A while back I had started a post about towing a trailer behind a bike... I cant seem to find it though, so anyways I figured I'd post my updates as to what I came to for a final design. This is my senior thesis project for My industrial design major and I'm pretty happy with my current result... I havent built the shocks yet in solid works, but everything you see has already been constructed and is headed to powdercoating tomorrow.
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/sdaf.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/front.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/ee.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/sneakpeak.jpg)
The Idea is to have the wheels pitch and roll with the bike, while the load stays in one place, allowing for tighter turns with a trailer. I have yet to build the body/box yet, any suggestions on how to do this would be appreciated, thanks.
Booster
I may be mistaken, but unless you have 2 vertical mounting points on the bike, the trailer won't pitch like how you have planned. Right?
Quote from: Big Rich on December 02, 2011, 01:05:38 AM
I may be mistaken, but unless you have 2 vertical mounting points on the bike, the trailer won't pitch like how you have planned. Right?
there's actually a bar that is welded between the two tie rods creating two vertical pivot points out of the ball joints, I couldnt get the cuts right to have solidworks allow me to mount it between the two rods.
or if you're talking on the actual bike, I'm in the process of building the hitch system, it will be similar to a one wheeled trailer mount to the rear axle, like this
(http://homepage.usask.ca/~deb666/images/one_wheel_sport_trailer/trailer_on_bike_1.jpg)
Ah, ok. Hope it didn't sound like I doubted you. Just wanted clarification. Thanks!
What material are you thinking about using for the body/box? Plastic, fiberglass, aluminum, etc?
It looks interesting (and complicated) but what does it do that's better than a standard trailer? Apart from even out the tyre wear.
It looks cooler.
Quote from: afterbooster on December 02, 2011, 12:59:34 AM
The Idea is to have the wheels pitch and roll with the bike, while the load stays in one place, allowing for tighter turns with a trailer. ...
Booster
that is what makes it better than a standard trailer.
very unique afterbooster! Good work! keep us posted please!
Quote from: afterbooster on December 02, 2011, 12:59:34 AM
A while back I had started a post about towing a trailer behind a bike... I cant seem to find it though, so anyways I figured I'd post my updates as to what I came to for a final design. This is my senior thesis project for My industrial design major and I'm pretty happy with my current result... I havent built the shocks yet in solid works, but everything you see has already been constructed and is headed to powdercoating tomorrow.
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/sdaf.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/front.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/ee.jpg)
(http://i25.photobucket.com/albums/c56/afterbooster/bike%20stuff/sneakpeak.jpg)
The Idea is to have the wheels pitch and roll with the bike, while the load stays in one place, allowing for tighter turns with a trailer. I have yet to build the body/box yet, any suggestions on how to do this would be appreciated, thanks.
Booster
that's going to get 'interesting' with a loaded trailer, after hitting a bump in a turn. i don't get why you want the wheels to lean, the mechanicals are cutting your payload width by a third or so, or making the trailer a third wider than needed depending on how you look at it.
that single wheeled coffin thing looks great for camping on a sport bike/dual sport. i wouldn't mind a trailer for some of our ride-n-camp dual sport trips. anything to get the weight down low instead of making me wheelie over every hump.
That looks pretty cool. I don't travel far enough to need one of those, but it would sure as hell make cross country riding that much more enjoyable.
Well had the show this weekend, I'll work on uploading photos of the show, but here was a checkpoint shot...
(http://i25.photobucket.com/albums/c56/afterbooster/PC090146.jpg)
Just curious, is there an actual purpose for having it lean, or is it just for the :wow: factor?
Quote from: comradeiggy on December 17, 2011, 08:25:31 PM
Just curious, is there an actual purpose for having it lean, or is it just for the :wow: factor?
safer...also if you're going into a turn at 45 60 whatever, and your rear tires are straight up and down(like current models) they dont get the same traction as your bike does, so the idea behind this is to get the same wear and tear from the rear wheels at the same time getting a trailer that holds the road as much as your bike does, it would allow the rider to ride like its not there. other than acceleration and braking, it'd be the same. Using two wheels takes most of the weight off of the hitch.
I'm not gonna lie, I highly doubt that this will have any effect whatsoever on handling, besides possibly making it a bit less stable. In your design I don't see anything that will keep the wheels vertical on straight roads, so I can see this thing wobbling all over the place, especially over crappy roads. As for it being better in turns, since the trailer body itself stays flat it won't change anything, since the CoG isn't shifting. The more I think about this the worse it sounds, from a design standpoint. I can actually see this thing flipping quite easily. When going around a corner, centripetal forces are going to push outwards, causing a moment about the contact patch. This torque will actually end up causing the wheels to tilt towards the outside of the turn.
the heck with the trailer, that is a Sweet lookin GS! :thumb:
Comrade, I had the same concern earlier - if you look at the second reply in this post, he mentions the vertical bar near the swingarm mount. That should keep it on the same side to side axis as the bike.
