ADVrider

Go Back   ADVrider > Bikes > Hacks
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-05-2014, 02:21 AM   #1
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
building a two-wheeled trailer to drag behind an ST1100

Picked up an ST1100 a few days ago and want to build a trailer to pull behind it. Something like an oversized Burley bike trailer for my dogs. Also want to be able to haul mountain bikes or a dirtbike, etc. Figuring that the maximum load will probably be under 450lbs, and don't have any delusions about taking this setup too far off-road.

Would be pretty easy to build a traditional hitch for this bike, but I've been thinking about mounting the trailer further forward on the bike. Like another swingarm mounted to the chassis, outside of the stock swingarm and rear tire. Thinking the main advantage would be the way the tongue-weight loads the suspension on the bike. Kinda like the difference between towing with a 5th wheel and receiver hitch. Has anybody ever done this? Somebody has to have tried it.

And... has anybody ever tried to adapt an electric trailer brake controller to a motorcycle? Not sure if the brakes on the bike will be adequate, and I'm just wondering what my options are if I need a little more stopping power. Or could maybe add a second master cylinder to the rear brake linkage and use a quick-release hydraulic coupling? Any other ideas?

Anything else I should be thinking about? Haven't given the suspension too much thought yet, but half torsion axles look like they might fit the bill. Being a two-wheeled trailer, would obviously need to allow it to pivot, but that's a pretty easy problem to solve.
jesusgatos is offline   Reply With Quote
Old 07-05-2014, 06:48 AM   #2
Bobmws
Curmudgeon At Large
 
Bobmws's Avatar
 
Joined: Jun 2005
Location: Same trailer, different park, FL
Oddometer: 1,198
Having pulled numerous trailers many thousands of miles behind two-wheelers I feel you are over thinking this issue. Tongue weight should be balanced by your load and should have little effect on suspension. I've always found the bike suspension to be more compliant with the load (camping gear, etc) shifted to the trailer from the bike. True even with my Bunkhouse camper loaded with vending gear ~600 lbs.!
Electric brakes are available on some of the MC campers,I believe they use a standard brake controller. Check Dexter axles, or E-trailer.
For stability at speed, tongue length should be at least 1.5 times the axle width. And learn to use your rear brake!
__________________
Bob Weis 04 K12RS - Hannigan Hack
Everything happens for a reason, but sometimes the reason is you're stupid and make bad decisions.
Photo's: http://s1077.photobucket.com/albums/w464/Bobmws/
www.earplugco.com

Bobmws screwed with this post 07-05-2014 at 06:54 AM
Bobmws is offline   Reply With Quote
Old 07-05-2014, 11:18 AM   #3
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
Have never ridden with a trailer, so your input is appreciated. My main concern is that with my dogs (and I've got four of them), they're going to move around and affect the tongue weight. Thinking that if the trailer mounting point is closer to the center of the bike, should be able to put more of the weight in the trailer forward on the tongue. Will load the front/rear suspension on the bike more evenly, right? Can't really see any downsides, except for maybe the added complexity?

jesusgatos is offline   Reply With Quote
Old 07-05-2014, 11:20 AM   #4
_cy_
Beastly Adventurer
 
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,893
coool .. climbing dogs like climbing goats
_cy_ is offline   Reply With Quote
Old 07-05-2014, 12:42 PM   #5
Bobmws
Curmudgeon At Large
 
Bobmws's Avatar
 
Joined: Jun 2005
Location: Same trailer, different park, FL
Oddometer: 1,198
Quote:
Originally Posted by jesusgatos View Post
Have never ridden with a trailer, so your input is appreciated. My main concern is that with my dogs (and I've got four of them), they're going to move around and affect the tongue weight. Thinking that if the trailer mounting point is closer to the center of the bike, should be able to put more of the weight in the trailer forward on the tongue. Will load the front/rear suspension on the bike more evenly, right? Can't really see any downsides, except for maybe the added complexity?

