intentional air opening. The air will be controlled into and out of the radiator. The idea is to not allow "dirty" air into the bike enclosure as managing it is difficult without disturbing the outside air flow or causing drag.

The only area I considered leaving open in the tail is a 3" center section for vacuum on the engine bay. That may still happen, but it will be limited. I also considered making this opening adjustable in the cockpit.

My design is a little like a plane. It has a canopy for a windshield and has landing gear (outriggers :) )

Good points. Thanks for bringing them up.
 
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