Caravan movers slipping on a slope

[primal242]

I recently purchased a Adria Adora 492DT and as part of that purchase had Quattro Platinum caravan movers installed. The movers are basically for manoeuvring the van down a difficult driveway for storage.

At first attempt, there was some slipping of the movers against the tires. My driveway is mostly a 5 degree downward slope and here the movers work flawlessly. There is one short section at 9 degrees where they slipped. At the time the van weighed 1650kg. I backed the caravan down the slope and the movers are installed in front of the wheels, if that makes a difference. The driveway is between two houses so any sudden slip saw the shiny new caravan lurch suddenly toward one of the houses.

The gap between the disengaged movers and tyres seems correct at 20mm.
The tyre pressures were different in each wheel. One side 46psi and the other 55psi which is not ideal. The recommended tyre pressure for the van is 58psi and the tyres have a maximum 65psi rating.
The tyres, being brand new, are oily to touch and the tread pattern is very smooth. They are Ovation V02 which are sometimes described as low rolling resistance.

Need some advice on how best to avoid slippage.

Is 1650kg at 9 degrees (16%) too much? Specs say 2250kg (flat) or 1500kg on a 25% incline so it is on the upper side.
I need to fix the tyre pressure, but what pressure is best - 58psi (recommended) or 65psi (maximum)?
Does it make any difference if I take the van down the hill frontward vs backward?
Are the smooth, oily, low rolling resistance tyres contributing to the problem?

Appreciate any assistance.

 

[Dustydog]

Welcome to the Forum.
I checked the specification of your mover. It does not tally with your statement. Eg max incline is way below the slope of your drive. Can you explain the disparity?
Did you tell the Dealer your requirements?
The tyre pressures should be set to Adria’s recommended pressure not the tyres maximum rated pressure.
All new tyres look shiny but that doesn’t degrade their adhesion properties.
Is your drive a solid surface or gravel?If the Jockey wheel is dragging you can try reducing the nose load but only for use with the mover not towing.
I think with a bit more info many on here will be able to offer suggestions

Quattro® Platinum • Quattro Caravan Movers

Making caravan moving even easier. The Platinum caravan mover can be electronically engaged from the handset for hassle free manoeuvring

www.quattromover.co.uk

 

[Martin_E]

One question I would ask is are you sure it was the mover rollers slipping on the tyre.
The reason I ask is on two wheel drive mover fitted to a twin axle caravan there are situations where the weight comes off of the wheels, this allows the to loose traction or paddle. Prime example would be a drop kerb when for instance the back wheels (no driven) reach the higher part of the slope, the drive wheels (front axle) lift and paddle.

 

[primal242]

The specification was from the Australian website.

Quattro Platinum Caravan Movers | Remote Caravan Movers | Purple Line Australia

The caravan mover of choice for big Aussie vans up to 3000kgs on twin axles that drives the wheels of the van directly.

www.purpleline.com.au

It says "up to" 1.5 tonnes on a 25% incline. I note the UK website says something different.

There are very few caravan movers available in Australia and this was the one that could move the most. It is sounding like it is at its limit.

Driveway is concrete and in good condition.

 

[primal242]

One question I would ask is are you sure it was the mover rollers slipping on the tyre.
The reason I ask is on two wheel drive mover fitted to a twin axle caravan there are situations where the weight comes off of the wheels, this allows the to loose traction or paddle. Prime example would be a drop kerb when for instance the back wheels (no driven) reach the higher part of the slope, the drive wheels (front axle) lift and paddle.

It is definitely the mover roller slipping against the tyre, I have been beside the van when it is happening.

 

[JTQ]

On one point you raise, there is a distinct benefit coming down a slope travelling forward. That way the handbrake is more effective and responsive.
Whilst obviously it needs doing with care, I would stand in front and just to the side of the van in such a position I could apply the handbrake swiftly if the creep hints as going wrong. As said with great care that the van will not roll over you. Here placing bricks equally spaced in front of the wheels as emergency stops might be wise; moving them prior to reaching them but there should things go wrong.
If this is happening in the dry, be warned it will be considerably worse with wet tyres, then I definitely would be using "emergency" stops, if unable to put off moving the van.

Increasing the pressure ought help increase the grip as it ups the load of the roller onto the tyre and with that the friction between them.

As it is slipping on the tyre, it is not directly a traction capability issue with the mover other than the "grip" to the tyre, more one with the roller detail design or how hard it is pushed against the tyre. How well does it climb this increased slope, that it slips down?
I would be raising this with the supplying/fitting dealership, even if they subcontracted any part of the task; basically, it's their problem at the moment.

 

[Beardy]

The tyres, being brand new, are oily to touch and the tread pattern is very smooth.

This can't be helping. Car and motorcycle tyres should be 'scrubbed in' for 150-200 miles before being pushed hard due to their reduced traction. I've known people use fine grade emery cloth on new tyres but manufacturers recommend against doing it due to potentially damaging the tyre.

