Go Back  Bike Forums > Bike Forums > Utility Cycling
Reload this Page >

I have a plan for a NEW, cheap trailer ...

Utility Cycling Want to haul groceries, beer, maybe even your kids? You don't have to live car free to put your bike to use as a workhorse. Here's the place to share and learn about the bicycle as a utility vehicle.

I have a plan for a NEW, cheap trailer ...

Reply

Old 08-22-07, 04:49 PM
  #1  
Andronicus
Junior Member
Thread Starter
 
Join Date: Jul 2007
Posts: 14

Bikes: More than a few. Less than a dozen.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I have a plan for a NEW, cheap trailer ...

Northern Tool has a hand truck for only $20. http://www.northerntool.com/webapp/w...70_47425_47425
This is cheaper than I could find parts to build my own trailer. I ordered one. It's going to lay horizontal behind the bike with a tow bar bent from a piece of electrical conduit attached to the truck with a couple of steel hose clamps. The hitch is what I couldn't quite figure out until I found this: http://www.wikihow.com/Image:TrailerB3.jpg_four.jpg
I figure my total cost will be well under $50 bucks, even after I mount a board and a storage box!

Last edited by Andronicus; 08-27-07 at 06:31 PM.
Andronicus is offline  
Reply With Quote
Old 08-22-07, 05:12 PM
  #2  
JunkyardWarrior
Senior Member
 
Join Date: Aug 2007
Location: st. pete, fla
Posts: 278

Bikes: royce union (univega) full susp mtb, work trike, assorted extra bikes

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
cool.......post some pics when its done
JunkyardWarrior is offline  
Reply With Quote
Old 08-23-07, 01:23 PM
  #3  
Nightshade
Humvee of bikes =Worksman
 
Nightshade's Avatar
 
Join Date: May 2004
Posts: 5,362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Your idea is a good one but there is an unseen flaw........
The dolly has wheels that are to far back for the hitch
you noted. The turn arch for the dolly may create enough
twisting leverage that either the hitch plate or axle stud will
fail.

All would be much better if the wheels were more forward
more towards dolly center for your idea.

P.S. with the trailer axle that far back from the hitch point it'll
"take a forty acre field to turn that rig around". Think semi-trucks.
__________________
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.

Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
Nightshade is offline  
Reply With Quote
Old 08-23-07, 05:19 PM
  #4  
Andronicus
Junior Member
Thread Starter
 
Join Date: Jul 2007
Posts: 14

Bikes: More than a few. Less than a dozen.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've seen some commercially-sold trailers with the wheels in the rear too.
http://www.bikesatwork.com/hauling-cargo-by-bike/
Any hitch issues can be tweaked and solved. I think it's gonna be
just fine. Hey, if it really sucks, I'll still have a perfectly-good hand truck anyhow!

Last edited by Andronicus; 08-23-07 at 05:33 PM.
Andronicus is offline  
Reply With Quote
Old 08-24-07, 01:27 PM
  #5  
Nightshade
Humvee of bikes =Worksman
 
Nightshade's Avatar
 
Join Date: May 2004
Posts: 5,362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Originally Posted by Andronicus View Post
I've seen some commercially-sold trailers with the wheels in the rear too.
http://www.bikesatwork.com/hauling-cargo-by-bike/
Any hitch issues can be tweaked and solved. I think it's gonna be
just fine. Hey, if it really sucks, I'll still have a perfectly-good hand truck anyhow!
You CAN make this idea work "if" you will consider going to a seat post hitch using a strip of tire
sidewall to allow the twisting while towing that this trailer will give. I dare you to break the
tire strip 'cause I've used one for 35 yrs on my trailer.

Best of luck.
__________________
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.

Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
Nightshade is offline  
Reply With Quote
Old 08-24-07, 05:04 PM
  #6  
Andronicus
Junior Member
Thread Starter
 
Join Date: Jul 2007
Posts: 14

Bikes: More than a few. Less than a dozen.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Seat post hitch with a strip of tire sidewall. I'm game. How do you rig it?
Ahhh, found it, thanks! http://www.motherearthnews.com/DIY/1...e-Trailer.aspx

Last edited by Andronicus; 08-24-07 at 06:44 PM.
Andronicus is offline  
Reply With Quote
Old 08-24-07, 11:54 PM
  #7  
Bushman
Grumbly Goat
 
Bushman's Avatar
 
Join Date: Jul 2007
Posts: 895

Bikes: bicycles with round wheels

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Originally Posted by Tightwad View Post
You CAN make this idea work "if" you will consider going to a seat post hitch using a strip of tire
sidewall to allow the twisting while towing that this trailer will give. I dare you to break the
tire strip 'cause I've used one for 35 yrs on my trailer.

Best of luck.

+1 for tire strip hitches!!
Bushman is offline  
Reply With Quote
Old 08-25-07, 01:22 AM
  #8  
Cyclaholic
CRIKEY!!!!!!!
 
Cyclaholic's Avatar
 
Join Date: May 2005
Location: Sydney, Australia
Posts: 4,269

Bikes: several

Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 684 Post(s)
Originally Posted by Andronicus View Post
Northern Tool has a hand truck for only $20. http://www.northerntool.com/webapp/w...70_47425_47425
This is cheaper than I could find parts to build myown trailer. I ordered one. It's going to lay horizontal behind the bike with a tow bar bent from a piece
of electrical conduit attached to the truck with a couple of steel hose clamps. The hitch is what I couldn't quite figure out until I found this: http://www.wikihow.com/Image:TrailerB3.jpg_four.jpg
I figure my total cost will be well under $50 bucks, even after I mount a board and a storage box!
You're going to have some pretty serious stability issues with this design, but it seems that your mind is made up to at least try, so..... good luck with it. All I can advise is to be extra carefull when you get it out for a road test.
__________________
May the m(dv/dt) be with you.
Cyclaholic is offline  
Reply With Quote
Old 08-25-07, 09:28 AM
  #9  
Andronicus
Junior Member
Thread Starter
 
Join Date: Jul 2007
Posts: 14

Bikes: More than a few. Less than a dozen.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Please expound and educate me. I don't pretend to know what I'm doing here; I'm a hack with a penchant for cheap ... . What serious stability issues?
Andronicus is offline  
Reply With Quote
Old 08-25-07, 09:49 AM
  #10  
Nightshade
Humvee of bikes =Worksman
 
Nightshade's Avatar
 
Join Date: May 2004
Posts: 5,362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Originally Posted by Andronicus View Post
Please expound and educate me. I don't pretend to know what I'm doing here; I'm a hack with a penchant for cheap ... . What serious stability issues?

it comes back the rearward placment of the trailer wheels. Even with a tire strip hitch this
design will be narrow and always out of balance.
__________________
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.

Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
Nightshade is offline  
Reply With Quote
Old 08-25-07, 11:54 AM
  #11  
sumguy
Senior Member
 
sumguy's Avatar
 
Join Date: Aug 2007
Location: nw ohio
Posts: 563

Bikes: 08 Novara Safari; 06 Schwinn Super Sport DBX

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Anybody ever modify a deer cart?


sumguy is offline  
Reply With Quote
Old 08-25-07, 04:11 PM
  #12  
Nightshade
Humvee of bikes =Worksman
 
Nightshade's Avatar
 
Join Date: May 2004
Posts: 5,362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Deer trailers have a center of gravity that is to high for cycling.
NOT a good idea. Sorry.
__________________
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.

Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
Nightshade is offline  
Reply With Quote
Old 08-26-07, 09:23 PM
  #13  
cerewa
put our Heads Together
 
cerewa's Avatar
 
Join Date: Jun 2003
Location: southeast pennsylvania
Posts: 3,155

Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I'm not really convinced either of those designs is all that bad.

The hand cart will have stability issues because of the large amount of stress it will put on the trailer tongue, and the small wheels (which will not soak up bumps as well as 20 to 26 inch wheels). The deer cart will be problematic if you load it so that it exerts upward force on your bike's rear wheel by loading the majority of the weight behind the cart's wheels. (this would be true if you loaded your stuff onto the horizontal portion of the deer cart.) But the height of the center of gravity of your stuff on the deer cart wouldn't be so bad provided you loaded the cart down with half the stuff further forward than the wheel axles.

