GL1800Riders Forums banner

1 - 20 of 30 Posts

·
Registered
Joined
·
2,984 Posts
Discussion Starter #1
Have any of you installed a lower, smoother, more aerodynamic body on your Harbor Freight, Aluma or PiggyBacker frame? Pictures? Suggestions? Just thinking of an improvement project.
 

·
Registered
Joined
·
2,984 Posts
Discussion Starter #2
Nobody? Well, maybe I'll be the first. I'm thinking about the Thule cargo box, or maybe the Rage Powersports topper. To reduce drag, these need to be mounted with the larger end FORWARD. That way the airflow is SMOOTHER off the back.
 

Attachments

·
Premium Member
Joined
·
12,496 Posts
..Suggestions? .
.. egg shaped..

I was amazed that I always got better gas milage while towing my little Uni-go..
..I think it did a great job of re-attaching the airflow behind the otherwise very un-aerodynamic goldwing (the chopped rear on the bike is terrible).

Dennis
 

·
Registered
Joined
·
3,875 Posts
Someone on here built a trailer with one of the long Thule carriers-- but mounted it with the sloped end forward. Nice looking trailer.
 

·
Registered
Joined
·
49 Posts
I'm not sure how much aerodynamic difference one would see with one of these flatter cargo boxes by turning it around. If any it would be very small in my opinion. I just finished mine last week and took it for its maiden voyage Saturday. I'm very happy with the outcome..

trailer.jpg
 

·
Registered
Joined
·
52 Posts
I wouldn't worry too much about the aerodynamics and focus on the looks. Trailers draft in the wake of the bike and probably don't create much additional drag. The goldwing is an areodynamic pig especially when you add wind wings, windshield vents, flags and other goodies. Get a trailer that holds what you want to take along and looks good to you. If you're trying to save a buck consider staying home!
 

·
Administrator
Joined
·
3,793 Posts
It shows.
I'm perplexed by your comment. Do you have a trailer you'd like to brag about, or are you just a roadsign shooter?

I have a pretty expensive trailer and I really like it, but I'm not about to snipe at anybody for their choice of either wife, motorcycle, or trailer.

Glen
 

·
Registered
Joined
·
5,788 Posts
Snownut, That looks good to me, I've seen some alot worse that cost a lot more!
 

·
Registered
Joined
·
957 Posts
I'm not sure how much aerodynamic difference one would see with one of these flatter cargo boxes by turning it around. If any it would be very small in my opinion. I just finished mine last week and took it for its maiden voyage Saturday. I'm very happy with the outcome..

View attachment 38773
I'm thinking about building one of those for hauling extra stuff around on short trips or trips where my camper isn't needed , just thinking about a flatbed version to carry icechest and bow case . :lol:
 

·
Registered
Joined
·
2,984 Posts
Discussion Starter #13
I'm not sure how much aerodynamic difference one would see with one of these flatter cargo boxes by turning it around. If any it would be very small in my opinion. I just finished mine last week and took it for its maiden voyage Saturday. I'm very happy with the outcome..

View attachment 38773
That's a nice looking trailer you got there.
What kind of cargo box did you use?
 

·
Registered
Joined
·
2,984 Posts
Discussion Starter #14
I wouldn't worry too much about the aerodynamics and focus on the looks. Trailers draft in the wake of the bike and probably don't create much additional drag.
You may be right, Jerry, but my initial impression on my first ride with the PiggyBacker was a feeling of wind drag. I dropped my wife off, hooked up the trailer and took a spin. It didn't feel like weight, it felt like wind resistance. I actually think a tall thin trailer might connect the wind coming off the back of the Wing even better than a sleek, low trailer. Sadly, nobody makes a box shaped like that.

I wonder where I could get pictures of the Wing's actual aerodynamics?
 

·
Registered
Joined
·
52 Posts
CC, if you get a tall thin trailer you might save a nickel on gas buy you'll spend a dime on head ache pills because you'll be unpacking everything trying to get to what you have on the bottom. I still think you should get what you like, in a size that holds what you want and forgetaboutit!
 

·
Registered
Joined
·
1,403 Posts
Short answer is 'no'

I haul my luggage and whatever... that's why I bought it.

Now if I hauled surf-boards or a casket, I would have bought one of the $$$ - fill in the blank. :)
 

·
Registered
Joined
·
49 Posts
That's a nice looking trailer you got there.
What kind of cargo box did you use?
Its called a SportRack Aero XL.. Dimensions are 63"L x 38"W x 19"H.. I purchased it at Dicks Sporting Goods for $279. It opens from the rear and seems as well built as the other main brands I compared it to.

