Trailering

[dacheedah]

Well at least no one said anything about oil or the first gen second gen thing

[Condor]

Or maybe you been dipping your toe in the wind stream a bit much?

 

Well at least no one said anything about oil or the first gen second gen thing

 

 

It's never too much. Nothing like a good toe dip to keep things cool down there. You should try it sometime, it's never too late. It's refreshing..... At least we're off the sarcasm.. veiled threat thing.... Now about that oil???

[dynodon]

It's never too much. Nothing like a good toe dip to keep things cool down there. You should try it sometime, it's never too late. It's refreshing..... At least we're off the sarcasm.. veiled threat thing.... Now about that oil???

 

Yep, good to be off the oat eating, NASCAR denying (Geeze), hot kitchens, more NASCAR and never too late dipping. Yep, you sure let the sarcasm go.:rotf:Been fun, it's your turn now.

[Condor]

Yep, good to be off the oat eating, NASCAR denying (Geeze), hot kitchens, more NASCAR and never too late dipping. Yep, you sure let the sarcasm go.:rotf:Been fun, it's your turn now.

 

Oat eating?? (sic) Not sure I know what you're talking about. Something to do with NASCAR???

[dynodon]

Plus running at 80mph towing a trailer and the bike drinks fuel like a horse eating oats.....

 

there you go, your comment about Oats!

[Condor]

there you go, your comment about Oats!

 

Wow it's tough dealing with a detail man... You must go back and reread each and every post for your material. I guess the oat comment must have offended you??

But since you brought the subject up. Do you want to explain to me your wisdom of comparing two cars...or more... with minimum ground clearance, drafting down a straightaway at 200+mph bumper to bumper, with the air lift effect on a motorcycle trailer, 12 to 14 inches off the ground being pulled down the road at 75+... 4 to 5 feet behind the bike. Common sense just might tell you they are not the same thing.

My first post was a friendly expression of an idea. Sometimes I get a little 'country' when trying to make them that way. Hence the oat comment about fuel consumption.

As far as sarcasism goes, you might look in the mirror. Your "Ever heard of NASCAR and drafting?" (sic), might just be interpreted as exactely what you were complaining about, and what I took offense to. Sorry but that's the way I respond when someone starts to get smart ass with me.

So... this is going to be my last post on this tread.. Take your best shot in your response. I'm out of here....

[dynodon]

Wow it's tough dealing with a detail man... You must go back and reread each and every post for your material. I guess the oat comment must have offended you??

 

But since you brought the subject up. Do you want to explain to me your wisdom of comparing two cars...or more... with minimum ground clearance, drafting down a straightaway at 200+mph bumper to bumper, with the air lift effect on a motorcycle trailer, 12 to 14 inches off the ground being pulled down the road at 75+... 4 to 5 feet behind the bike. Common sense just might tell you they are not the same thing.

 

My first post was a friendly expression of an idea. Sometimes I get a little 'country' when trying to make them that way. Hence the oat comment about fuel consumption.

 

As far as sarcasism goes, you might look in the mirror. Your "Ever heard of NASCAR and drafting?" (sic), might just be interpreted as exactely what you were complaining about, and what I took offense to. Sorry but that's the way I respond when someone starts to get smart ass with me.

 

So... this is going to be my last post on this tread.. Take your best shot in your response. I'm out of here....

 

Well, since you love to quote and quote, and post sarcastic comments and such, your latest reply is just more of the same, so look in the mirror my friend! Yes, there is some comparison to NASCAR drafting and going down a highway at 60+ mph. You made the point that there is a LOT of air out there with your foot in the wind comment, so you can't now claim that there is no air effect when you tuck in behind something. Trucks do it all the time at 60 mph, and it makes a big difference. Hyper milers with their Prius cars and more know that you don't have to be just inches from the vehicle in front to get some benefit. A trailer, lower than the bike, about the same size frontal wise, and tucked just a few feet from it WILL have some draft benefit. If you can't see that, then too bad, but sometimes the truth hurts! Oh, and I never said they were the "same thing".

 

You asked where I got the Oat comment, I made a simple quote of your own words without comment or more sarcasm (what DO you have against NASCAR anyway) and your comment shows you didn't want to just talk, but argue.

 

As for sarcasm and where it started, I turn the mirror around to you. You made the comment about foot in the wind....you don't see any sarcasm there? Like you would expect an experienced rider to never know there was any wind out there? Well, I did respond in a kindly manner and with similar sarcasm, but you started it. Look at your own comments before you fire, you may find a misfire!

