Harbor Freight Folding Trailer

Yeah, Yeah, I know us cool guys never trailer a bike, but I have to figure out a way to get two trail bikes to a trail. I was hoping to build some form of two bike hitch hauler, but load was going to be just a bit more than I was comfortable with. Having a trailer that will carry a big street bike isn't the worst thing either. I haven't bought a trailer up until now, mainly because I have no where to store it. So here's my compromise, the 1195 lb. Capacity 48 in. x 96 in. Heavy Duty Folding Trailer Haul-Master - item #90154  to get a folding trailer from Harbor Freight. I got it on sale for like $250, but that was not the end of my spending by a long shot. If it wasn't for the compromise of the folding trailer, I would have been better off to buy a small ready to go trailer that sits out in front of Northern Tool.

This project has been quite a challenge from start to finish with several reworks and compromises to get it to the way I wanted it. I won't bore you with all my not good ideas and screw-ups, just notes about things I ran into and what works.

First of all, be ready to spend a whole weekend getting the frame built up and wired. A good friend to help is always a good thing.

Notes on the initial build. The fasteners heads are metric, but the threads are SAE. Go figure. The ball coupler is 1 7/8 inch not 2 inch; so if you only own a 2 inch ball then you need to buy a 2 inch coupler or a set-up with 1 7/8 inch ball.


After I got the trailer frame built, I was not impressed with the way the bolts held each half of the trailer frame square. So measure each half corner to corner and square it up. Then I had a friend(thanks Scott) weld gussets in each corner. I know the plywood deck would have helped keep it square, but I wanted the gussets. I shot a little paint on those to keep rust at bay a bit.


The next thing I found very lacking was the tiny casters that it is supposed to roll on when folded. I bought this thing to fold and store so those are kind of important. The included casters barely work on a decent concrete floor. Forget about using those by yourself in the yard. This mod will require the stake pockets to be moved, but that's minor and I'm not building up a utility trailer, yet.


I knew this was an issue before I brought the thing home, so I bought bigger full swivel casters at Harbor Freight. Stock casters below left. The big full swivel casters were welded to heavier angle iron(thanks again Scott) and mounted below right.


Don't wire it with all the wire nuts and scotch locks that come with it. Solder and shrink wrap the connections. I also used some loom and drilled a hole to clean up the taillights a bit.


Wiring, oh the @@##!! wiring. You have to have some slack in the wiring for it fold and you have to keep the slack from getting cut when you're folding it and/or running down the road.  I cut and repaired the wires more times than I care to admit while figuring this out. This is the final routing that seems to work. Stick-on zip-tie holders that keep it tight to the rails and loose away from the bolts that hold it away from the leaf spring bolts.


I chose to get a trailer jack. That's another $25 add-on.You would think that HF sells the 1000 pound model to fit the 1000 pound trailer, but no. The bolts that come with it are way too long. Off to ACE hardware; this is when I really noticed that the metric marked bolts have SAE threads.


This is another dumb feature of a folding trailer. You're suppose to use a carriage bolt and nut through this hole to keep it from folding while in use and then take it out when you fold it. What a pain to get on your knees with a ratchet every time you use it and storage it. So get a 3/8 inch hitch pin with a wire lock. Easy peasy.


Now on to the deck. You see this page in the instruction manual. It's basically worthless.  You need a full sheet of 3/4 inch plywood and know that 3/4 inch from the edge of the board will put you in the middle of the rail. Here's the stupidest parts of this drawing, I couldn't find any 3/8 inch cross heads so I used 3/8 in carriage bolts. If you put those in the locations of the existing holes in the rails of both halves, then the heads will hit and the trailer won't fold up nice and tight. So you'll need to offset and even counterbore some of the bolt heads.


The next thing required and unmentioned on the drawing is the inside corners of each half need to be cut just a bit in order for the pieces to actually fold.


Something I didn't like about adding a deck was that the outside rails stand proud of the cross rails. That stresses and strains the board more than I care for. I bought some 1/8 inch thick metal strips to fill that gap and more red spray paint.


Figuring out the tie downs was more of a challenge than it should have been. I need something that would not interfere with the folding of the trailer. I couldn't find anything that would mount on the outside rails of the trailer and work for my two little bikes or one big bike in the middle plan.

