Thinking of doing something memorable like riding my trail bike across the Simpson for when I'm 60 next year.
This will mean need for a strong trailer capable of carrying any broken down bikes to be towed behind my GU Patrol which will be the support vehicle.
I am toying with idea of modifying a standard low cost 50mm ball coupling or similar to increase its angular articulation for a purpose built trailer I am making to cross with.
(While O'brien or tregg are great they are $200)
Wondering if others have done this, or crossed with standard system.
Robin Miller
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DESIGN NOTES
After some research we are proceeding with the following rough plan for building the trailer and would welcome input to its design.
The overall concept will be to build a flat rectangular TIG welded frame which will then have a braced 65mm x 3mm wall square drawbar of length such that it will allow the trailer to
swing side to side almost 90 degrees such that it will not hit the car.
The bike holding bits will be bolt on and designed to be removed and trailer will ultimately be configurable as a camper as a later project.
The cost of the basic operational frame will be $1000 (ex-
wheels)
The weight of the trailer will be 400kg unloaded - 800kg loaded. Its unbraked and its basic width will be that of the car @ 1900mm with wheel track 1650 (same as car) so that trailer
wheels will follow in car tracks.
The trailer frame top surface will be designed to be level with the
wheels at 800mm which combined with width will just
Wheels will be 16X7 trak 11 steel rims running 235/85/16 tyres with spare capable of going on the car.
Suspension is a major issue and have decided to go with commercial 40mm square solid axle on leaf springs with shocks and landcruiser hubs with optional larger bearings(non-chinese)
with 165cm between the two wheel mating faces.
While there are some advantages with independant
suspension we have concluded that main issue as with cars is to have a
suspension setup that allows for real flex with the intended load.
Design will be to have 50mm of
suspension downtravel from unloaded trailer to loaded.
Hence expect to use long leaf (Holden ute) with fip over spring hangers and using just the appropriate number of leaves which will be determined later. An effective extra 50mm will
come from the tall 85 profile tyres with a total effective
suspension travel of 200mm vertical and 30mm horizontally.
The axle will be slung under
the springs to increase ground clearance and to allow for spare wheel to be carried either behind or forward of the trailer frame (this allows for adjustment of towball weight to around 50kg).
The frame will be constructed such that the spare wheel will fit inside its perimeter not below it.
Coupling - haven't decided on this yet although have been looking at a full swivel O'briens off-road unit rated at 2500kg but this looks a little heavy and expensive at $205 retail.
The coupling will be on a bolt on plate and allow for a standard trailer ball unit to be used instead.
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