Afterbooster, obviously I'm no engineer. But I hope this design works really well for you. Are you taking it to a track or similar to test its handling characteristics? If you do, please report back here.
Quote from: afterbooster on December 17, 2011, 09:06:41 PM
Quote from: comradeiggy on December 17, 2011, 08:25:31 PM
Just curious, is there an actual purpose for having it lean, or is it just for the :wow: factor?
safer...also if you're going into a turn at 45 60 whatever, and your rear tires are straight up and down(like current models) they dont get the same traction as your bike does, so the idea behind this is to get the same wear and tear from the rear wheels at the same time getting a trailer that holds the road as much as your bike does, it would allow the rider to ride like its not there. other than acceleration and braking, it'd be the same. Using two wheels takes most of the weight off of the hitch.
you know, a flat tire profile would give even more traction.
also, is the trailer's outside push being directly transferred to the rear axle of the bike ? that might make for some interesting feeling when loaded and a spirited ride.
i haven't stayed in a holiday inn express in a while, so , you know ;-)
Interesting project and interesting concept!
Figuring out the correct geometry is actually fairly complicated.
I'm not sure all the variables were addressed, but only road testing and tweaking will tell...
I think that the lean in the trailer wheels will cause the trailer to try to turn in the same direction as the motorcycle is turning (camber thrust?)
.....only it looks like the trailer will try to turn "inside" (tighter radius) than the bike!
I would think you want the trailer to follow the exact same arc as the bike, so the trailer needs to steer opposite the bike...like long hook and ladder fire trucks which have rear steering....
Then there's caster, camber, toe in or toe out...tongue weight ..differential, etc...lot's of variables to make a nice riding trailer!
I guess the tires will wear longer as different parts of the tread contact in the turns vs the straights..
Flat tread will not provide any more "grip" than round cross section tires....
Cookie
As a design thesis I think it is great! It accomplishes the purpose. I think the concept has merit. And the rolling prototype looks very well done. Whether it's marketable, or even works well may be up for debate. But that's if it goes to market. I agree with twocool. Get it on the road and test! Oh, get a patent application going (unless the bastards at the university own all rights to any patentable work done while your are a student). Even if you fail at marketing it, you can profit if someone else can market it successfully.
Unfortunately this prototype needs a few modifications to get it totally road worthy... but I'm working with a mechanical engineer to have it ready by spring... I'm only an Industrial designer and its not worth risking my life or my GS on a "That looks straight to me" I'm in the process with the school of getting a patent for it. luckly it wasn't a sponsored project so I have all the rights to it. If you look on the yoke there's the bar in the back that has the few holes... this is used to adjust the aggressive pitch/camber of the trailer wheels, it could be more or less depending on the load that you have... I'm still waiting to get the pictures loaded, they're on a friends SLR. having the two wheels on the back actually reduces alot of the load on the back of the bike, the hitch weight actually is only 25 LBS.
Comrade, maybe when I get the show pictures up it will make a little more sense... also I have a video that I... well actually I can upload that now.
Now, what cha think?
also who wouldn't want to tow a Kayak with a GS, I mean seriously...
(http://i25.photobucket.com/albums/c56/afterbooster/PC170231.jpg)
Video
http://youtu.be/rcD0YOyHFys (http://youtu.be/rcD0YOyHFys)
What I like the best is the Kayak Mount!!
We do a bit of kayaking around here...always a PITA to drop off the kayaks at the start of the river and get a car to ick them up at the end......Bike might be easier so scoot back and for easily and easy to find a place to park while out paddling!
Cookie
@Cookie The opposite wheel locking on the long vehicles only works because the vehicle is rigid. A vehicle with a pivot between the mover and trailer would not work with counter lock steering. It would actually make it more difficult to control. When such trailes do have this, they are usually controlled by a person on the rear so the vehicle can get around corners without the trailer cutting it off too much.
@Afterbooster I look at your design and immediately think of a grader...
(http://www.deere.com/common/media/images/product/motor_graders/r4d007448_motorgrader_942x458.jpg)
As you can see, the front wheels can lean over even when the machine is going straight.
