help me improve my cargo trailer
 

I made this today, check it out.

The problem is I'm worried about the hitch. The thing is really long, and the wheels are all the way back there, making the midsection of my trailer into a diving board. And with that much flexibility near the front of the trailer, I'm almost positive that it can't carry the weight it's designed to carry (which can range from 100-200 lbs). I was thinking I could maybe cut off a pair of swiveling wheels from a chair and use those as support. It might be noisy, and the wheels may wear down very fast due to the constant contact with cement. I don't really know.

I would like more opinions.

Relocate the wheels to under the load, more to the middle of the cart.

Also, I should say that the wheel set is welded on the frame, and there's really no way for me to move it anywhere. I could take the whole thing apart and put it back together such that the wheel settles in the middle, but that requires me to slice through the aluminum tubing with a hacksaw, and a lot more drilling....

another thing I gotta worry about is the joints by which the tubings are connected. What I did was use a thinner piece of CPVC tubing that slides easily into the aluminum, bolt it onto the aluminum, and so the same to the other side. The PVC sections do make complete contact with the aluminum, even though it slides right in. I don't know if this joint would be adequate.

+1, load 1/3 behind the axle 2/3 ahead , just add a second axle .
maybe use the other one for little wheels to not drag the tail over driveway edges, etc.

an excellent hitch with common parts,
an industrial air tool quick hose connector, [It's what Bike Friday uses..]

we used the connector in its original situation,
running pneumatic powered angle grinders in the shipyard,
other end of the hose connected to the compressor on the Pier.

How much weight are you looking to support? That aluminum tubing and cpvc tubing, especially on a joint, I don't see holding much. Moving the wheels, has already been stated, would certainly help the turning radius of it also.

Well I deliver newspaper. On an average day, that's around 80 lbs. On days when the papers are thick as hell, I think I'll be looking at 180-200 lbs.

I understand why you would think the aluminum tubing would not be able to support 200 lbs. My thinking is that I can maybe fix a vertical pole on the position of the wheel (somewhere near the middle), and use a rope to tie the top end of the pole to the 2 ends of the trailer, like a suspension bridge. The problem with that is that almost all rope is somewhat elastic, and when we're looking at about 60 inches of rope, I'm having serious doubts.

There are trailers I've seen online that are built into a box, or a bridge type. The problem with that is I don't know welding, and I'm guessing the service isn't cheap either. Bolting has its limit as well, considering I don't want my trailer skeleton to look like swiss cheese, full of nuts and bolts.


Also, instead of 1/3 2/3, why not 1/2 1/2? (referring to fietsbob's suggestion)

With a couple of eye bolts,some cable,turnbuckle and a small piece of tubing,you can build a lightweight truss for the sides of the trailer,no welding.That will keep it from bending.

You really should move the wheels forward for that much weight.That will take alot of weight off of the hitch.

You want some weight on the hitch,or when you go over bumps it will want to raise the back wheel of the bike.1/3 forward sounds about right.You could try 50/50,might be a little twitchy.

If you have a straight axle on there,you could use u-bolts/j-bolt to move the axle anywhere along the side frame rails.

Yea , works for suspension bridges..

I just got a Book shelf made .. shelves supported by 2 ladder uprights,
braced against each other with cables [stainless long line leader from the dumpster,
tossed by one of the many Commercial Fishers around here]
crimp tubes to make the loops, and turnbuckles ..

I would also suggest the truss sides.

Another option would be to attach brackets on the bottom of the trailer at both the front and the back. String a braided wire between these two brackets with a turnbuckle at some point within this span. As you torque down the turnbuckle you would apply a pre-load to the bottom of the trailer. This would make the top want to flex upward, which when loaded will flatten out.

here is my newly modified trailer. As you can see, the wheels are now in the middle ish. I also added 2 additional aluminum bars to the 2 sides for both added strength as well as keeping the totes from falling out the side (happened to me twice on the first trial run across town).

what do you think? how much weight should it be able to support? given the weight is equally distributed across the trailer?


sorry about the bad quality. I don't have a camera, and had to use the .3 MP webcam on my laptop. Took me 5 minutes to get the angles right

Looks good, but IMO:
+1 - It'd be a lot stronger with something like that.

That wouldn't flatten out since the whole thing's supported in the middle, not the ends. Needs preload across the top, bearing down on the axle.