The best loopholes for using dads tractor as a lorry. DVSA please don't look in here.

[JD450A]

Trouble is as said before, unimogs aren't meant to have superimposed weight like a tractor. Idea is that the hitch is positioned to give positive tractive weight from the pull point not vertical loading.

Think how a wagon and drag works

 

[Smiffy]

Trouble is as said before, unimogs aren't meant to have superimposed weight like a tractor. Idea is that the hitch is positioned to give positive tractive weight from the pull point not vertical loading.

Think how a wagon and drag works

But you need some sort of weight for grip. Either imposed, deck weights, wheel weights or front weight block. A 150hp tractor certainly handles like a pig towing a trailer with no weights on. And unimogs generally handle like a pig regardless. Atleast the older ones that Ive driven, the ones with chip boxes on are horrendous when compared to a lorry carrying the same.

 

[JD450A]

The best way to explain it is the original MF theories in 3pt linkage weight transfer. Same with tractors albeit to a lesser extent and depending on application it's opposite.

A unimog with a low slung agricultural pickup hitch towing a agricultural tandem or single axle unbalanced trailer will put plenty of weight on the arse, however it will also squash the suspension resulting in below par tractive effort.

A balanced trailer or dolly trailer with a hgv hitch or pin at or above axle height will give similar characteristics to a lorry and yeild better tractive effort whilst also not affecting the unimogs suspension.

This is also why most European tractors used with dolly trailers feature a high mounted hgv type hitch, and those used industrial purposes do so. Putting tons of weight on the tow vehicle doesn't always lead to more tractive effort. Sometimes it's the opposite and detracts from it.

 

[Smiffy]

The best way to explain it is the original MF theories in 3pt linkage weight transfer. Same with tractors albeit to a lesser extent and depending on application it's opposite.

A unimog with a low slung agricultural pickup hitch towing a agricultural tandem or single axle unbalanced trailer will put plenty of weight on the arse, however it will also squash the suspension resulting in below par tractive effort.

A balanced trailer or dolly trailer with a hgv hitch or pin at or above axle height will give similar characteristics to a lorry and yeild better tractive effort whilst also not affecting the unimogs suspension.

This is also why most European tractors used with dolly trailers feature a high mounted hgv type hitch, and those used industrial purposes do so. Putting tons of weight on the tow vehicle doesn't always lead to more tractive effort. Sometimes it's the opposite and detracts from it.

It depends as depending on the manufacturer of the pickup hitch on unimogs some are axle mounted. The same as the lower link arms on some mogs are on the axle.

And the idea of the low slung hitch is to pull the front wheels down to stop rearing up. Whereas the high euro hitches will lift the front wheels. Different benefits for different applications but a lot of European tractors are now going to low slung ball and spoon hitches so our way can't be that bad.

 

[JD450A]

It depends as depending on the manufacturer of the pickup hitch on unimogs some are axle mounted. The same as the lower link arms on some mogs are on the axle.

And the idea of the low slung hitch is to pull the front wheels down to stop rearing up. Whereas the high euro hitches will lift the front wheels. Different benefits for different applications but a lot of European tractors are now going to low slung ball and spoon hitches so our way can't be that bad.

You'll find that's because more and more Europeans are opting for tri axle unbalanced trailers.

In relation to the axle I mean height off the ground more than the mounting points.

 

[Smiffy]

In relation to the axle I mean height off the ground more than the mounting points.

I was referring to your comment of squashing the suspension. If the pickup hitch is the axle mounted type you won't squash the suspension.

And it's more a chicken and the egg thing with European trailers. They have moved over to ball and spoon as they are a better hitch and are making trailers to suit. There are unbalanced trailers that use a vbg style hitch. But the hitch point has got lower over the years. Hence why European tractors have an adjustable height hitch on two rails.
But it's a horrible setup.
Far less maneuverable than an underslung hitch.
You also get the problem that if the tractor breaks are sharper than the trailer breaks you pick the back of the tractor up. Really not fun if you are turning. Whereas an underslung hitch the trailer tends to push the tractor down in the same circumstances which is far safer.

 

[craig]

An axle mounted Unimog hitch is not 100% mounted on the axle, part of it is still suported from the chassis.

 

[V8Druid]

top and bottom is .... the bloke thinks he's above the law ... the pic that started the discussion illustrates that in no uncertain manner ... as for the rest .. well as said at the start

 

[Bri963]

Putting tons of weight on the tow vehicle doesn't always lead to more tractive effort. Sometimes it's the opposite and detracts from it.

I think guys from Wynns, Pickfords, Sunters, ALE and a few others might query that statement, Rory.

 

[Bri963]

It depends as depending on the manufacturer of the pickup hitch on unimogs some are axle mounted. The same as the lower link arms on some mogs are on the axle.

And the idea of the low slung hitch is to pull the front wheels down to stop rearing up. Whereas the high euro hitches will lift the front wheels. Different benefits for different applications but a lot of European tractors are now going to low slung ball and spoon hitches so our way can't be that bad.

Interesting you picked up on this, in Sweden there are rigs where 8 wheel wagons are dragging 4,6, or 8 wheel trailers with No load at all imposed on the wagon, ball and spoon hitch, single drive axle, and no problems getting round on ice. I think they’re allowed 70-ish tonnes on main roads.

 

[Smiffy]

Interesting you picked up on this, in Sweden there are rigs where 8 wheel wagons are dragging 4,6, or 8 wheel trailers with No load at all imposed on the wagon, ball and spoon hitch, single drive axle, and no problems getting round on ice. I think they’re allowed 70-ish tonnes on main roads.

Lorries have their own weight though whereas tractors and unimogs are surprisingly light weight so need ballast or weight transfer.
The Americans who don't run three point hitches end up using tractors about 1.5x the size to do the same job.

 

[Bri963]

I wasn’t questioning what was said about Mogs, just thinking that it’s interesting how different solutions have developed in different countries.

 

[Smiffy]

I wasn’t questioning what was said about Mogs, just thinking that it’s interesting how different solutions have developed in different countries.

I often think about this for lots of different subjects. And sometimes it amazes me how we are such a little island yet we have so many things specifically engineered for us that noone else uses rather than just borrow stuff from europe

 

[V8Druid]

Lorries have their own weight though whereas tractors and unimogs are surprisingly light weight so need ballast or weight transfer.
The Americans who don't run three point hitches end up using tractors about 1.5x the size to do the same job.

and are therefore totally unsuitable for drawing a non superimposed load --- they'll struggle to 'boss' what they're drawing particularly in any change of direction on the flat or downhill and uphill they just can't put down the tractive force

 

[HuntingHicap]

yeh right

Anyone know how to attach an video file on here?

 

[HuntingHicap]

 

[DVSA]

just checking in to see who we can send our mobile units to next

 

[V8Druid]

Anyone know how to attach an video file on here?

load it to youtube, then link it to here ..... I'm sure DVSA 'd be grateful

 

[HuntingHicap]

load it to youtube, then link it to here ..... I'm sure DVSA 'd be grateful

The three bales on the back didn't go on the road. Lee was testing it out around the field. Realistically it probably has a legal payload of one bale.

 

[V8Druid]

The three bales on the back didn't go on the road. Lee was testing it out around the field. Realistically it probably has a legal payload of one bale.

that'd be a very big ......... perhaps!!
in fairness, as I said before, it looks a tidy-ish job, but it's totally impractical with current UK C&U reg.s and licensing for much else than towing ... a basic Disco 1 is nigh on 2 tonne and they ain't exactly a heavy tub to start with ... with that cab and body, etc, I'd be very surprised if that was much under 3t