shock, stroke, postion and suspension questions (for sierra)

[SiKiD_01]

ok, maybe its been asked before, but mainly people talk about the shock mounting positions.

my question is: where, on the stroke of the shock, should its shaft sit when on level ground and at nrmal ride height (as in, when parked on you driveway)

is it more desirable to have more down travel, or up travel from the middle of the shock?

ok, example: i have a shock, compressed, its 300mm, or 12", and extended, 600mm, or 24". now half way, it would be 18", 6" up and 6" down. would this be a good set up, or would it need to have more up travel, or down travel?

the reason why i'm asking, is if its got a lot of down travel, it would be very easy for the shock to bottom out on dips and pot holes etc. when being compressed quickly and hard. but then if its got more up travel, the shock may tend to top out and over extend, and maybe get pulled apart.

i understand that you can/should use bumpstops to limit up travel, and usually a shock is used to limit down travel.

my mate and i are building a sierra swb up, and have finished RUF, with chassis extension, and now we are sort of trying to figure out how to mount the shocks. i know shocks can be done at the very end, as the sierra is not yet rolling on its own. (still need to put together the back diff and hang it.

we are planning on rolling it out of the shed, and using the fork lift to flex it up front and rear to see if anything is binding, hitting, or limiting, and then we plan to measure the total travel we are getting, and then to find a shock to match.

on the rear, we are planning to inboard the shocks for the upper, but still unsure on how or where to mount for the lower mount. on the front, we are looking at putting some shock hoops in, and make some mounts for the lower on the diff.

so if anyone can help us out, or even better, some pics, and maybe some measurements, that would be really good.

is there any rule for the height of a shock hoop on the front? or can it just be anything? what have other people done?

thanks for any help
Steve

here are a couple of pics of how the sierra is now.

[germo]

thats not the ride height is it? its going to sit alot lower after the bricks are out?

just get your car and lift the wheel up with the fork or what ever, and get the wheel as compressed as you can, then measure the distance from the top of your mount, to the mount on your diff, then make the shockie 1 inch shorter than this. ie at full comp, you will only have 1 inch of shaft showing, so at "driveway height" it will sit where it sits and it will drop as far as your suspension/shockie will let it.

you can't have the shockie any longer because it will bottom out on full compression, the extra inch is just a safety thing, make it half an inch if you want.

otherwise you are just wasting useable shockie. your suspension can only go up a certain amount, no need to have 3 inches of shaft showing on full compression!

I have got 36" shockies in the front, with about six inches or so showing when its level and about half an inch when fully compressed. and the rest goes down when the wheel heads down!

I've got 15 inch shocks on the back mounted / \ about 3 inches showing level, but I might need to adjust as I think its bottoming out the shockie.

hope this helps
if there is other methods of this I'm open to them, but that one is a winner!

enjoy ashley

[sierrajim]

and usually a shock is used to limit down travel

Huh??????

no, the binding of suspension bushes and maximum extension of the springs limit down travel.

If you're using your shocks to limit down travel you'll most likely rip the eyes straight off the ends of the shocks.

Here's a picture of the shock setup on the rear of my hilux for some ideas. (note, these shocks have now been swapped out for shorter units they were too long and were very close to bottoming out. )

[germo]

sierrajim you like your red boots.

but what is the one on your track bar?
does it protect a rod end or similar?

or do you have a slip thingy is there to allow you bar to shorten when your suspension is compressed? but still stop axle wrap.

just curious, because I have a solid bar in the rear of my sierra and I'm not sure if it is making the ride harsher than normal, due to the fact that it may be limiting the up travel on bump. although I do have a shackle in there.

sorry for hyjacking thread, but Author SiKiD_01 hasn't replied so he won't mind!

enjoy ashley

[redzook]

sierrajim you like your red boots.

but what is the one on your track bar?
does it protect a rod end or similar?

or do you have a slip thingy is there to allow you bar to shorten when your suspension is compressed? but still stop axle wrap.

just curious, because I have a solid bar in the rear of my sierra and I'm not sure if it is making the ride harsher than normal, due to the fact that it may be limiting the up travel on bump. although I do have a shackle in there.

sorry for hyjacking thread, but Author SiKiD_01 hasn't replied so he won't mind!

enjoy ashley

if u have a shackle it shouldnt be binding
the slip in sierrajims one replaces the shackle

[germo]

yeah I thought that may be the case.
I have also changed the angle that the shackle was on and the angle of my bar so that the pinion doesn't flex up and hit it like it was doing, and bending it.

it seems to be working a bit better at the moment, have to street drive it to see.

enjoy ashley

[Stoo]

In a coil setup what limits drop? Surely that is the shock absorber?

Stoo

[ZOOK60]

In a coil setup what limits drop? Surely that is the shock absorber?

Stoo

i would say that the bushes would limit down travel in a factory coil setup
It would depend on whether it is a captive or non captive coilsetup too