Bike Trailer -- tough and light

Instructions on how to build a tough and light bicycle trailer out of standard light gauge angle iron found at the hardware store. This design is tough, relatively light, easy to build and easy to customize.

Step 1 Collect Tools

Tools required for this job include --

Hammer
Chisel
Hack saw
Adjustable wrench (two)
Ratchet with 5/16 socket
Pliers
Drill with phillips bit
Tape measure
Sharpie
Combination square

If you have a circular saw, it may be easier than using the hammer and chisel. Eventually I got sick of using the hack saw and borrowed a friend's angle grinder with a cutting disk.

Comments

[drbill]

Can You Say Erector Set ?

I wonder if this can be put into a box and marketed . . . . . .

[parrster]

Brilliant. I've been looking to build something like this for my son to help with his paper run. I like this design for its simplicity and ease of construction. Great job.

[Databanks]

Wow, such a cheap but effective way to make a coupler. And I've no shortage of castors that have worn out their rubber wheel hanging around...
Nice idea and thanks for sharing

[rabid_engineer]

Most interesting! Congratulations on a sturdy and (in its neatness) visually appealing design. I wonder, have you put it to extended use yet? I suppose not, looking at the date of publication. The reason for my asking is that I think nylon washers as bushings might wear out quickly, since it is a threaded rod. Perhaps a flush one would have been better, but then, you have the trouble of holding the axle and wheels in place, of course.

[arcraven]

Good point. A friend recommended filling the threads with "liquid metal" (never heard of it before) and filing it smooth so that the axle doesn't wear down at those points where it touches other parts.

[freewheel]

Your friend is probably talking about JB Weld. It's available at most auto-repair shops like Autozone. Great project!

[Mr. H.S. Thompson]

 WOW!!!!!

this is beautifull, rabid_engineer said it perfectly, "in it's neatness visually appealing"

I really wish I hadn't sold my bike, if I still had it I would go out and do this!

[godspiral]

where/what are the wheels from?

[arcraven]

I bought the wheels from Northern Tool. They're about 20" diameter and have built in bearings. Here's Northern Tool website --

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_1030_1030

[weblar]

I like your trailer design a lot - it does look strong and light!!

I agree with the posts regarding the "swivel-ability" of your attachment point. I've designed and built a number of bike trailers over the years, and have accomplished that "swivel-ability" by moving the attachment point for the trailer to just behind the rear wheel/tire of the bicycle using 3/4 X 3/4 square steel tubing that is also available from hardware stores and then using a second caster to allow the full range of trailer tongue motion: up and down, side to side, and rotational.

Though the current trailer I designed makes use of a push/pull golf cart that I purchased off CraigsList for the low price of $5 and a plastic tub, the trailer attachment design I suggest has held up very well all this summer over some very extended bicycle rides (one over 225 miles).

I also replaced the cheap bearingless wheels that came on the golf cart with sleeve-bearing wheels that I bought from Northern Tools - a great place to shop for wheels for projects like these.

You can see the trailer coupler I describe also posted on Instructables at http://www.instructables.com/id/Building-a-strong-flexible-bicycle-trailer-coupler/

[macrumpton]

Do you think rather than cut out a notch out of the tongue if you did a single cut and bent one side up and the other down you could overlap them so you could put a bolt through both sides?

[arcraven]

Yes, I did try this when building. The angle iron is light gauge, but not light enough to do that easily (although if you cut it craftily enough, I'm sure its possible). It was easier for me to cut the notch and reinforce it with the bracing.

[rowerwet]

why not use a second caster to make the second hinge axis, connect them at the axle bolt holes (one axle bolt through all 4 axle hole ears) so that one swivel plate was 90 degrees to the other. (one for pitch and one for roll) would make the tounge connection a little different, but no major changes. great design!

[ericdncn67]

turning with the second attachment would stress the rear of the bike.

[rowerwet]

the axle bolt would be the joint for bike CL to trailer CL angle changes, the swivel plate attached to the frame would be the joint for bike to trailer pitch changes, and the swivel plate attached to the trailer arm would be the joint for the bike banking into turns while the trailer stayed flat.