 

That's not my best shot, but a good one.

[Guest tx2sturgis]

I dont have a wind tunnel to verify this, but the much lower speeds of our bikes on the highway vs a racecar at 190 mph means that the 'drafting' effect is much less beneficial with an aerodynamically dirty bike pulling an aerodynamically dirty trailer. I have seen as much as a 25-40% drop in fuel mileage pulling certain trailers, sometimes in a crosswind, at highway speeds.

 

The weight of the trailer has little effect, (within reason) and the rolling resistance of most of these units is pretty low. The extra fuel used is nearly all due to the aerodynamics of the combination.

 

Some other smaller trailers dont effect the mileage as much, such as the small single-wheel trailer I built last year, and probably the small uni-go style trailers also.

 

Trundling along at the modest speeds of 75 mph, the air behind a bike does have the time to cause vortices right behind the bike, and the trailer runs smack into that. The airflow behind a motorcycle is not clean, and the trailer bumps right into it. Its like the bike's motor has to overcome the dirty aerodynamics of TWO motorcycles. Most 2 wheel trailers have lots of parts poking out in the windstream: wheels, fenders, axles. It takes horsepower to push that stuff thru the air, even IF there was a motorcycle in front of it parting the air for the body of the trailer.

 

At 190-200 mph, the aerodynamically superior NASCAR units dont allow much air to fill in behind the first car before the second car thats drafting it punches thru. Not so with our more modest speeds and less efficient airflow.

 

Not taking any sides, just my 2 .

 

 

 

Edited June 11, 2012 by tx2sturgis

[dacheedah]

Ok lets change this to a thread about oil and have some real fun.

[dynodon]

I dont have a wind tunnel to verify this, but the much lower speeds of our bikes on the highway vs a racecar at 190 mph means that the 'drafting' effect is much less beneficial with an aerodynamically dirty bike pulling an aerodynamically dirty trailer. I have seen as much as a 25-40% drop in fuel mileage pulling certain trailers, sometimes in a crosswind, at highway speeds.

 

Sturgis, Agreed, and although you didn't say it, I would point out that I never said that the two (bike/trailer vs drafting on a race track) were the same, just that there was a similar effect.

 

The weight of the trailer has little effect, (within reason) and the rolling resistance of most of these units is pretty low. The extra fuel used is nearly all due to the aerodynamics of the combination.

 

Agreed also, again, within reason. I pulled a box trailer 24' that weighed about 4000 pounds, and when I put a 4000 pound car in it mileage didn't go down significantly but it did go down.

 

 

Some other smaller trailers dont effect the mileage as much, such as the small single-wheel trailer I built last year, and probably the small uni-go style trailers also.

 

agreed, and although I am not familiar with your homebuilt, I would bet the Uni-go has an empty and loaded weight almost half that of a regular trailer.

 

 

Trundling along at the modest speeds of 75 mph, the air behind a bike does have the time to cause vortices right behind the bike, and the trailer runs smack into that. The airflow behind a motorcycle is not clean, and the trailer bumps right into it. Its like the bike's motor has to overcome the dirty aerodynamics of TWO motorcycles. Most 2 wheel trailers have lots of parts poking out in the windstream: wheels, fenders, axles. It takes horsepower to push that stuff thru the air, even IF there was a motorcycle in front of it parting the air for the body of the trailer.

 

A bike does punch a pretty dirty hole in the air, but there is still a low pressure area behind it, especially just a few feet behind. I would hope you would agree that the wind on a small (I am thinking my Bushtec roadstar for example) motorcycle trailer is less when behind the bike, than if it could somehow just go highway speeds by itself. If you don't agree, that is OK, neither of us has a wind tunnel, maybe someone can find some test someone else has done?

 

At 190-200 mph, the aerodynamically superior NASCAR units dont allow much air to fill in behind the first car before the second car thats drafting it punches thru. Not so with our more modest speeds and less efficient airflow.

 

Again, agreed, never said they were the same.

 

Not taking any sides, just my 2 .

 

No offense taken, your reply is appreciated.

 

Quoted your note so it would be easy to follow the answers.

[Guest tx2sturgis]

 

 

 

 

 

A bike does punch a pretty dirty hole in the air, but there is still a low pressure area behind it, especially just a few feet behind. I would hope you would agree that the wind on a small (I am thinking my Bushtec roadstar for example) motorcycle trailer is less when behind the bike, than if it could somehow just go highway speeds by itself. If you don't agree, that is OK, neither of us has a wind tunnel, maybe someone can find some test someone else has done?

