Hello all,

I hope I'm not misusing this Techies corner. My brother is hoping to add an extra 100L water tank to his camper. Would there be an issue with placing it above the axle? There appears to be 70-80mm clearance left. He has a leaf spring suspension with shock absorbers. If the axle was to travel that far, wouldn't there be bigger issues to worry about?
Will

well two questiions arise here Will (1) 100 ltrs equates to 100 kilograms of extra weight, how much drawbar loading has he at the moment, if he is up to his max already he will have to "juggle the weight towards the back or if he is well under then to equalise the weight he will have to "juggle" it towards the front, do this until he has roughly 10% of total trailer weight (fully loaded) on the towball (2) clearance will become an issue over rough terrain when fully loaded, 70 - 80 mm equates to 3 - 4 inches, not enough I'm afraid even running down the highway it will "belly out" on the tank, can he install the axle beneath the springs (they are currently on top of the leaves I assume) if he places them beneath then he will gain an extra 50 mm (size of axle thickness, assuming a square axle), the other way is to place a set of "helper springs" on, these will give him an extra 30 mm plus, these numbers are assuming a lot of things, depending on the size and load capacity of the springs, if they are rated at 750 kilograms and the trailer is weighed in close to that then they will travel that far, if they are rated at over 750 and the trailer is less than that then the travel will not be as great and he would need to do nothing, anyway hope I've helped just a little

Sir, your blood's worth bottling. Thanks for that Dave. We have spoken about ball weight, and he is a little on the heavy side. We can place the tank at the rear of the camper, we would need to shift a couple small springs.(Cub Camper- not sure which model). I know he was concerned with his departure angles, but I'd be more scared of his passenger who would be worried about her kitchen. There are helper springs already fitted, and I will check to see if he can spin the axle over. I believe he may run into trouble with the height for the rear flip over, and it may sit a bit high behind his std 100 series. To be honest I'm surprised the axle would travel that far. I have no basis for this, just never really thought about it. So please humour me Dave, if the axle traveled the 70mm so that it bellied out the tank, wouldn't the springs be virtually flat like the old LJ50? Regards Wil

well they would only do it momentarily as the weight bares down and then comes off again you would be surprised at just how far these things travel (up and down) but that is where you would get a rupture in the tank IF it was travelling that far, I have no way of knowing so I must advise accordingly, it will be retarded to a fair ammount because of the shockers if he is already up to or close to his or close to his ball weight allowance then he has no option but to fit it to the rear, the balance and ball weight must be kept correct whatever he does but I must err on the weighty side, giving the worst case scenario otherwise it will be my fault if it ruptures it all depends on the weight of the trailer and the stiffness of the springs, stiffer springs + less weight = less movement, soft springs + heavy weight = great movement the departure angle can be easily overcome if he fits a "belly plate" just a simple sheet of steel with maybe a couple of skids to protect the underside of the water tank another thing that I have seen and may possibly help your freind are rubber buffers placed in a strategic position so as to limit the axle travel, simply a peice of steel positioned on top of the axle in such a way as to impede the overall upward travel and thereby stopping it hitting the tank make sure you put large rubber thingys on the top or it will drive him mad

Thanks again Dave, I'll look into the bump stop idea. We were planning on the protective plate, so it looks like it may still be heading towards the rear. Regards Will

It is fact that these numbers are assuming a lot of things, depending on the size and capacity of the piers, if they are valued at 750 pounds and the trailer is weighed in the fence that will travel as far, if they are valued at more than 750 and the trailer is less than the continuation of the journey will not be so large and would have to do anything.