[h=1][/h]
 

·
Registered
Joined
·
5,844 Posts
I am always amazed at some rhetoric. I don't know anything about boats or dancing, so I would not be pulled into a discussion about those. I have designed a few aircraft and their parts however.








Most riders are not aware of the fact that about 80% of the horsepower used to cruise on the highway is to offset aerodynamic drag. However it is easy to prove by catching a day with fairly high wind that is parallel to a level stretch of highway and measure the distance that can be coasted from the speed limit down to the wind speed (say 70 to 25) both upwind and downwind.

In the wind tunnel, we use paint pigments to show the surface flow but a good muddy ride will do a fair job of flow visualization.






The yellow flow lines were added to the photographs because the size of the streaks is small when viewing the whole trailer. The closeups are shown to verify the yellow lines. If the muddy streaks look like they were broom swept, the flow is attached. If they look like dabbed with a sponge, the flow is not attached and is turbulent. What is ideal is that every molecule of air that we approach, is exactly where it was after we pass by. Any air that we bring along costs fuel.

The top speed of a motorcycle is almost entirely governed by its maximum air speed, not its ground speed. Not to mention any names but one of the Tailwind owners that has over 100,000 miles on their Tailwind was asked if they ever opened their Wing up with the Tailwind on and the reply was yes, once. I asked what the speed was and they said 128 GPS. I know this individual always had heavy loads. I never condone extreme speed pulling a trailer because hurting hurts. This is to illustrate that if the Tailwind did not have a very low aerodynamic drag coefficient there would be no way this could happen. Do not try this. Dynamic instability is a swift killer and many trailers will go into an unstable divergent oscillation at some speed that is unrecoverable by most riders. Efforts to correct divergent oscillation are usually out of phase and make it worse quickly and it is all over. It is absolutely one of those events where the juice is not worth the squeeze.

When gasoline was real, and cheap, we did not think much about wasting fuel. Now that there are much fewer BTUs in fuel and it cost 3 or 4 prices, we start to feel it on a 3,000 mile ride. That is even more pointed if we ride where the fueling places are sparse, especially at night.

If you are riding east or west between El Paso and San Antonio, 500 miles of that is 80 mph speed limit and there are places where you can go 100 miles between gas stations so even if you have more than half a tank of fuel, you dare not pass up a gas station if you are running a high drag rig.

The Tailwind trailer is a product of combining technologies of aircraft and suspensions. It has by far the lowest aerodynamic drag of any full size touring trailer, and the best ride. The ride of a trailer is easy to gage. Just open the lid, step in, and bounce. If it feels like jumping up and down on a concrete slab, that is how it will ride. It is kind of unpopular thing to do at a trade show, but the wheat and chaff are quickly separated in this way.

Jerry was by yesterday. He earns his living as a published photographer. Has thousands of dollars in photo gear in his Tailwind and says he never thinks about possibility of damage while in the Tailwind.





It is true that the Tailwind costs a lot to build and few are used by those that only pull a trailer one or two weeks a year. However, for the rider that would rather ride anytime, the Tailwind makes his addiction easy to manage. I have not had a car since 2003. Except when there is a requirement for more than one passenger, a bike with a Tailwind on it covers most transportation requirements in useable weather. My Tailwind demo was put on the road on July 1st of 2004 and has 285,000 miles on it now. It has never been serviced and is scheduled to have its first service at 300,000 miles. The recommended service intervals are 150,000 miles or 5 years. The exception is that if the axles are submerged, that a service is done in that year. I have two Wings, an 04 with 234,000 and a 2010 with 63,000. Neither are ever ridden without a Tailwind hooked on except when delivering a trailer and dead heading back.

There have been many rides in which there were Wing riders solo cross country in which I used less fuel per stop than some of them did and I had my Tailwind on.

I do not take issue with the riders that post about poor to mediocre trailers if they rarely use a trailer. However, for those who are not technocrats but are avid long distance riders, I would hate to see them led astray by well meaning comments and follow suit.

Human nature is such that if a person makes an uninformed poor choice in a purchase, they will often put lipstick on it and make believe it is good. There was the story of a cowboy who absentmindedly put salt in his coffee at a cafe one morning and gulped it down so he could get a fresh cup. As the waitress brought more hot coffee, he looked up and realized that everyone was looking to see if he would use salt again, so he did, rather than face the embarrassment of being thought a fool (in his mind).