 

 

 

Low pressure does not always equal low resistance, especially if that airflow is very turbulent.

 

Although it might SEEM to make sense, I dont necessarily agree that the trailer is slipping along with less drag in a dirty airflow than if it was in a 'clean' airflow. Sometimes just riding behind another rider is a lot more difficult because of the dirty air flow. I will drop back 50 or 100 feet and the clean air slips a bit more easily around the bike. Or so it seems to me.

 

And if you figure in the crosswinds, the drag is increased a LOT on the overall combination, in my experience.

 

But even assuming a calm wind and no sideways vectoring, I believe that an aerodynamic trailer is a misnomer because of the 'dirty' air it must 'fly' thru. I'm not saying we should all pull a big boxy rectangle, but if you believe that the manufacturer wind-tunnel tested your trailer behind a bike, I will disagree until I see proof otherwise. Even then, I doubt they could pronounce their trailer somehow ignores the dirty airflow and slips thru that air in an efficient manner.

 

I would tend to think that a nice wedge-shaped or curvy trailer would slip thru clean un-interupted air EASIER than it does behind a bike. But this is a guess, and if proven otherwise, I would certainly concede.

 

I think the 3 or 4 feet between the bike and the normal trailer is enough of a partial 'vacuum' that the dirty air that slips in there is going to RUIN the aerodynamic benefit of the trailer, no matter HOW swoopy it looks.

 

Its all about marketing, not engineering, when your selling a $3000-$5000 trailer.

 

I could be wrong, and I have no 'ego' in this debate, so if we have an engineer that says I'm wrong, well so be it. But hes gonna have to prove it in a windtunnel!

[dynodon]

Sturgis, I would think that even in dirty air, a more "aerodynamic" trailer would still fare better than a brick, could be some odd interaction, but still, an airplane will behave better in dirty air than a brick!

 

I have no idea if anyone, even the manufacturer has done any wind tunnel tests on the Bushtec trailers, but I am 100% confident it will slip through the air better than some of the boxy trailers that sit much higher. Having towed both types myself, and having a few friends that have done so with both types, we all agree, that the Bushec or similar looking trailers behave so much better behind our bikes that there is no argument which we want to tow under any conditions. Not scientific, but real world results.

 

As for dirty air behind a motorcycle, I have felt it, but I don't ride 3 feet behind bikes at 70 mph for example. I doubt if many or even any riders other than racers have done this. So without wind tunnel testing, I will still go with there being less wind on a trailer 3 feet behind a bike, than anything 10-20 feet behind it. For sure motorcycle racers know and take advantage of drafting and although their bikes are much more aerodynamic than my Wing, and the Wing at legal speeds is much slower, the effect is still there.

 

Be fun to get some real world tests.

[Guest tx2sturgis]

Sturgis, I would think that even in dirty air, a more "aerodynamic" trailer would still fare better than a brick, could be some odd interaction, but still, an airplane will behave better in dirty air than a brick!

 

 

Drop a un-piloted brick into a severe thunderstorm with tops at 40,000 feet and then drop an unpiloted Cessna 172 or even an Airbus 380 thru that same storm. See which one makes it through undamaged everytime. (not even counting the sudden stop at ground level)

 

The brick will behave WAY better than the airplane. I promise you.

 

So, things are not always what they seem. But, re-read what I said earlier. I said that I dont believe we should all pull boxy rectangular trailers. Handling is the reason for that.

 

I have no idea if anyone, even the manufacturer has done any wind tunnel tests on the Bushtec trailers, but I am 100% confident it will slip through the air better than some of the boxy trailers that sit much higher. Having towed both types myself, and having a few friends that have done so with both types, we all agree, that the Bushec or similar looking trailers behave so much better behind our bikes that there is no argument which we want to tow under any conditions. Not scientific, but real world results.

 

But I wasnt originally talking about 'handling'...where in my previous post did you see that?

 

I was talking about drag, and the effect on fuel mileage. I wasnt equating handling to coefficient of drag.

 

 

If you want to argue about the handling, the effect on the rider, on stopping, cornering, and so on, then you and I will probably agree on a lot of it. But my original point stands.

 

And that is:

 

Most trailers that we pull with our bikes are gonna affect fuel mileage, and mostly because of the dirty air they have to pass thru. It causes aerodynamic drag. Period.

