quad forwarder

[b101uk]

Its a timber cart not not a rally car some people take things far to seriously,just bodge it up to pull a bit of timber its bound to be better than a wheel barrow.

 

its yours or anyone else’s choice if you choose to disregard wisdom I have tried to impart, I am more than happy to say “I told you so” if it all goes wrong which I hope it wont either threw the police/VOSA stopping you on the road or some innocent person getting killed because you have disregarded something or think you know better or just that it wont happen to you.

 

On other threads regarding ATV forwarder trailers I have pointed out the dangers of only using over-run brakes instead of power brakes given the former don’t work in reverse so WILL happily drag you and your ATV backwards down hill if you your ATV doesn’t have the mass & factor of adhesion to hold the load and if you have NO trailer brakes then when travailing up or down hill you are at much risk.

 

There has been many a farmer etc killed and injured and many machines written off on gentle grass slopes due to unbraked trailers pulling them backwards down hill.

 

 

 

[Charlieh]

the electric brake assembley kits arent very expensive from the states, do they just act on the brake light circuit, through a relay to a 12v supply from the battery or does it involve more wiring than that?

 

also how would i go on, using a braked trailer on the road whilst not wanting to exceed the 750kg limit, are their braked 750kg axles out there?

[Stephen Blair]

that is a shocking eye opener

[ukminch]

It is indeed scary those pictures say a lot. Guess it all depends on what the original poster wanted to do with it though. If your bringing 200kgs of logs out along a track possibly not an issue, if it's more then well, the above pics speak for themselves.

 

Never even thought of the above scenarios.....

 

R

[b101uk]

Many cars cannot tow 750kg unbraked as that is the absolute legal maximum, many cars can only tow in the region of 450kg to 650kg unbraked so there are plenty of axels out there that have brakes even though they are rated at 750kg or less.

 

If you think logically a car will weigh much more than the unbaked trailer it can tow ware as an ATV will weigh much less than the trailer they are asked to tow even with the rider on it, the unbaked trailer capacity of ATV is very small if you look at the machine specs.

 

Lets say your ATV weighs 250kg (without rider) and is 4x4 with brakes on all wheels, on tarmac or other hard dry ground it will be good for ~75% of its weight to convert into any form of traction, thus with its brakes locked you will yield 187.5kg of holding force, on dry grass it will yield ~35% of its weight to convert into traction or 87.5kg of holding force, if it lightly rains on that grass the adhesion will drop much lower down to ~25% or ~62.5kg of holding force.

 

Now if you bare the above paragraph in mind and its simple concept of converting mass in to adhesion (grip) base on the factor of adhesion % that a surface will yield wile reading the paragraph below you will realise why people get into trouble with trailers and slopes especially when condition change with a little bit of rain.

 

As most of you know when the vehicle you are driving comes to a hill it slows down, the steeper the hill the more power you need to maintain speed and the greater the affect of slowing down is in the absence of sufficient power, slowing down happens because unlike travailing on the flat ware the effects of gravity are negated a % of gravity based on angle of incline will be working to resist you assent, a vertical incline (90deg) will yield 100% of gravity or in ATV terms relating to this thread and the above example that would be 250kg + 750kg of trailer equalling 1000kg pulling you down and because of the absurd angle (mealy for the point of illustration) non of that mass would be acting on the wheels, on a 45deg slope the effects of gravity are 50% so you have 50% of your total mass trying to pull you down hill or in other words 500kg of force, on a 22.5deg slope you have 25% of your total mass trying to pull you down hill or in other words 250kg of force and logically if you are keeping up with the above you realise that on a 11.25deg slope it is 12.5% of your mass trying to pull you down hill (125kg) and for a 5.625deg slope its 6.25% of your mass (62.5kg), so in short for each 1deg of slope you get 1.111111% of your mass acting agenised you to pull or push you down hill.

 

So in a situation ware you are using an unbraked trailer a modest slope on e.g. grass it can be a killer especially when conditions have changed during a working day due to a bit of light rain, if you have brakes on your trailer then any weight on the trailer generates braking force in addition to the ATV so if you look 3 paragraphs above (Lets say your ATV weighs 250kg………..) and if you work the % for a 750kg loaded braked trailer in addition the ATV it makes a marked contrast in holding force given in the example the trailer weighs 3 times more than the ATV

 

Just remember the calculation for holding force vs. ground factors MUST exceed gravity’s pull or you will be at its mercy.

 

Just in case any one wanders, the drivers of the tractors in the pictures all survived yet you can see even a ROPS’s cab can only do so much and an ATV doesn’t have a ROPS or much else and 750kg of trailer is more than enough to kill you if it runs you over or impacts you agenised a tree all for the want of some brakes!

[ukminch]

I think the problem that you have there though is that even if the trailer was braked it's not going to help as the friction still not be enough to even keep you stationary?

 

R

[Buzzsurgeon]

Flat as a pancake in the woods where I work so don't have to worry about super gravity shunting me around!

[raafbeard]

Good posts B101....eye opening and interesting.

 

Sure you could make something of use with that frame David just beware the limitations as illustrated..

[Andy Collins]

On the topic of the ROPS, my understanding at this time is that they have looked into this for atv's, but in trials the risk of trapped limbs has out-numbered potential fatal injuries. How accurate this is i dont know. Ridden correctly, with EASI training, reading and understanding AFAG leaflets, atv's are no more dangerous than any other power equipment. Using information such as B101 has posted can only help us to be safer in our operations.

I saw a converted caravan chassised trailer yesterday with about a tonne of sand onboard, behind a Mondeo estate and tbh that looked bloody dangerous, the suspension looked totally over-whelmed and the chassis was wringing under the weight, and this was on the road.

[Andy Collins]

I've just searched through several sites including the HSE for relevant stats on this subject. From what I can find 1 incident of losing control of atv with trailer, due to unsecured load. The majority of accidents are head injuries as a direct result of not wearing head protection, under 16's operating atv as toys. The HSE predicts 2 deaths per year as a result of atv accidents. Crush injuries occur, such as Ozzie Osbourne, where the vehicle turns over, due to too much speed, incorrect tyre pressures, and driver error. In the States 30% of all atv-related accidents were due to alcohol/drug use by the operators. One child crushed her mother in this country, by blipping the throttle while the engine was running, causing the machine to run forward trapping the mother against a solid object.

It seems the stats for atv's in this country block all recreational and professional machines together, mixing in ag machines of al types depending which stats you research.

Be safe, wear the headgear, keep the speed down, and plan your route to suit your work.