Then I figured it out:  flush mount rings. I got these at Northern Tool. There's a ring only version and ring with metal backer version.



Wheel chocks were pretty easy. I got an eBay deal on a 3 inch Pingel removable chock for the Trail 90 and the Northern Tool 5 1/2 inch for the Trail 70 or big bike. The price difference between the Pingel and Chinese is obvious in the fit and finish. I bought the Chinese mainly because it was local and I was impatient. I also bought a Pit Posse spare mounting kit, mainly because it looked the same as the Northern Tool set. The wing bolts/t-nuts with the Northern Tool are metric. So keep that in mind when you buy hardware for your alternative location.



This is the configuration I came up with. A spot for three chocks up front. Three tie downs on the front rail. Those won't need a metal backing plate. Three tie down near the back of the front half. The outside set will be bolted through to the rail and the middle will have a backing plate. Two tie downs a bit back from the front of the back half with backer plates.

The little bikes will use the outside chock positions and tie down to the middle and front corners and middle and outside tie downs. A big bike will fit on the middle chock, tied to the front corners and the farthest back tie downs.


Lay out the front tie down locations. The metal backing plate makes a great pattern.


Drill the little holes and use a plunge router on the middle hole. A little more fitting and it's good to go. The front tie downs are far enough forward that just surface mounting does not affect the folding of the trailer. The very corners of the front rail have bolt holes, but the rest need to be drilled.


The three middle tie downs came with a surprise or two. They could not be surface mounted without messing with the folding of the trailer. So I used my plunge router to make 1/4 inch deep recess for them. I don't think the strength will be compromised much, given the outside two are bolted through the frame rails and the middle one will have a metal backing plate.The other surprise was that the recess of the middle tie down hit the frame rail. So I chain drilled what was in the way and then cleaned up the edge with a stone wheel on a die grinder. A little more paint and everything fits like a glove.


The two tie downs in the back half needed recesses as well, but luckily no chain drilling. Here's an example of a counterbored bolt head, too. Notice how rough my boards look. I had bought exterior grade plywood, but this is ridiculous. They had only been outside for like two weeks in the weather. I have been contemplating some form of sealant or paint, something like truck bed liner.


I decided to add a small toolbox and spare tire. The toolbox was another compromise. A big tongue box is just more weight to try and fold up, but something to store spare hardware and tie downs is needed. I bought a simple 30 inch handbox for like $40. 24 inch boxes are a little less and a little more available, but 30 spans the whole "A" of the tongue. I didn't like the stand off spare tire style holder from Harbor Frieght, because I don't like it sticking out when the trailer is folded up. I bought a Dorman 41068 spare tire hold down from Pep Boys. The J-Bolt was too long to work, so I used a 5/16 carriage bolt through the cross piece of the "A" instead. The plate and wing nut were worth the $5 though.


All together and looking good. I will run a heavy zip tie from the trailer through the wheel spokes to keep it from turning its way off going down the road.



Here's my basic full mock up before coating the deck. After talking to people and looking at some examples I decided that Herculiner was the way to go.


I decided to spray paint all the holes and recesses that I didn't want to build up with heavy coating.


Herculinered out. Some notes on this stuff. Get a paint stirrer for a power drill. Wear gloves and clothes that you don't care about ruining. I didn't quite get both sides of both panels covered with the gallon kit, but I could have stretched it farther with better mixing. I used spray paint and plasti-dip on one of the undersides.


I was waiting to get it all together before I would install a method to keep the halves together when folded. I think it's pretty lame that this trailer doesn't come with something to lock it together folded. I think instructions say use rope, but that's not a decent option once the deck is on. After bringing home a half dozed hasps and latches, I finally found an option that was the correct length to work. It's a safety gate hook.


I thought the catch was spring loaded, but it's gravity that holds it together. That meant I had to add it to the very back rail instead of the front rail. The front would have been a safer spot when not in use. This worked out very nice and holds things together well.


I bought another staple, and mounted it, so that the safety hook doesn't hook someone that's walking around the rear of the trailer.



This is how it stores. I need to get something that locks it down better, so a thief will have to work just a little to get it.