I understand the balance concept. Even if you build a sidecar type sub frame, the hitch bar itself will still act (be) a lever and place more downforce on the rear suspension. Perhaps heavier shock springs, and crank up the preload when hauling. A weight shifting load will be it's own problem, a longer trailer tongue will lessen that effect.
Nice dogs!
__________________
Bob Weis 04 K12RS - Hannigan Hack
Everything happens for a reason, but sometimes the reason is you're stupid and make bad decisions.
Photo's: http://s1077.photobucket.com/albums/w464/Bobmws/
www.earplugco.com

Bobmws screwed with this post 07-05-2014 at 12:49 PM
Bobmws is offline   Reply With Quote
Old 07-05-2014, 02:16 PM   #6
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
Quote:
Originally Posted by Bobmws View Post
I understand the balance concept, but if you attach in front of the rear wheel, how will you turn!?
Suppose I build a swingarm that replaces the center-stand, and it's constructed sort of like a bicycle fork, but laying down horizontal, and bent and contorted to clear the axle and exhaust and plastics, etc. Imagine this bicycle fork is complete with a headset and head tube from a bicycle. The headset is oriented so it's horizontal, and allows the motorcycle to lean. And then there is another vertical pivot-point behind the head tube that allows the motorcycle to turn. Should function similarly to a traditional hitch mounted behind the rear wheel, but the tongue weight would load the bike way further forward, at the point where the trailer is attached to the motorcycle chassis. Does that make sense?


jesusgatos screwed with this post 07-05-2014 at 04:23 PM
jesusgatos is offline   Reply With Quote
Old 07-05-2014, 06:18 PM   #7
leejosepho
Sure, I can do that!
 
leejosepho's Avatar
 
Joined: Jun 2011
Location: 200 miles north of New Orleans
Oddometer: 487
Quote:
Originally Posted by jesusgatos View Post
My main concern is that with my dogs (and I've got four of them), they're going to move around and affect the tongue weight...
To limit that shift in either direction and keep your tongue weight fairly consistent throughout the ride, you will have to move the trailer axle closer to the rear of the cargo area. Then...

Quote:
Thinking that if the trailer mounting point is closer to the center of the bike, should be able to put more of the weight in the trailer forward on the tongue.
What you have in mind makes sense, but you might need an engineer to help compute the load, design and minimum material dimensions for the lateral-roll "neck". I would likely make a horseshoe-shaped trailer tongue that widens like a wishbone by the time it gets to the axle, then add a linear "drawn tube" a couple of feet long and down the center at the front (with a cross member holding it at its rear) that will slide over the round draw tube of the "swingarm" that looks like a tuning fork and is attached to the bike.
__________________
He who so shall, so shall he who.

leejosepho screwed with this post 07-05-2014 at 06:27 PM
leejosepho is offline   Reply With Quote
Old 07-05-2014, 09:17 PM   #8
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
yeahyeah, no worries, am a pretty capable designer/fabricator. Was mostly hoping to get some advice from people who might have experimented with this kind of thing, as the geometry and some other details might require a little bit of trial and error to get right. Didn't give the geometry of this little Honda 50 pusher bike trailer thing as much attention as it deserved, and it was... well that was just a bad idea, and poorly executed.

jesusgatos is offline   Reply With Quote
Old 07-06-2014, 06:05 AM   #9
leejosepho
Sure, I can do that!
 
leejosepho's Avatar
 
Joined: Jun 2011
Location: 200 miles north of New Orleans
Oddometer: 487
Quote:
Originally Posted by jesusgatos View Post
...the geometry and some other details might require a little bit of trial and error to get right.
The part I cannot quite visualize in my mind is whether the vertical joint for turning should be ahead of or behind the linear joint for leaning...or maybe either above or below?!