For example, the only way to carry a wooden futon-frame on my trailer is to load the entire thing on top, which puts the bottom of the load at about 22 inches above the ground (as in, above the tops of the 20" wheels). The center-of-gravity of the trailer plus the load was probably about 18" above the ground and to achieve that with the deer cart you'd have to pile stuff pretty high on it. Doing so would keep the weight fairly stable on the cart as long as you took all of your turns at a reasonalbe speed, avoiding anything that would make you lean your bike at an angle past 40 degrees or so.
cerewa is offline  
Reply With Quote
Old 08-26-07, 09:36 PM
  #14  
Allen
Senior Member
 
Join Date: Sep 2005
Posts: 4,757
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Originally Posted by sumguy View Post
Anybody ever modify a deer cart?



Originally Posted by Tightwad View Post
Deer trailers have a center of gravity that is to high for cycling.
NOT a good idea. Sorry.

That's the trailer in his link. That's about as low of a center of gravity as one gets.
Allen is offline  
Reply With Quote
Old 08-26-07, 09:40 PM
  #15  
Cyclaholic
CRIKEY!!!!!!!
 
Cyclaholic's Avatar
 
Join Date: May 2005
Location: Sydney, Australia
Posts: 4,269

Bikes: several

Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 684 Post(s)
Originally Posted by Andronicus View Post
Please expound and educate me. I don't pretend to know what I'm doing here; I'm a hack with a penchant for cheap ... . What serious stability issues?
I totally resemble that remark

Here's a few of rules of thumb I've developed through experimentation over the years that work for me....

1. Look at the point where the trailer hitches to the bike, and the points at which the trailer's wheels touch the ground. They form a triangle, right? OK, you want to keep the sides of the triangle reasonably close to being the same length. If the side of the triangle that lies along the trailer's axle line is the base then I would keep the height of the triangle (i.e. the distance from the trailer axle line to the hitch) to a maximum of about 1.5 to 2 times the base.

2. You want the center of gravity of the trailer (especially when loaded) to fall pretty much on the axle line of the trailer wheels so that there's very little upwards or downwards force at the hitch. that means that you want the wheels pretty close to the middle of the trailer, not all the way back down the end.

3. You want to make the trailer as low and as wide as reasonably possible so as to keep the center of gravity (when loaded) as low as possible, the lower it is the more laterally stable it is. I try to stay below 3:1 width to height ratio.

Looking at your proposed design (without doing a mathematical analysis) I get the impression that the 3 rules are violated sufficiently as to create a trailer that won't handle too well with any reasonable load. Of course this is just my opinion based on past experience and I could very well be completely wrong, which is why I'm interested to see how it turns out.

The one big variable here is just how much stability do you want? I often take sweeping bends at up to 20mph with 50lb on the trailer on less than perfect surfaces and I can hardly tell its there. I occasionally even take a short cut home from the grocery store down a stretch of singletrack. That requires a nice stable design and a good hitch with no slop. You may be perfectly happy with something less than that.
__________________
May the m(dv/dt) be with you.
Cyclaholic is offline  
Reply With Quote
Old 08-27-07, 01:24 AM
  #16  
Bushman
Grumbly Goat
 
Bushman's Avatar
 
Join Date: Jul 2007
Posts: 895

Bikes: bicycles with round wheels

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Deer carts work great, excellent balance and center of gravity. same with small ATV carts. As for the tire placement near the rear it is NOT an issue. There is about a dozen bike trailers commercially available with the tires at the VERY rear of the trailer. Some of these trailers are over 10 - 15 long and routinely haul heavy goods.

