My Mini Trailer

[Simon Thomas]

I have built my simple buggy. Now I intend to build a mini trailer. Just a simple trailer to transport stuffs like mini tiller and pump. I think this idea is pretty practical when living in remote area.

I intend to design a mini trailer that is pulled by a motorbike. So it must be simple, light and not get broken when travel through the terrain area. I wish to design something that can withstand the weight of around 200kg. I want to make this build as cheap and simple by using all the available stuffs that I can easily get from shop and scrap metal at my area.

This idea was inspired when I had a chit chat with an old man living in the remote area and he hardly find a simple mechanical device to assist him in his farm.

 

[Simon Thomas]

These are the stuffs that I wanted to carry with my mini trailer.

 

[Simon Thomas]

As usual, I started with my build by ordering the materials that I need.

I have a few more materials, only had chance taking this photo.

 

[Simon Thomas]

I chose the floor dimension at 3' X 4' should be good enough. Height is 1.5'.

 

[Simon Thomas]

I spent my weekend finishing welding the frame. Welding work is not something regular for me, so it is good to weld slowly.

 

[Simon Thomas]

I intend to use the motorbike suspension as part of my build. It is easily available here and considering this is low cost build, I should visit the scrap metal shop and get a pair of second hand motorbike suspension system.

Something like this. Suspension would help my mini trailer to travel on the rough and terrain area without get broken. Of course I need to ensure that the load does not exceed the limit.

 

[landuse]

Great to see you back Simon. I look forward to setting how your trailer works out for you. You won't have a problem doing it, as I know how well your other buggy turned out after some trial and error

 

[firemanjim]

This is a touchy build.... The weight distribution on the trailer needs to be just right so it has no effect to the motorbikes suspension. Wrong, and it could seriously injure you or worse. Another important aspect to this is, how are you attaching this to the bike? On the swing arm or main chassis? IIRC, it should be on the chassis. I installed a trailer hitch on my uncles Harley Davidson and it bolted to the chassis. The trailer holds 100%of its payload and only has about a 20pound tongue weight. It's a big bike, but you can't tell the trailer is back there and he loads it down with the max capacity. IIRC, it's like 300-400 lbs... We also pull a BIG wooden Santa sleigh behind it, all around town..... LoL

 

[Simon Thomas]

Hi Firemanjim, thanks for the advice. I believe you have experience in this.

From my observation, a normal pair of motorbike suspension normally can take-up load about 200kg (based on 2 adults riding the motorbike at a time). Assuming the weight of the trailer frame alone is 20-30kg, I should not allow my load seating on my trailer exceeding 170-180kg, or go for less load if possible.

I prefer to attach it to the motorbike chassis.

 

[landuse]

Hi Firemanjim, thanks for the advice. I believe you have experience in this.

From my observation, a normal pair of motorbike suspension normally can take-up about 200kg (based on 2 adults riding the motorbike at a time). Assuming the weight of the trailer frame alone is 20-30kg, I should not allow my load exceeding 170-180kg, or go for less load if possible.

I prefer to attach it to the motorbike chassis.

How in the heck does that scooter even move!!!

 

[firemanjim]

You need to see what the weight capacity is for the shocks. That, and the tires, are what's carrying the weight. My uncles trailer is rated for 400lbs. His bike can pull a heck of a lot more than that.

The key thing is a balance of weight on the trailer, so there is no ill effect to the bikes handling, ultimately causing you much pain. You only want minimal tongue weight. Just enough so you know the trailer wont try picking up the back tire of bike. And not so much that it pushes down on bike with force, when stopping abruptly. 2 VERY important things to consider.
Once you build the trailer base, with wheels attached, you can play with placement of box, fully loaded, to see where to put it for proper tongue weight.
What kind of bike do you have? How heavy is it and what the engine size? Is it 2 or 4 stroke? Automatic or standard? These things play into the build as well. No since in build to pull a 400 pound pay load if your engine will only pull 200 on a good day.....

 

[Simon Thomas]

How in the heck does that scooter even move!!!

Paul, this photo is probably good for making us laugh and not for real ride

 

[Simon Thomas]

You need to see what the weight capacity is for the shocks. That, and the tires, are what's carrying the weight. My uncles trailer is rated for 400lbs. His bike can pull a heck of a lot more than that.