 

 

Edited June 11, 2012 by tx2sturgis

[dynodon]

right, you didn't talk about handling, I didn't say you did. I didn't even mention that word. Shouldn't be any problem there, but handling or some sort of behavior was part of some of the other conversations, and if a trailer is getting disturbed by dirty air, it will "handle" different, it will move around, it will pull the motorcycle, even a heavy Wing, side to side, and up and down (as it hits bumps.)

 

Where am I arguing? I didn't argue, just comments.

 

My comment was about my experience with two different types of trailers. I didn't put any words in your mouth. Don't assume something that isn't there. So all is good...right?

 

As for the airplane thing, I don't believe anyone has talked about dropping trailers from a height. My comment was how an airplane would behave in dirty air (and OK, let's just say it is actually flying, not falling uncontrolled, like a trailer behind a bike is controlled, not falling) and I am hoping you can agree that the airplane will do better than a brick. or brick like airplane if you will. I can put a huge number of qualifiers on but let's just not go there. OK?

 

Best wishes, I am not arguing, you can if you want to, but I don't see the point. How about a civil discussion? It does happen here, just have to not read too much between the lines.

 

I will agree to disagree that it is aerodynamic drag...period (your words) that "mostly" causes fuel consumption to increase. I submit it is as much friction and increase in weight. of course this depends on the trailer towed. If you are towing one that is flying a billboard sideways (big side facing forward) sticking way out beyond the bike, then, OK, MOSTLY it would be aerodynamic drag hurting mpg. My opinion, you are welcome to yours.

[wes0778]

For what ever reason, or combination of all, my H/F Tag Along reduces my gas mileage 2-3mpg, best I can tell.

[dynodon]

For what ever reason, or combination of all, my H/F Tag Along reduces my gas mileage 2-3mpg, best I can tell.

 

I get the same result with my 1800/Bushtec, about 2 mpg less.

[Brake Pad]

"I have no idea if anyone, even the manufacturer has done any wind tunnel tests on the Bushtec trailers, but I am 100% confident it will slip through the air better than some of the boxy trailers that sit much higher. Having towed both types myself, and having a few friends that have done so with both types, we all agree, that the Bushec or similar looking trailers behave so much better behind our bikes that there is no argument which we want to tow under any conditions. Not scientific, but real world results."

 

I find that, having straight factory pipes on the bike, you feel the buffering from the exhaust pipes, getting turn-down pipes will eliminate this. But having the trailer on during a wind storm keeps you on the road, defiantly holds the back end down, you don't get blow around as much. ( I lose about 4 miles a gallon when pulling two up, with the loaded trailer at 65-70) But on secondary road, 55-60 I get 155 to 162

[dacheedah]

Video, I wanna see the video of the brick vs Cessna.

I remember when I was in the service and they volunteered me to exit a perfictly good aircraft in flight. Through all the training and even over the LZ they drop a bowling ball and a bearing ( not a bearing from a harbor freight it would have needed repacking) from the back. That ole gravity will pull objects at the same speed, if dropped at the same time they will impact at the same time. the only thing that changes that is aerodynamics, the parachute just changes the aerodynamics and makes it a controlled decent, if everything works correctly.

On the PD, while in crime scene investigators course, we hit another version of that physics experiment. If you fire a bullet from a gun aimed parallel to the flat level ground and drop a bullet at the same time the gun is fired they will strike the ground at the same time. The fired bullet will travel much farther but it's energy is forward, gravity will pull it down at the same speed ( even though it's turning).

Aerodynamics changes the amount of resistance the object has to being pulled at a given speed. The wind tunnel test would be awesome to see at what distance behind the RSV is optimal for pulling a trailer, what effect the taller windshield has . . . if anyone argued that it is unimportant at the speeds we travel then why do car and truck manufacturers spend so much time in wind tunnels improving gas mileage. Why do we notice a wall of wind passing a semi, because it is there. Mythbusters has already done the drafting thing http://green.autoblog.com/2007/10/28/mythbusters-drafting-10-feet-behind-a-big-rig-will-improve-mile/ the question becomes what is the best tongue length behind the bike to place the trailer, cooler . . . If you look at their results it improved as they got closer to the truck until they were very close then it changed to worse. So what is the best distance???

Now somebody out there must have access to a wind tunnel and a video camera, an rsv, a couple trailers where we could play with the entire tongue length and design. It would make an awesome meet and play day. . .

Edited June 12, 2012 by dacheedah