Edit: I think the vertical pivot for turning should always remain perpendicular to the trailer axle, then have the linear joint below it to let the bike lean. Also, it should be relatively easy to add a mechanical surge brake controller in that same area.
__________________
He who so shall, so shall he who.

leejosepho screwed with this post 07-06-2014 at 06:20 AM
leejosepho is offline   Reply With Quote
Old 07-06-2014, 07:34 AM   #10
Bobmws
Curmudgeon At Large
 
Bobmws's Avatar
 
Joined: Jun 2005
Location: Same trailer, different park, FL
Oddometer: 1,198
Quote:
Originally Posted by Bobmws View Post
I understand the balance concept. Even if you build a sidecar type sub frame, the hitch bar itself will still act (be) a lever and place more downforce on the rear suspension. Perhaps heavier shock springs, and crank up the preload when hauling. A weight shifting load will be it's own problem, a longer trailer tongue will lessen that effect.
Nice dogs!
Quote:
Originally Posted by jesusgatos View Post
Suppose I build a swingarm that replaces the center-stand, and it's constructed sort of like a bicycle fork, but laying down horizontal, and bent and contorted to clear the axle and exhaust and plastics, etc. Imagine this bicycle fork is complete with a headset and head tube from a bicycle. The headset is oriented so it's horizontal, and allows the motorcycle to lean. And then there is another vertical pivot-point behind the head tube that allows the motorcycle to turn. Should function similarly to a traditional hitch mounted behind the rear wheel, but the tongue weight would load the bike way further forward, at the point where the trailer is attached to the motorcycle chassis. Does that make sense?
You grabbed my comment right before I changed it!
Common mechanism to allow the bike to lean is a swivel in the trailer tongue. The bicycle fork swivel under the bike will still have limits, and when, not if (DAMHIK) you drop the bike there is potential for frame damage. A trailer can create some unexpected forces when stopped, especially if facing downhill.
I still think you will have a lever effect on the rear suspension.
I think the idea of biasing the trailer axle to the rear will keep your shifting load weight effect to a minimum, and allow you to set the rear suspension for the load.
Just my 2 cents worth!
__________________
Bob Weis 04 K12RS - Hannigan Hack
Everything happens for a reason, but sometimes the reason is you're stupid and make bad decisions.
Photo's: http://s1077.photobucket.com/albums/w464/Bobmws/
www.earplugco.com
Bobmws is offline   Reply With Quote
Old 07-06-2014, 08:18 AM   #11
cleatusj
Dirt floor engineer
 
cleatusj's Avatar
 
Joined: Dec 2010
Location: Granbury, TX
Oddometer: 1,105
I used to pull a trailer with a RD350 that had a 3ft wide by 4 and a half ft long bed. I even hauled 400 lb of crushed stone but I really had to plan my braking. Now with 3 full size keg setups all I had to worry about was the gawkers. I pulled this trailer back and forth 10 miles to work for 2 years with no accidents, using a standard ball hitch.
__________________
In the stable now. '76 Moto Guzzi Convert Hack
'93 Moto Guzzi Calli 3 with Leaner turned rigid

Hack build: http://www.advrider.com/forums/showt...rt+floor+build
cleatusj is offline   Reply With Quote
Old 07-06-2014, 10:35 AM   #12
leejosepho
Sure, I can do that!
 
leejosepho's Avatar
 
Joined: Jun 2011
Location: 200 miles north of New Orleans
Oddometer: 487
Quote:
Originally Posted by Bobmws View Post
I still think you will have a lever effect on the rear suspension.
Think of the handles of a double-wheeled wheelbarrow being pulled behind you. The weight you lift there is only a vertical load with no leverage adding pressure at your heels. Then, your wrists represent the swiveling point-of-attachment at the bike -- a hard attachment there would cause the leverage you are pondering -- and your torso represents a left-right turning swivel...and now you only need a linear swivel below your swiveling torso -- Wanna dance?! -- so the bike can lean to either side without trying to twist the "tongue" (handles) and tip the trailer sideways. I have been thinking about the simplest way to possibly add a hitch to my own rig, and I think this is how I might do that after replacing the trailer's coupler with a piece of tubing to slide over the connection nipple that would first be swivel-connected at the bike.
Attached Images
 
__________________
He who so shall, so shall he who.

leejosepho screwed with this post 07-06-2014 at 11:24 AM
leejosepho is offline   Reply With Quote
Old 07-06-2014, 12:15 PM   #13
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
Quote:
Originally Posted by leejosepho View Post
The part I cannot quite visualize in my mind is whether the vertical joint for turning should be ahead of or behind the linear joint for leaning...or maybe either above or below?!