Serious long distance riders are in the minority among Goldwing riders and riders in general, but for those that are, we make sure there is a solution for them. There is not a stronger aerodynamic trailer around either. It is made of eGlass prepreg with epoxy binder in 7781 cloth. The tensile strength of this aircraft composite is about 90,000 psi. Compare that with typical FRP glass trailers with a tensile strength of about 7,000 psi.



After pitching the riders off at an ice gouge in Alaska, this rig, with the throttle locked, cruised on its own until the road turned and it then went up and over an embankment and down into a 25 foot deep ravine. Bent the drawbar and put a small scratch on the edge of the lid.

Tailwinds are not for everyone, but those that have them are glad they do.
 

·
Registered
Joined
·
52 Posts
Thanks Tom, that's interesting. Have you done any wind tunnel testing with a trailer behind a motorcycle? It would be interesting to see that done using a Goldwing with 2 people aboard as that's how most of us travel instead of a trailer standing alone in the wind. Better yet, take that test to the road using some kind of scale in the tongue to measure the total amount of energy it takes to pull a trailer. Then compare a streamlined trailer with a boxy one. Then add a big cooler to the tongue, right in front of the cargo box like I have done. I'm guessing that big cooler really wrecks the airflow.

For what it's worth... I ride a 1500 wing 6,000 miles a year and tow a trailer about 25% of that. In my wildest dreams I could never rack up the kind of miles you talk about! So while all of this may be important to you and many others out there, it doesn't really matter to me. If I pull an inefficient trailer and lose a couple of miles per gallon vs a more efficient one it's only going to waste $10 in fuel per season. I can afford that. You always say your trailers aren't for everyone and I appreciate that. Thankfully, we have a lot of good choices.
 

·
Registered
Joined
·
5,844 Posts
Thanks Tom, that's interesting. Have you done any wind tunnel testing with a trailer behind a motorcycle? It would be interesting to see that done using a Goldwing with 2 people aboard as that's how most of us travel instead of a trailer standing alone in the wind. Better yet, take that test to the road using some kind of scale in the tongue to measure the total amount of energy it takes to pull a trailer. Then compare a streamlined trailer with a boxy one. Then add a big cooler to the tongue, right in front of the cargo box like I have done. I'm guessing that big cooler really wrecks the airflow.

For what it's worth... I ride a 1500 wing 6,000 miles a year and tow a trailer about 25% of that. In my wildest dreams I could never rack up the kind of miles you talk about! So while all of this may be important to you and many others out there, it doesn't really matter to me. If I pull an inefficient trailer and lose a couple of miles per gallon vs a more efficient one it's only going to waste $10 in fuel per season. I can afford that. You always say your trailers aren't for everyone and I appreciate that. Thankfully, we have a lot of good choices.
Howdy, Jerry! As of last fill up this morning I have 936,863 miles of puling trailers with motorcycles and 1,138,869 miles of riding all together. There are interesting interactions involved when pulling a trailer. You may know that in high speed races in cars or even bicycle races that the leader of a twosome also can go faster with his chaser close behind. That effect is true while pulling a trailer also. Therefore using a strain gage on the drawbar of a trailer does not tell the correct story.


There is an old saying that life is what happens to you while you make other plans. In my youth I took vocational electrical training and planned to head that direction. Always heard that motorcycling was dangerous and for the less than savory people. Then my younger brother got a used James (The Famous James) but was too young to get a license for it and I got my drivers license at 14, so I could, with him riding on the back. He wore his hair in Duck Tails and I thought he might end up in jail if he did not quit hanging around with guys like that. Well he went to fight in Korea, has led an exemplary life, and has won Best in World in Maryland competition in carving birds of prey in wood more than once.

However, I became the addict. I was hopelessly addicted to riding a motorcycle. When I decided to get married, I had to do something to keep from being caged, so I designed and built a trailer for my new 1957 Ariel Square Four, my third new motorcycle. The trailer I built was an all aluminum camper with independent suspension,



A year later I traded the Square Four in on a new 1958 model. In 1959, Ariel and most of the British motorcycle manufacturers quit producing motorcycles. I continued to pull my trailer for 5 years and put 85,000 miles on it. I became afraid of not being able to get parts for the Ariel and traded it for a new 1963 BMW R69S, rated at the same 42 horsepower as the Square Four was. Deigned a nice hitch of Chromolly Tubing. Then I was devastated to learn that while the Square Four had 42 horsepower around the clock, the new Beemer only had 42 horsepower at noon on Tuesday.