Prime example is the link someone posted above,.
Bushman is offline  
Reply With Quote
Old 08-27-07, 09:21 AM
  #17  
JunkyardWarrior
Senior Member
 
Join Date: Aug 2007
Location: st. pete, fla
Posts: 278

Bikes: royce union (univega) full susp mtb, work trike, assorted extra bikes

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
my vote is for the deer cart.......if you mount it to the seatpost the same position it is in that pic then it should work fine........all the wieght can be stacked twards the front on the angled part and will be on the mount.............so maybe double up that tire wall strip

plus the deer cart looks lighter.........and the bigger wheels
JunkyardWarrior is offline  
Reply With Quote
Old 08-27-07, 09:24 AM
  #18  
JunkyardWarrior
Senior Member
 
Join Date: Aug 2007
Location: st. pete, fla
Posts: 278

Bikes: royce union (univega) full susp mtb, work trike, assorted extra bikes

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
you could also (mounting it in that position) cage up the back of it with pipes ......just go straight up from the back and then to the front.........old metal animal cages work good too.............i have one on my trike
JunkyardWarrior is offline  
Reply With Quote
Old 08-27-07, 09:25 AM
  #19  
JunkyardWarrior
Senior Member
 
Join Date: Aug 2007
Location: st. pete, fla
Posts: 278

Bikes: royce union (univega) full susp mtb, work trike, assorted extra bikes

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
oh yea........remove the top of the cage............dont try to use the door..........lol
JunkyardWarrior is offline  
Reply With Quote
Old 08-27-07, 09:36 AM
  #20  
rhm
multimodal commuter
 
rhm's Avatar
 
Join Date: Nov 2006
Location: NJ, NYC, LI
Posts: 18,595

Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...

Mentioned: 370 Post(s)
Tagged: 0 Thread(s)
Quoted: 1317 Post(s)
Andronicus,

My speculation is that the wheels of your hand truck will be too close together for a stable bike trailer and this will make it tippy; and that the wheels at the extreme back will put undue load on the hitch. On the other hand, I like the 10" pneumatic tires; you can change the axle configuration to a longer axle farther forward, you may have something that works just fine. How well your trailer suits your needs will probably depend mostly on what your needs are.

My experience comes from putting a canoe on a stripped down jogging stroller and towing it behind my bike. For a hitch I just chain the end of the canoe to the seat. It's primitive, but it works. Anyway, what I've learned is: when the wheels are too far back, there's too much weight on the hitch, which makes the bike handle badly in one way, but when the wheels are too far forward, i.e. near the balance point, the bike handles badly in a different way. It's pretty scary when there isn't enough weight on the hitch and the canoe starts swinging side to side! So the trick is to find a happy medium. Even so, hitting a minor dip in the road with one wheel threatens to tip the whole thing over; I've had one wheel come off the ground more than once, scaring the **** out of me. The problem with my design is the narrow wheelbase. It also has a fairly high center of gravity, which compounds the stability problem, but I need the canoe to be pretty far off the ground so the end doesn't drag.

Good luck! I look forward to hearing how it works out.
rhm is offline  
Reply With Quote
Old 08-27-07, 09:40 AM
  #21  
sumguy
Senior Member
 
sumguy's Avatar
 
Join Date: Aug 2007
Location: nw ohio
Posts: 563

Bikes: 08 Novara Safari; 06 Schwinn Super Sport DBX

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
deer cart is 33.5lbs, 16in solid wheels, 19in wide load area. seems like you could mount it high or low depending how you want to load it. seat post mount has the vertical section coming up toward seat. low mount has vertical section going away from bike.
sumguy is offline  
Reply With Quote
Old 08-27-07, 06:15 PM
  #22  
Andronicus
Junior Member
Thread Starter
 
Join Date: Jul 2007
Posts: 14

Bikes: More than a few. Less than a dozen.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by Cyclaholic View Post
I totally resemble that remark

Here's a few of rules of thumb I've developed through experimentation over the years that work for me....

1. Look at the point where the trailer hitches to the bike, and the points at which the trailer's wheels touch the ground. They form a triangle, right? OK, you want to keep the sides of the triangle reasonably close to being the same length. If the side of the triangle that lies along the trailer's axle line is the base then I would keep the height of the triangle (i.e. the distance from the trailer axle line to the hitch) to a maximum of about 1.5 to 2 times the base.