[arcraven]

I'm experimenting with this right now and will post my pics/opinions. At first glance, seems it could work.

[arcraven]

Seriously considering doing this. Thanks.

[macrumpton]

Instead of mounting the piece of wood on the frame to mount the axle on wouldn't it be easier to just drill two axle size holes in the angle iron and mount the axle directly on the frame? Then you could eliminate the wood, brackets and mounting screws. It would even lower the center of gravity a couple of inches.

[ericdncn67]

light angle isn't strong enough for the 100lb limit. The wood in the middle of the platform gives it strength(making up for light angle).

[arcraven]

Exactly. Without the 2x6, the axle bends under heavy load, causing the wheels to splay out. The wood also adds rigidity to the frame so it doesn't rack.

[brizzx32]

Hello good Instructable, just had a question did you just use a regular bike wheel or what kind did you use and where did you get it?

[arcraven]

The tires are for garden carts. I bought them at Northern Tool. Here's the link --
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_1030_1030

[fractionalphysicist]

One problem with this design that should be fairly easy to rectify. there isn't a rotational degree of freedom about the in-plane axis; i.e. you cannot lean your bike in a turn, as required for any substantial amount of momentum. Other than that a great build. Just be careful around those bends.

[allen]

What I did when I needed a light-duty universal joint was to take two fairly heavy threaded eye-bolts, get one red-hot with a torch so I could open it up and put the opened end through the other eye and closed it up again. Worked just fine.

[arcraven]

Yes, that is a problem I'm aware of. There's been enough play in the coupler/receive for this not to be a big problem. However, I haven't had to pedal "out of the saddle" yet with the trailer (for going over hill or sprinting). I'm interested in anyone's solution, though I prefer not to have to completely redesign the connection yet again.

[kklaw]

How about a heavy duty spring? The connection on my store-bought trailer that our kid sits in has a simple rigid post-and-hole connection but a section of the tow bar is actually a heavy spring. It makes turning quite easy and provides much needed flexibility between bike and trailer. Just a thought.

[Msaggese]

What about a hinge type of setup between the caster and the bike? The hinge would be at a right angle when the bike is upright, with the caster below it, so that in a turn the hinge could go up or down depending on the direction of the lean. I'm sure someone would be able to figure it out

[arcraven]

Good idea -- sketch attached, comments welcome. (no, I do not work for Perkins + Will) I'm wondering if there will be too much back and forth movement in such a design.

[drbill]

This is a good idea for turning with a lean.

[fractionalphysicist]

You might catch the spokes in the rear wheel. What about another caster in line with the support arm and 90 degrees "out" from the 1st caster.

[Msaggese]

I was thinking more along the lines of the hinge being horizontal, or bent at a 90 degree angle, so that when leaning the bike right, the hinge will open downward, and when leaning left, it would close upward. This might avoid the problem of the spokes catching, but i'm not entirely sure. i'm just thinking conceptually

[Msaggese]

Exactly, That was the only problem that i could see with it. It might work

[thepelton]

I was about to suggest some sort of universal joint near the point of attachment to the bike, myself. If you just have it attached with a bolt, the tires would drag and screech on a sharp turn, and wear out too fast.

[ksteinhoff]

Here's a guy I ran into a few years back who biked all over the country with his homemade trailer. Neither he nor the trailer were light

[goodgnus]

Reminds me of an erector set! Any bike trailer is a good bike trailer as far as I'm concerned. Props!

[Iconoclastic Technocrat]

Very nice instructable! Nice attention to detail. I like the way you made the angle on the trailer tongue with L stock metal. It's hard to find recycled round tube with the angle you need. The name of the pin you mentioned you forgot is a clevis pin. I also like the use of that type of wheel -do you have a link for your source?

[arcraven]

Thanks! I used Northern Tool to source the wheels. Links to home site and to 20 inch wheel.

http://www.northerntool.com/
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_1030_1030

[Yerboogieman]

Those "Adjustable Wrenches" are called Crescent wrenches.

[superpenguin]

Hey, this is great! I think I'll be needing a bike trailer soon, and this looks should be hugely helpful. The use of the caster wheel for the receiver is very innovative and a great idea.

[omnibot]

Best bike-trailer yet!