[shep]

i want to build a light weight camping trailer with independent suspension
i am just going to copy the suspension bits off my wrinklies camper. how do i work out what coil spring rates i need?

[TASSIETOYUKI]

I don't know how you are supposed to do it, but... I am building an off road caravan at the moment with a coil sprung beam axle. (independent got to hard for the weight i wanted, oh and i was to lazy to get the dimensions correct for what i wanted ) So what i did was to work out what weight i expected it to be then trolled the net to find an off road vehicle with about the correct weight over the axle. I also took into consideration the availability of parts to suit said vehicle. I am using front 80/100 series coils and shock with poogero rear control arms and adjustable front pootrol pan-hard rod. Through ARB they can give you the spring rate and free cambers of both theirs and standard springs. I set my bump-stop and shock heights to what i wanted and will be fitting the coils at a later date. If it sits to low there is many aftermarket spring heights to get me sitting at the correct ride height. Look forward to seeing more of this...

[shep]

i have been thinking vitara springs and if they are no good then visit the wreckers. the all up weight i am aiming for is 350kg including the
tent top and boat rack which is the reason that i want the independent suspension.

[TASSIETOYUKI]

Just remember most 4wd's are heavier in the front than the rear, hence my landcruiser front stuff

[shep]

lol thats why i was planing on using vit rears.

[brendan]

not having a clue on spring rates ect i would say vit rears would be a good start. Based on common sence

[tanshi]

maybe even jimny or coily rears

[Saam]

NO coily and jimny rears are so freakin soft lol no weight holding capabilities at all really

[shep]

Saam wrote:

NO coily and jimny rears are so freakin soft lol no weight holding capabilities at all really

they only need to hold up around 150kg each

[Saam]

ive got some vit front and rear springs here, and i think i might have some coily rears aswell.

[TASSIETOYUKI]

Just out of interest the 80/100 series standard front spring is rated at 160 Lbs per Inch. So on your trailer these springs would squash down 53mm (approx.) from there free height...

[hutch]

shep wrote:

all up weight i am aiming for is 350kg including the
tent top and boat rack

I built a fairly standard 6x4 box trailer with 4 jerry can holders on the sides and it weighed in at 300kg empty.

[shep]

this 7x4 is 220kg with out the boat

[woody1]

TASSIETOYUKI wrote:

Just out of interest the 80/100 series standard front spring is rated at 160 Lbs per Inch. So on your trailer these springs would squash down 53mm (approx.) from there free height...

I agree with Tassie.
But why independent?

[shep]

independent because there is no leaf springs or a long solid axle and i want to keep
the weight down. also if you get the chance, follow a well set up trailer with independent suspension in the bush. nice soft flexible suspension
equals less breakages.
the amount of supposedly heavy duty bush trailers that we see with broken components here is amazing and i would like to try a few things out.
in a $50k camper they still mostly use the same old components that still fail
on our roads.

[woody1]

Now i understand your logic, but wont the springs sag after a while without maybe some struts.
The boxy will go anywhere though ah.

[shep]

these springs have supported a 1400kg trailer for over 3 years and was originally a prototype for the current off road campers from cub campers.
coil springs don't need struts however i will be running shockies.