Today was the acid test. Hitched up the trailer with it having the same weight distribution as when I did the test run last Monday - i.e. about 80 Kgs on the ball. This was over the maximum for the N/A 2.5L Fox (75 Kgs), but equal to the maximum for the 2.5L XT (80 Kgs) (see Page 8-18 of the Oz Owner's Manual for the MY06 - it's bloody hard to find this figure!!).
The rear suspension dropped to around 415 mm from wheel arch to wheel centre (from 425 mm). Spec is 440 mm +12/-24, i.e. from 426 to 452 mm (no trailer attached ... ). I expect that just fitting the tow bar assembly pulls the rear of the car down a bit. It does weigh rather a lot!
After a brief run down to Rickett's Point, I measured again - still 415 mm.
I took the two 10L fuel Jerry cans out of the front tool box and put them right at the back of the trailer bed. Removed some very light weight packing to the front of the trailer to make room for them. They weigh 10 Kgs each (full). I bounced the tow hitch with my full weight to get it to settle, and measured again - 415 mm.
IOW, the weight distribution in the trailer is all but irrelevant with the new rear springs/struts fitted to Roo2. This is an enormous improvement IMO.
When I got home, I measured again at the curb side with the trailer connected. Still 415 mm (both sides).
Took the trailer off and measured again. Now 425 mm (
before the new springs/struts were fitted, this measurement was only 400 mm, well under spec of 440 mm +12/-24 mms).
Weighed the ball weight of the trailer (actually the jockey wheel, which will be slightly lighter than the ball weight, but easier and less dangerous for me).
With the two small Jerry cans at the rear of the trailer, the ball weight has now dropped to around 50 Kgs, well within spec for the ball weight for this car.
When the trailer is "properly" loaded, I expect the ball weight to drop to around 40 Kgs maximum.
A couple of comparative photos:
Two years ago with nothing in the trailer, no fuel or water Jerry cans, no tool box:
Last week with the stuffed rear springs (with loaded trailer):
With the new springs today (with loaded trailer):
Depending on how things go, there may be some 1" lift blocks in my future, but the above seems more than acceptable to me for the present. If I do go that way, I would probably put the blocks all round to preserve the car's attitude to the road, and leave the front springs/struts stock. An extra inch at the rear would give an unladen wheel arch to wheel centre measurement of 450 mm - i.e. still within normal spec of 440 mm +12/-24). I would expect this measurement with the trailer attached to be 440 mm - i.e. exactly specified height for a standard Forester.
Far from feeling harsher or firmer, the car now seems better connected with the road than ever, even before the rear suspension effectively collapsed. There is slightly more body roll. I put this down to the fact that there was no component able to roll with the stuffed springs ...
:lol:.
New and old spring/strut assemblies are exactly the same unladen length - 715 mm. The new ones have seven complete coils, the old OEM ones had six complete coils.
:ebiggrin:.