Your design will not change the centrifugal force on the trailer. It has two wheels and the same force will be applied to those two wheels whether they are leaned over or straight up and down. The most it will do is slightly share some wear across the tread - but - you are now exerting extra forces on your rotating hitch. And going but what I can see in the photo, that force will be directly applied to the axle bolts where you have it attached. And that includes forces needed to over come inertia (stationary or kinetic when leaning changes as you now need to stop the trailer leaning one way to bring it to lean the other way)
And, unless you also have a pivot point so the bike can be on a slightly different line to the trailer (like when a semi turns a corner) then those forces will also be applied to your axle bolts and will also make the bike unridable - while the trailer is attached the trailer will want to go straight and force that onto the bike.
That's how it looks to me.
Michael
Ok, I didn't realize that the tie rod was connected to the circular bar and that controlled the steering.
What makes this different from the grader is that the only way the rear trailer wheels can be tilted is with the bike actually being tilted... in terms of making it more difficult to steer, it would take no thought or action to make the trailer do this motion, the hitch is similar to the hitch like this...
(http://www.abiequine.com/_assets/equine_images/product_photos/products/rascal_pro_features_upclose/gr_hitch.jpg)
It pivots on the X axis allowing for slower turns when upright.
Quote from: mister on December 18, 2011, 12:13:30 PM
@Cookie The opposite wheel locking on the long vehicles only works because the vehicle is rigid. A vehicle with a pivot between the mover and trailer would not work with counter lock steering. It would actually make it more difficult to control. When such trailes do have this, they are usually controlled by a person on the rear so the vehicle can get around corners without the trailer cutting it off too much.
@Afterbooster I look at your design and immediately think of a grader...
(http://www.deere.com/common/media/images/product/motor_graders/r4d007448_motorgrader_942x458.jpg)
As you can see, the front wheels can lean over even when the machine is going straight.
Your design will not change the centrifugal force on the trailer. It has two wheels and the same force will be applied to those two wheels whether they are leaned over or straight up and down. The most it will do is slightly share some wear across the tread - but - you are now exerting extra forces on your rotating hitch. And going but what I can see in the photo, that force will be directly applied to the axle bolts where you have it attached. And that includes forces needed to over come inertia (stationary or kinetic when leaning changes as you now need to stop the trailer leaning one way to bring it to lean the other way)
And, unless you also have a pivot point so the bike can be on a slightly different line to the trailer (like when a semi turns a corner) then those forces will also be applied to your axle bolts and will also make the bike unridable - while the trailer is attached the trailer will want to go straight and force that onto the bike.
That's how it looks to me.
Michael
Yes the grader came to mind to me too....perfect example of the slanted wheels creating side force.
If you notice...the blade on the grader is angled (in this picture) in such a way as to try to pull the grader to the right.....the front wheels are leaning to the left, to create a left turning force equal to the blades right turning force....resultant is the thing goes straight.....
When you tow a trailer, the trailer always makes the turn tighter than the pulling vehicle. In fact, watch a tractor trailer trying to make a tight corner in a city....the cab ahs to go really wide and the trailer still cuts in close t the corner, often over the curb, and removing a street sign or two.
So I think in this motorcycle trailer design, the trailer will not only "track" to the inside (as all trailers do), but will also "push" to the inside...........making it difficult to ride the bike...
BTW hook and ladder are not always "rigid"...some articulate...and can drive straight down the street, with the vehicle at an angle..."dogging" as we call it!
The reason for the rear stearing is to negotiate city corners without running up on the curb....fron wheel and rear wheels travel same arc...Yes usually a rear driver........but ever see one of those huge flatbed heavy load load trailers, like the ones they can move a whole house on........they have wheels all over the place.......the whole mess is computer controlled so each wheel turns the correct, but different, amount to negotiate a turn.
Cookie
Ever see that Piaggio scooter with two front wheels? And its not a "trike" the whole deal leans just like a regular bike, but the two front wheels steer and lean in parallel, or almost parallel..
Cookie
http://www.geekologie.com/2009/06/vroom_vroom_piaggios_3wheeled.php
articuclated truck with rear steer...but requires rear dirver
http://www.geekologie.com/2009/06/vroom_vroom_piaggios_3wheeled.php
Quote from: afterbooster on December 18, 2011, 11:33:31 AM
Unfortunately this prototype needs a few modifications to get it totally road worthy... but I'm working with a mechanical engineer to have it ready by spring...
Well, spring is nearly over! How's it going!
Quote from: Paulcet on June 11, 2012, 01:17:25 PM
Quote from: afterbooster on December 18, 2011, 11:33:31 AM
Unfortunately this prototype needs a few modifications to get it totally road worthy... but I'm working with a mechanical engineer to have it ready by spring...
Well, spring is nearly over! How's it going!
well... The problem with working with a buddy is...more beer ends up getting drank then work being done, I've recently teamed up with a different engineer as of this past week...but with a deployment coming up, I dont know how much I can accomplish in two months and work... I'll keep on it though