 

[otherclive]

This can't be helping. Car and motorcycle tyres should be 'scrubbed in' for 150-200 miles before being pushed hard due to their reduced traction. I've known people use fine grade emery cloth on new tyres but manufacturers recommend against doing it due to potentially damaging the tyre.

I’ve always gone by the 50 mph max for 50 miles distance to wear in new tyres. I recall a police car had an accident when it was fitted with new tyres but the crew were not briefed so drove normally and lost grip. Fortunately no one was hurt.

 

[ProfJohnL]

Having the correct distance between the roller and tyre is important, and why it should be adjusted as tyres wear, but the bulk of the force that generates the grip between the tyre and roller is created by the pressure in the tyre. If the pressure is too low it will reduce the rollers grip on that tyre' so it's also important to keep tyre pressures correct. Follow the caravan maker's advice regarding the pressure you use.

The fact you have new tyres which may still have some molding release contamination won't help the situation, but this should fairly quickly be sorted with just a few miles towing.

Caravans with overrun brakes manufactured for sale in the UK and EU are also usually fitted with automatic reversing systems, which allow a tow vehicle to push back against the applied brakes which causes them to release for reversing. Whether this system is in use in other parts of the world I do not know, but if it is, then I recommended always trying to keep the caravan facing hitch down an incline when manhandling or using a mover, so that if the hand brake is applied, the caravan should not roll backwards and possible disengage the brakes.

The great benefit of using a road wheel mounted mover compared to an "A" frame or replacement jockey wheel mover is the amount of weight it carries and thus traction/braking action it can achieve. More weight = more grip and control and that becomes very important when negotiating inclines. It isn't a question of power to move the caravan, arguably it's more important to be able to control and stop the caravan safely on the incline.

You haven't actually told us if your mover has a drive unit on each wheel or whether it only drives two wheels of your twin axle caravan. If all four wheels are driven then notwithstanding my suggestion above about which way round to maneuver on an incline, a four motor setup should not mind which way it drives.

There are some Twin Axle movers which only have two motors, and then there is a decision about which axle to fit it to. If the manufacturers instructions tell you then follow those otherwise warranty may be affected. But if there is no other formal advice, my suggestion is to fit a mover to the pair of wheels that carries the most loading. With a twin axle if it's uncoupled from the tow vehicle, raise the jockey wheel. In most cases the caravan will begin to drop its nose which points to the front axle as carrying the most load, This should be normally the case, and that is where I would fit the mover.

When using the mover on a twin axle I suggest raising the jockey wheel to reduce the load on it which can help negotiating corners and on softer ground.

 

[Dustydog]

Err correct me but isn’t the OP Adria a SA?
Certainly his mover is only a two motor

 

[Beardy]

With a twin axle if it's uncoupled from the tow vehicle, raise the jockey wheel. In most cases the caravan will begin to drop its nose which points to the front axle as carrying the most load

Trying to get my head around this but I can't. Surely if it's uncoupled from the tow vehicle the caravan nose will always drop as you raise the jockey wheel (I'm interpreting 'raise' as retract the jockey wheel). I guess that if it was perfectly balanced it could remain stationary, but that would mean you were towing with zero nose weight. How can a caravan raise its nose as you retract the jockey wheel?

 

[Beardy]

Err correct me but isn’t the OP Adria a SA?
Certainly his mover is only a two motor

I think a few people misread this bit in the original post.

the movers are installed in front of the wheels

 

[Hutch]

The tyre pressures will make a big difference to the grip or the motor movers. I would try the recommendation of 58 psi.,

 

[trevormonty]

Given you are backing it down driveway can you use tow vehicle with tow rope as anchor. Best done with 2nd person in tow car to keep slack in rope short as possible.

 

[primal242]

To answer a few questions.

It was dry at the time, good to know it will be worse in the wet.

Two wheel single axle caravan.

Caravan has an Alko chassis with the automatic reversing system that comes with European vans. It is the same as a European van except with thicker steel in the chassis. (A big fan of the European vans, previous van was a 2000 Lunar).

It would have been easy to reverse the van down the driveway with the handbrake partially engaged, but the Alko chassis has one of these “all or nothing” handbrakes, can’t seem to partially engage it.

The van was towed for three hours freeway driving from the dealer when I picked it up, so there is some wear on the tyres. I used the “Brick behind Wheel” method and edged the caravan down the steep bit without incident. Today I am leaving for a 2000km trip so I will see how they work on my second attempt upon return in a few weeks time. Worst-case scenario is I need to use a combination of caravan mover and hitched to car to get the van in the back yard. The steep part of the driveway is straight (hitch to the car), the difficult-to-manoeuvre part of the driveway is less steep (caravan mover).

Appreciate the feedback

 

[otherclive]

To answer a few questions.

It was dry at the time, good to know it will be worse in the wet.

Two wheel single axle caravan.

Caravan has an Alko chassis with the automatic reversing system that comes with European vans. It is the same as a European van except with thicker steel in the chassis. (A big fan of the European vans, previous van was a 2000 Lunar).

