harshbarj

I am looking to build a large bicycle trailer, but nearly everything I see online is either very small, or looks like it would fall apart under just it's own weight.

I am needing a 4'x8' (WxL) trailer that can hold around 400-500lbs safely. Lightweight is a must as I have looked into automobile trailers of that size, but they are all over 200lbs. I need to stay at or under 100lbs (so aluminum?). I am not sure if this is something I could build myself, or would have to buy (if it even exists).

Thanks in advance!

Notgrownup

Fiberglass and aluminum... If you can find a set of wheels from a Cavalcdae or Bushtec trailer you can make an axle, you can buy mini airbags from McMaster carr... all the MC trailer axles will be 500 lbs capacity and will be harsh...Biggest thing will be finding someone who can jig it up for you and weld aluminum properly to stay sound. Really isn't hard to build the shell out of fiberglass... Use cardboard, line it with saran wrap that would be stray glued to the cardboard, start with a layer of resin and fabric, i would use the tiger air type or interweaved type fiber glass fabric. Sand the outside, prime, sand, prime sand and spray paint...You will have to be creative... I have seen some pretty cool looking trailers that were hand built like that behing Motorcycles and some were really light....Ptience, measure twice cut once....

harshbarj

So far this is the closest to what I am looking to build, but larger as this is 3x5.. From bloompedal08
https://i13.photobucket.com/albums/a283/Allentown/newhauler.jpg

fietsbob

buy aluminum square tubing then drill out a bunch of holes ,

maybe you can make it so it expands in width as required ..
telescopic cross members .

want to carry sheets of Plywood ?

maybe you can Hire someone that builds stuff to be your builder of it.


Bikes at work bike trailers are long but not wide https://www.bikesatwork.com/bike-trailers

Tim199

I just read about a guy that built a trailer to carry an organ being played in a parade. Seems to be close to your size requirements and says it's about 100 lbs. Are you really sure you need it that wide? Any chance you could put a platform above the wheels of a narrower trailer? A trailer that wide limits where you can go with it.

harshbarj

I would like bigger, but I have to be realistic about what I can haul with the hills I have. If I lived somewhere flat I'd want a 6'x12', perhaps even longer. I don't want to go into what it will be used for yet. Don't want to muddy any suggestions that might come my way, so I'm being secretive .

And I'll be in the street, so i can go anywhere I want. drivers will just have to get use to it.

Thanks for the link btw. I'll look it over this weekend!

wahoonc

The only ready built trailer that I know of that even comes close would be Bikes At Work. Somewhere on here someone built a nice trailer using part of an aluminium extension ladder for the frame. If it was part of an industrial rated (Type 1 or 1A) it would probably work great.

Aaron

Notgrownup

Hey, i saw a guy pulling a canoe or Kayak one time behind his bicycle...Anything can be made...Necessity is the mother...

boberuddy

I used a piece of aluminum ladder for my utility trailer. It is strong, flexes a little, and has been great. Here is a quick picture.


and there is an album of pictures here.
https://cycle.org/gallery/trailer_bike

Notgrownup

That's pretty cool with the ladder....Dayam....

harshbarj

Neat idea, but far too small. For my needs, it has to be 4' at a minimum and even that is going to be a challenge.

boberuddy

Get creative, I was sharing an idea of a neat material to use. Two ladders side by side with wheels underneath is one solution. You have to think outside the box to build something that big and usable.

harshbarj

No problem, I completely understand. I have decided I'll likely do something along the lines of what wahoonc posted. Arc welders are cheap on ebay or even Harbor Freight. That design should be very strong and if I use aluminum should be very light weight. Given a commercial trailer which would be too small is around $800, I will still save even if I buy a nice welder and I'll get just what I need!

If anyone has any more suggestions feel free to post. I am always open to ideas or changes.

Notgrownup

Can you weld Aluminum with ARC? i thought it hat to be TIG... Yep, just googled it...learn sumtin new all de time

Leebo

Surly makes 2 trailers.

turbo1889

You need to look at the trailers designed to be towed behind riding lawnmowers, you can find bigger and especially wider ones in that market, then you just have to rig up a hitch to tow one behind your bike.

Ranko Kohime

There's always wood... It competes with aluminum for both weight and strength, so long as it's put together right. And it's definitely competitive in price, especially when one considers the tools that will and will not be necessary.

That being said, I have a 6'x12' frame sitting in my garage, awaiting funds for completion, that is made of steel. (and I intend to pull it by trike )

harshbarj

I was originally thinking of wood, but figured it would be too weak and heavy to use. It would save me a bit of weight in one way as I do want to place a deck on it, and being wood, it would just be simple to attach a sheet of 4x8 ply. But then would come the problem of wheels and how to attach it to my bicycle. With metal I can see a way of working it, but not with wood.

I have lots of time to plan as I don't need it till spring (around April or May).

harshbarj

I found this post from back in 2008 on another forum ( a forum for apple users, odd something bicycle related would be there). They built almost what I need, just a little short(not a problem really). Sadly they quit updating and there is no more info on the net about what they did in the end.

https://forums.applenova.com/showthread.php?t=33246

Ranko Kohime

On the contrary, wood is very strong. It's no coincidence that the first airplanes were built almost entirely from wood. The trailer I mentioned building is made from 2"x1"X1/16" rectangular tubing, and that stuff is approximately 0.04 lbs. less per linear foot than a 2x4.

Attaching a plywood deck is simple in either method; screw or nail onto a wood frame, use carriage bolts with nuts for steel.

And as for attaching wheels to a wood frame, simply use 4" square steel plates, with milled slots for the axle. (doubled-up junction box covers one finds in the electrical department of hardware stores do nicely for this, in lieu of plate stock)

wahoonc

I have built a couple of trailers out of wood in the past, including one that I towed behind my Honda Civic 1200. In most cases I used 1x2 stock. I if you GLUE and screw the plywood down you get a very lightweight, strong assembly. The single biggest issue with wood compared to metal is durability, however properly protected from the weather and with reasonable maintenance they will last a long time.

For starters check out The Mother Earth News bicycle trailer.

Aaron

harshbarj

I tried weighing a chunk of 2x4 I have here and figuring it as an average weight, the frame would weigh about 80lbs.. Plus screws and the wheels(x4). So perhaps 85lbs. A little heavier than I wanted, but far less than I feared. Perhaps if I used a lighter wood for the interior supports I could get that under 70 as most of the weight will be supported by the main beams anyway.

Tim199

Short version: 2x4's are made out of light strong wood.

Construction lumber (2x4 2x6 etc) is typically made out of Spruce, Pine, or Fir, often abbreviated as SPF, or "whitewood" which can be just about anything cheap including SPF. SPF are rather high on the strength to weight ratios as it is and you're not likely to find an easy source of lighter wood as strong. If you have access to good woodworking equipment you might have luck thinning down a 2x4 or 2x3 to the size you need but still get the required strength. You could also go with the 3/4" thick whitewood sanded boards the big box stores sell to save on some weight in places, but be careful you get enough strength. It can be significantly more expensive that way depending on the dimensions of the boards you choose.

Getting the strength you need and having it as light as possible is going to come down to your design skills in the end.

fietsbob

Out side of the Box as it were,
... might consider a folding wing set-up with some small wheels,
to support the wide load at the edges


or if its a sheet of Plywood, fabricate a set of clamp on wheels, and the towing connection ..
to use the load itself as the trailer frame .

Turbo231

Can I be that guy who mentions to make sure you have enough brake on your bike to stop your trailer and what's on your trailer?