The key thing is a balance of weight on the trailer, so there is no ill effect to the bikes handling, ultimately causing you much pain. You only want minimal tongue weight. Just enough so you know the trailer wont try picking up the back tire of bike. And not so much that it pushes down on bike with force, when stopping abruptly. 2 VERY important things to consider.
Once you build the trailer base, with wheels attached, you can play with placement of box, fully loaded, to see where to put it for proper tongue weight.
What kind of bike do you have? How heavy is it and what the engine size? Is it 2 or 4 stroke? Automatic or standard? These things play into the build as well. No since in build to pull a 400 pound pay load if your engine will only pull 200 on a good day.....

There is trueness in this view. Will take them into consideration for my build.

 

[firemanjim]

I'll help you as much as I can, just ask.... If I don't see it here, send me a PM to come look......

 

[machinist@large]

You need to see what the weight capacity is for the shocks. That, and the tires, are what's carrying the weight. My uncles trailer is rated for 400lbs. His bike can pull a heck of a lot more than that.

The key thing is a balance of weight on the trailer, so there is no ill effect to the bikes handling, ultimately causing you much pain. You only want minimal tongue weight. Just enough so you know the trailer wont try picking up the back tire of bike. And not so much that it pushes down on bike with force, when stopping abruptly. 2 VERY important things to consider.
Once you build the trailer base, with wheels attached, you can play with placement of box, fully loaded, to see where to put it for proper tongue weight.
What kind of bike do you have? How heavy is it and what the engine size? Is it 2 or 4 stroke? Automatic or standard? These things play into the build as well. No since in build to pull a 400 pound pay load if your engine will only pull 200 on a good day.....

There is trueness in this view. Will take them into consideration for my build.

I'll help you as much as I can, just ask.... If I don't see it here, send me a PM to come look......

From a handling/ stability stand point, you should calculate ~5 to 10% of the intended load forward of the trailer axle center line. Neutral, or even worse rear weight bias causes potentially dangerous handling issues.

From all the studying I've done, figure on a 60/40 weight bias towards the front from the axle center line. This isn't an absolute, it just keeps popping as a good general guide line. Your results may vary.......

 

[OzFab]

Welcome back Simon...

Once you build the trailer base, with wheels attached, you can play with placement of box, fully loaded, to see where to put it for proper tongue weight.

Somewhat...

You need to find the balanced centre of the structure, not the measured centre; if you place the axle in the centre of the box, the front will be heaveir once you add the pull bar; likewise, if you add the pull bar then find the measured centre of the entire length, the rear will be heavy...

It takes a bit of trial & error but, if you simply place the axle under the completed frame (with pull bar & panels attached) you should be able to lift the front with ease but, with a slight resistance;

If it feel heavy, move the axle forward
If it's too light, move the axle back

Keep in mind, 1/4" can mean the difference between too light & too heavy...

 

[Poboy kartman]

How in the heck does that scooter even move!!!

His feet are on the ground....that's how.....

 

[firemanjim]

Welcome back Simon...



Somewhat...

You need to find the balanced centre of the structure, not the measured centre; if you place the axle in the centre of the box, the front will be heaveir once you add the pull bar; likewise, if you add the pull bar then find the measured centre of the entire length, the rear will be heavy...

It takes a bit of trial & error but, if you simply place the axle under the completed frame (with pull bar & panels attached) you should be able to lift the front with ease but, with a slight resistance;

If it feel heavy, move the axle forward
If it's too light, move the axle back

Keep in mind, 1/4" can mean the difference between too light & too heavy...

That's what I meant, you just put it in better understanding words.....

 

[Poboy kartman]

Simon....couple of things.....you can build your running carriage onto angle iron and put differently spaced holes in your frame to move it forward or back to accommodate your load....

Also....with a motorbike trailer...either the ball or the hitch needs to be able to rotate....so you can lean the bike.....

 

[itsid]

while I fully agree, that you should care about the placement of the axle according to the box.
I'm not sure it's as important as it sounds honestly.

whatever will be carried with the trailer, not only has a specific weight, it also has a specific weight distribution.
So loading the tiller in forward or backwards will make a significant difference on the tongue weight in itself.
And since I believe it's not a snug fit, you can even move it a few inches to lower or raise the weight on the pull bar,
and again I don't think we talk about ounces of difference here once loaded.

Somehow I have that "flying donkey"-pic in mind right now...
make sure it doesn't happen.
center the axle under the box, maybe half an inch towards the back, and call it a day.
let the pull bar be your frontweight for the empty trailer and take good care about how to load it properly.

'sid