It would have been easy to reverse the van down the driveway with the handbrake partially engaged, but the Alko chassis has one of these “all or nothing” handbrakes, can’t seem to partially engage it.

The van was towed for three hours freeway driving from the dealer when I picked it up, so there is some wear on the tyres. I used the “Brick behind Wheel” method and edged the caravan down the steep bit without incident. Today I am leaving for a 2000km trip so I will see how they work on my second attempt upon return in a few weeks time. Worst-case scenario is I need to use a combination of caravan mover and hitched to car to get the van in the back yard. The steep part of the driveway is straight (hitch to the car), the difficult-to-manoeuvre part of the driveway is less steep (caravan mover).

Appreciate the feedback

Enjoy your long tour.

 

[ProfJohnL]

Trying to get my head around this but I can't. Surely if it's uncoupled from the tow vehicle the caravan nose will always drop as you raise the jockey wheel (I'm interpreting 'raise' as retract the jockey wheel). I guess that if it was perfectly balanced it could remain stationary, but that would mean you were towing with zero nose weight. How can a caravan raise its nose as you retract the jockey wheel?

What I have describe only applies to twin axles and its the result of the interaction of the the suspension on each axle. Yes, the hitch should drop below its towed height, but what might surprise many is how far it drops. Instinctively you might expect it to fall to the floor, but many will only drop a few centimeters leaving the hitch floating in the air.

 

[ProfJohnL]

Err correct me but isn’t the OP Adria a SA?
Certainly his mover is only a two motor

At the time I read the post there was mention of a Quattro mover with a link to an australian site concerning twin axles.

 

[Hutch]

Sorry Prof , you have read the post wrong, again, The QUATTRO, is the make, the information given is fully clear, you have jumped the gun, thinking it is for a twin axle.
I tried to check the wheel and tyre size, and it is 215/70/15C , which is not a common size to the UK. But obviously suitable for such a heavy caravan.

 

[Martin_E]

To answer a few questions.

It was dry at the time, good to know it will be worse in the wet.

Two wheel single axle caravan.

Caravan has an Alko chassis with the automatic reversing system that comes with European vans. It is the same as a European van except with thicker steel in the chassis. (A big fan of the European vans, previous van was a 2000 Lunar).

It would have been easy to reverse the van down the driveway with the handbrake partially engaged, but the Alko chassis has one of these “all or nothing” handbrakes, can’t seem to partially engage it.

The van was towed for three hours freeway driving from the dealer when I picked it up, so there is some wear on the tyres. I used the “Brick behind Wheel” method and edged the caravan down the steep bit without incident. Today I am leaving for a 2000km trip so I will see how they work on my second attempt upon return in a few weeks time. Worst-case scenario is I need to use a combination of caravan mover and hitched to car to get the van in the back yard. The steep part of the driveway is straight (hitch to the car), the difficult-to-manoeuvre part of the driveway is less steep (caravan mover).

Appreciate the feedback

Don’t be tempted to use the handbrake on and off while the van is going down hill backwards, this can invoke the auto reverse mechanism!!

 

[JTQ]

Don’t be tempted to use the handbrake on and off while the van is going down hill backwards, this can invoke the auto reverse mechanism!!

Which can so readily snatch your wrist, as it will violently set full on, faster than you could.
Plus, moving astern, it only uses one shoe per drum not both, so its performance is potentially lower.

 

[Martin_E]

Which can so readily snatch your wrist, as it will violently set full on, faster than you could.
Plus, moving astern, it only uses one shoe per drum not both, so its performance is potentially lower.

My point being you will have no brakes 😮

 

[Gafferbill]

I personally would not take my caravan backwards down a slope like you describe.
There is much safer and better control if you take your caravan down forwards on the mover with the caravan's hand brake readily to hand.
I personally would reduce the disengaged gap to 17mm and definitely make sure the tyres are correctly inflated to 58-60 psi.

 

[JTQ]

My point being you will have no brakes 😮

Only if miss set up. The system set up correctly ought to work but as stated not with as effective performance as from rolling forward.

Here from what the OP had said I conclude he has the gas strut power version not the older ratchet one?
That earlier version, if not fully applied was particular prone to as you say, to "have no brakes", in it required you to more than apply it, but also have loaded up the energy storage spring. Always good to do even in the later ones.
The gas strut one will to an extent apply the additional movement, lost in the shoe "falling away" on reverse rotation, but as I warned with a kick like a mule, hence potentially wrist damaging if still held.

An incident I witnessed in the ratchet brake days where after unhitching on a slope a van with partly applied handbrake rolled rear end first down the field, thankfully missing all the other vans in that rally. Once seen, now I will never pitch rear downhill, at least not without grossly over wedging both wheels rears.

 

[Ferrodo]

Just a thought…… I assume that the movers are moving their full stroke? In other words getting to apply their full force on the tyres. There isn’t any reason why the working stroke is being impeded is there. Maybe remove a wheel, operate the movers and see.