OT - New Trailer Build Coming Soon...

Stuart Ablett

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Tokyo Japan
I knew that the trailer I'm using had some cracks in it, yesterday I did a delivery I do every six to eight weeks, a bunch of sake over to Gokokuji and back. Not that far, but with a combined weight of about 80Kg between the sake and the trailer it's a bit of a hike. On the return leg, with much less weight in the trailer I notices some tell tale squeaking, this for sure means the cracks have gotten worse.


cracks_arrows_zps00d93a67.jpg

You can see the areas that the trailer cracked, I knew it would crack here eventually, this area is kind of a weak link :eek:uch:


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This is the crack in the left side, it is not all the way through the square tubing, close but not quite all the way.


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This is the right side, yep, that is busted!


What I'll do for now is clean the paint off and then weld it some, adding even more metal to this already heavy trailer, its about 34Kg now.


addition_area_zps26b0e60d.jpg

You can see the extra metal on the right, the Blue "A" point, that is from where I hacked the trailer into three parts to make it wider to fit more stuff that I have to take on deliveries. I'll add another piece of flat steel between the Blue points "A" and "B" where the yellow arrow is on both sides, that should be good to go for another six months. In the mean time, I'm going to start getting things together to build a whole new trailer.


This time I'm going to build it out of round Chromoly 4130 tubing. I'll buy one of these hydraulic tube benders, so I can eliminate as many corner joints as possible. I'll have to get a hole saw sized to the tubing as well, to be able to fish mouth the joints.


I'll get Tim to build me some bullet proof 26" wheels, with disc brakes so I have my parking brake, can't be without that, and the whole deal should be a LOT lighter than the 34Kg I have now, and with some thoughtful engineering, I hope it hangs together longer too!
 
yesterday I did a delivery I do
...
This time I'm going to build it out of round Chromoly 4130 tubing. I'll buy one of these hydraulic tube benders, so I can eliminate as many corner joints as possible. I'll have to get a hole saw sized to the tubing as well, to be able to fish mouth the joints.


I'll get Tim to build me some bullet proof 26" wheels, with disc brakes so I have my parking brake, can't be without that, and the whole deal should be a LOT lighter than the 34Kg I have now, and with some thoughtful engineering, I hope it hangs together longer too!

w.r.t your delivery: I can't see the word Shinjuku without flashing back to a certain Tubes song... just the way my memory works! :headbang:

These disc brakes would just be for locking the wheels when stopped, right? Not for while driving? I can't see how it'd work that way.
Is the connection to the bike working out? I remember you had to re-engineer that once. Otherwise sounds like the trailer has been a good move for you. Never had any breakage on delivery?

...art
 
The last one has lasted quite a while. I think the chromoly would be a good choice, but keep in mind you'll loose corner space with rounded corners. I'm surprised you haven't been asked to make more of these for others?
 
w.r.t your delivery: I can't see the word Shinjuku without flashing back to a certain Tubes song... just the way my memory works! :headbang:

These disc brakes would just be for locking the wheels when stopped, right? Not for while driving? I can't see how it'd work that way.
Is the connection to the bike working out? I remember you had to re-engineer that once. Otherwise sounds like the trailer has been a good move for you. Never had any breakage on delivery?

...art

My brakes on the bike are hydraulic disc brakes, so somehow linking the two would be almost impossible. What I am thinking of, what I have hear of is what is called a drag brake. What I would do is put an old time friction thumb shifter on the handlebars, on a long down hill I'd just thumb some drag on the trailer brake, that might be possible, but yeah the main reason is as a parking brake. The other reason is that the Mamachari wheels and breaks are very heavy, I'd bet that one is heavier than two well made strong 26" front wheels. My buddy the wheel builder is talking about a 26" wheel with Deore XT hubs 32 spoke rims and maybe even carbon fiber rims. He has some test rims that he built up for MTBs, disk brake rims that ended up being too strong, as in over built, but they are still lighter than a comparable alloy rim. If he is willing to donate them to the cause, why not? :D

The hitch has been trouble free, it is holding up just fine, that part I got right!

I've never even had a flat tyre on delivery, I've had breakage, but I've always managed to limp home.

This trailer has been fixed, widened, broken, and then fixed again, widened once more and welded up so many times it is just a pig, a strong pig, but a pig. As it stands it is 34Kg or 75lbs, empty! I bet I can make a trailer under 15Kg/33lbs, for sure under 20Kg/44lbs and it would be better made and should be stronger too. One thing I'm going to do is make the tongue bolt on, with some sort of flexible interface, this would take up the constant stress on the joint area between the tongue and the main body of the trailer.
 
The last one has lasted quite a while. I think the chromoly would be a good choice, but keep in mind you'll loose corner space with rounded corners. I'm surprised you haven't been asked to make more of these for others?

I won't lose any space really in the corners, but the corners are not used anyway :D

I'm also trying to think of a way to add some suspension to the trailer but I've not ever come up with something that would work.

I've been asked, but I always just laugh and shake my head, where would I find the time? :eek:
 
I've been asked, but I always just laugh and shake my head, where would I find the time? :eek:

May just sell the design and find a local fab shop to do the fab for you. ;)

For suspension, what putting the wheels on their own frame, which would be hinged on the front, and add two small coil over shocks mounted on each side in the rear. My new zero turn has some pretty small coil over shocks, that are about $48 (US) each. I don't know the specs on them. The mower is about 1000 lbs and doesn't give hardly at all when I step on, but they are adjustable. I'll have to look sto see where mine are adjusted to.


http://www.powermowersales.com/page...Main_Frame_&_Front_Suspension_Group/3014/3101

Would be similar to the rear suspension on my mower. The drive units and wheels are on their own frame, and the coil over shocks connect it to the main body.


EDIT: Surplus center has some mini-bike ones for $8.95 each: http://www.surpluscenter.com/item.asp?item=28-1720&catname=wheels
 
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IMG_5351_zps921c1f4f.jpg

First project in the new welding space.


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The welding is a bit messy, mainly because I'm using 100% CO2 as my gas, it makes a lot of splatter.

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Top side

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and of course, I had no red paint :rolleyes:

Oh well.

This should hold up until I get the new trailer built.

Cheers!
 
Yep, you needed a gusset to share the pull at that point. Bet it lasts now.
On the new trailer with the hydraulic disc brakes, in the '70's we had horse trailers with hydraulic brakes (before the electric brake controllers of today) that worked off of a sliding tongue. As you applied the brakes on your car the load in the trailer caused the tongue to compress which in reality was pressing the hydraulic system for the trailer braking the trailers load for the car. The lighter the load, the lighter the push thus the lighter the braking action. Really ingenious and simple, could work nicely for your bike trailer. Could eliminate the springs and build a rubber lined torsion axle. http://www.google.com/imgres?imgurl...crxRUcXnB7OgyQHV8oGoAw&ved=0CGsQ9QEwAQ&dur=86
 
Well i dont see any need for a new one now. A gusset here or there is a lot easier. :)
Now that aint to say it would not be fun to make a new one.
Great fix. :thumbup:

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