I was thrust headlong into the world of aerodynamic drag. The new Beemer would slow down after accelerating in third and shifting into High (fourth) at full throttle. Because the Square Four was part John Deere, I did not know I was pulling a parachute for 5 years. I had hooked a race horse to a plow. That event changed the course of my life forever.

I went to my friend Ed Swearingen and said I had an aerodynamic drag issue with my trailer. http://www.airportjournals.com/Display.cfm?varID=0905003 Ed and I had hobby projects in Speaker System Development and building Pipe Organs. He pulled a napkin from the holder on the table where we were eating lunch and sketched an aerodynamic shape. I took his sketch and did an engineering drawing with modifications to fit the Camping use of it and built a new trailer at night at his aircraft works.



Although my new trailer was a half foot wider and 3 feet longer than my old trailer, it had nearly no drag and the 600 cc Beemer pulled it with ease. I became interested in aircraft design an in a couple years moved from being involved with Ed in building pipe organs to becoming head of his R&D, designing 90% of the moving parts on the Merlin and Metro aircraft and a large amount of the structure, the entire landing gear and hydraulic systems, etc. etc.

I went from there to form TEFCO and manufacture Trailers, Trailer hitches, ride off Stands, Fairing lowers, etc. for the Wing and Beemers in the 70s and 80s, and at the same time doing contract aircraft design. One customer, The Dee Howard Company, was about to loose a major contract furnishing thrust reversers to Learjet because of the new FAA Part 36 Noise limiting rules adopted by Congress. Either the Lear would have Bill Lear's claimed quieting nozzle or quit flying. That outsized nozzle would not allow thrust reverser to be installed. An alternative to this was to improve the aerodynamic performance of the Lear so it would take less thrust and climb faster above the departure microphones. However, Bill Lear, NASA, and Aeronautics R&D had all had their turn at bat to improve the Lear and abandoned their projects because none were successful. Dee Howard hired an Ex Boeing engineer to do a drag reduction program and each thing he did made the airplane worse. These included Banana Shaped Tip Tanks, zero length inlet for the nacelles, beaver tail tips on the tip tanks, etc. By that time I was acting head of his R&D and Dee asked me what should be done and I said we needed to determine what was wrong with the airplane.

He said OK. I pressure mapped the airplane and found what was wrong with it. I developed several aerodynamic changes and reduced the drag of the Lear by 20% and designed a new nozzle hat improved the trust by 2% at cruise. That still stands as the most improvement ever accomplished on a jet aircraft. I have done other similar projects since.

To answer your comment about ice boxes, etc., it does not make much sense do do anything to degrade the aerodynamics of the Tailwind, nor is it reasonable to immerse the icebox in the effluent of the radiator cooling flow and scrub the cooler with hot air. The Tailwind has a recessed floor between the wheels to provide space for the most massive cargo items where they will have the least impact on stability, and also to prevent high mass cargo from shifting aft which is very dangerous.

I totally understand your comment about not using a bike all that much. I never claimed to be normal but there are others, well a few, that ride more miles a year than I do. Dick Meyer does at least.

I would say this however. When you have a rig that performs so well, it ends up being used a lot more than one that doesn't. You rarely see a Tailwind chained to a tree at a rally although most of the other trailers are. Needing to run home and get the cage to go to the grocery store or cleaners or hardware store is not necessary and that can provide a lot of freedom when planning your day with a bike.

If you only lose 2 mpg at highway speeds by putting a trailer on, you are lucky. It is not unusual to see a 5 mpg penalty or worse for cargo trailers. With the diluted fuels we have now, you already lose about 2 to 4 mpg depending on the mix. That is a real farce but I dare not get into this topic.

There are other things to consider when reviewing trailers in addition to aerodynamics. Durability, safety, cargo damage, tire availability, handling, ease of use, loading and unloading, night visibility are just a few.

Speaking of 1500 Wings, I sold my last 1500 to a very long time friend. It is a 93 SE and had 257,000 miles on it. Now it has 298,000. Last weekend he won three categories at a rally. Oldest rider (81), Best looking 1500, and most miles on a bike. Below is that Wing and my 04 wing about the time my friend bought the 93. My 04 now has 236,000 on it and the 2010 has 64,000 on it. I have not ridden without a trailer in several years other than for bike service or when delivering a trailer. As an aside, I have used Dunlop E3s 70 series since they came out, abut 270,000 miles. They last about 20,000 miles per set with the front able to go further but I change them in pairs.





Thank you for your comments. Probably several riders wonder about these things but do not comment. I hope that you get to ride as much as you want.
 
1 - 20 of 30 Posts
Top