Edit: I think the vertical pivot for turning should always remain perpendicular to the trailer axle, then have the linear joint below it to let the bike lean. Also, it should be relatively easy to add a mechanical surge brake controller in that same area.
The horizontal pivot needs to be ahead of the vertical pivot in order to allow the bike to lean while turned (relative to the trailer). You got it right in your drawing.

Quote:
Originally Posted by Bobmws View Post
Common mechanism to allow the bike to lean is a swivel in the trailer tongue. The bicycle fork swivel under the bike will still have limits, and when, not if (DAMHIK) you drop the bike there is potential for frame damage. A trailer can create some unexpected forces when stopped, especially if facing downhill.
Would be better if the hitch on the bike swiveled though, instead of the trailer tongue. If the bike leans (or falls over) while turned (relative to the trailer) a swivel-joint isn't going to do much. Will still bind, and would not if it was designed/built the way I'm proposing. That's how all of our military trucks and trailers are set-up (swivel-hitches) and it works really well.

Quote:
Originally Posted by Bobmws View Post
I still think you will have a lever effect on the rear suspension. I think the idea of biasing the trailer axle to the rear will keep your shifting load weight effect to a minimum, and allow you to set the rear suspension for the load.
If the trailer is attached to the bike in front of the rear wheel there will not be any lever effect. The trailer will be pushing down on the front and rear suspension on the bike, all the time. The only leverage to be concerned about would be how the trailer might push the bike, especially when braking/turning. Not ideal to have the vertical pivot behind the bike's rear axle for that reason, but it's unavoidable.

Quote:
Originally Posted by cleatusj View Post
I used to pull a trailer with a RD350 that had a 3ft wide by 4 and a half ft long bed. I even hauled 400 lb of crushed stone but I really had to plan my braking. Now with 3 full size keg setups all I had to worry about was the gawkers. I pulled this trailer back and forth 10 miles to work for 2 years with no accidents, using a standard ball hitch.
Am sure I could get away with a standard hitch setup, but if I can design and build something that might work better, I'm inclined to try!
jesusgatos is offline   Reply With Quote
Old 07-06-2014, 02:54 PM   #14
bikeridermark
Beastly Adventurer
 
Joined: Nov 2008
Location: Southern Ohio
Oddometer: 2,224
Don't you worry about the dogs eating all those exhaust fumes? Most people with dogs use a sidecar.
I remember talking to a guy one time that was trying to design a motorcycle trailer to haul his kids in. I told him that it was illegal to do so. He seemed surprised!
bikeridermark is offline   Reply With Quote
Old 07-06-2014, 04:03 PM   #15
jesusgatos OP
fishing with dynamite
 
jesusgatos's Avatar
 
Joined: Nov 2006
Location: on the road
Oddometer: 2,357
Quote:
Originally Posted by bikeridermark View Post
Don't you worry about the dogs eating all those exhaust fumes?
Yes! I'll have to do something to mitigate that. Probably a combination of a few things, like adding turn-down tips to the exhaust pipes, and making some kind of an enclosure for the dogs that will protect them from the exhaust.

Quote:
Originally Posted by bikeridermark View Post
Most people with dogs use a sidecar.
Yeah, that's always an option but I think a trailer will work better for me.

Quote:
Originally Posted by bikeridermark View Post
I remember talking to a guy one time that was trying to design a motorcycle trailer to haul his kids in. I told him that it was illegal to do so.
Don't have any plans to use it to carry people, but could make a pretty solid argument that this type of trailer could be considered a 5th wheel trailer, and it is legal to transport passengers in a 5th wheel trailer coach in CA.
jesusgatos is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 09:34 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014