2. You want the center of gravity of the trailer (especially when loaded) to fall pretty much on the axle line of the trailer wheels so that there's very little upwards or downwards force at the hitch. that means that you want the wheels pretty close to the middle of the trailer, not all the way back down the end.

3. You want to make the trailer as low and as wide as reasonably possible so as to keep the center of gravity (when loaded) as low as possible, the lower it is the more laterally stable it is. I try to stay below 3:1 width to height ratio.

Looking at your proposed design (without doing a mathematical analysis) I get the impression that the 3 rules are violated sufficiently as to create a trailer that won't handle too well with any reasonable load. Of course this is just my opinion based on past experience and I could very well be completely wrong, which is why I'm interested to see how it turns out.

The one big variable here is just how much stability do you want? I often take sweeping bends at up to 20mph with 50lb on the trailer on less than perfect surfaces and I can hardly tell its there. I occasionally even take a short cut home from the grocery store down a stretch of singletrack. That requires a nice stable design and a good hitch with no slop. You may be perfectly happy with something less than that.
Cart came in today minus the wheels. Hope the wheels show tomorrow (damn UPS).
Heeding your advice, here's the plan:

Gonna cut off the top half of the cart on one side, and use the remaining side as my trailer-hitch
arm instead of adding conduit piping to make an arm. This will reduce the length of the deal by about
a third, and will use an integral piece of the cart for an attachment arm. (While leaving enough space for
a cargo box.)
Gonna cut off the wheels at the base of the cart and re-weld them about 10" up from the bottom.
This will put the wheels roughly in the center of the trailer instead of at the bottom.
The width I can't do anything about without getting a longer axle, and I don't really want to since I'd
still like to squeeze between cars.
I'm gonna go with a strip of tire sidewall to attach the deal to the bike; I'm trying to keep it really simple and really cheap. So far I'm into it all of 33 bucks worth ...
Thanks much for your help and input!

Last edited by Andronicus; 08-27-07 at 06:27 PM.
Andronicus is offline  
Reply With Quote
Old 09-18-07, 09:54 PM
  #23  
StephenH
Uber Goober
 
StephenH's Avatar
 
Join Date: Sep 2007
Location: Dallas area, Texas
Posts: 11,593
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 132 Post(s)
A while back, I was using a little handcart (one of those fold-up models) to move a couple of boxes across a parking lot. It had a very annoying tendency to rock back and forth until it actually tipped- and this when being towed. So I can see that being a problem with a trailer.

Also, on the furniture dollies, they are made for moderately heavy loads at slow speeds. So they're heavy may not have ball bearings, and no suspension. The deer cart sounds more promising. I used to see adds in Popular Mechanics for oversized handcarts using bicycle-type wheels that might be adaptable (they were sold as an alternative to a wheel barrow.)
StephenH is offline  
Reply With Quote
Old 11-26-07, 10:01 PM
  #24  
mvillan
Senior Member
 
mvillan's Avatar
 
Join Date: Mar 2006
Location: Northern California
Posts: 166

Bikes: Continuously changing assortment. Do Two Unicycles make one bike?

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
just picked up a welding cart at harbor freight. $50 in store and has 20" wheels... that wheels aren't centered put its pretty darn close to being a bike cart on its on.. all I have to do is make a hitch and tongue shouldn't cost more than $10 usual conduit and air hose fittings

here is a link to the cart

http://www.harborfreight.com/cpi/cta...emnumber=43615

and I flips the bolt on handle bar
mvillan is offline  
Reply With Quote
Old 11-26-07, 11:06 PM
  #25  
KnhoJ
Mister Goody Two Shoes
 
KnhoJ's Avatar
 
Join Date: May 2006
Posts: 417
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by AllenG View Post
That's the trailer in his link. That's about as low of a center of gravity as one gets.
And $60, too. That ain't bad! Folds up... Kind of tempting, really... Maybe with some lawn chair webbing, it could make for a comfy trailer...
KnhoJ is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service