% up travel/down travel

[jgbjgb]

I have a mini buggy and the consensus with mini buggy builders is 1/3 sag with passenger/s sitting in the buggy. That relates to 1/3 down and 2/3 up travel.

Does this carry over to truck LT suspensions?
Is there a recommended %, 1/2 up/down, 1/3 up/2/3 down, 2/3 up/1/3 down, etc?

Or is there recommended percentages depending on type of terrain and speed, slow speed versus higher speeds, whoops versus rocks and ruts?

[RCJoslin]

I've heard 70/30 is a good ratio....

[jgbjgb]

Is that 70 up/30 down?

or

Is that 70 down/30 up?

[1450-ranger]

How much travel do you want total?
How high do you want your vehicle to sit at static ride height?

[jgbjgb]

I should get 15-16" travel in the front.
I should get 16-18" travel in the rear.

Ride height I have no idea unless you mean lift over stock. That would be 4-6" front, I am assuming 5", and rear I want to keep level with the front with my two spares in the back. (see my thread: Deaver spring question)

I imagine this will be about the time everyone starts groaning and saying "what an idiot".......oh well.

[1450-ranger]

Not at all. Get the most up travel you can with a moderate ride height. Some guys like their vehicle's lower or higher. This effects up/down travel ratios. I like a truck with more up travel, so it sits a bit higher. On most vehicles you are constrained where bump is at, so work from there.

[jgbjgb]

I found this article, I did find the natural frequency section interesting, scroll about half way down the page.

Is this article true or just BS?

http://64.233.167.104/search?q=cache:Y2My9rSI-csJ:www.autospeed.com/cms/A_108167/article.html+static+ride+height&hl=en&ct=clnk&cd=19&gl=us

[1450-ranger]

To a certain point, yes. Dont get hung up on it.

[steveG]

Jim, I feel like I'm crashing all your threads... hopefully the info I'm giving is useful.:D

All my beamed/leaf sprung trucks have had around 10" of bump travel (front and rear) and have worked really well. I just measured the rear of my Bronco and it's got 10.5" of bump travel measured at static ride-height. I've never measured the front but it's similar.

If possible I like for the rear to have more bump travel to reduce the likelihood of the rear bucking because it ran out of travel.

[1450-ranger]

Our truck is set up as follows

Front
12" up, 20" total

Back
17.5" up, 28 total

[RCJoslin]

yeah 70% up 30% down..... But what do I know?

[scottm]

a lot of tt's run thier ride hight real low, 1/3 up, 2/3 down. Im sure its to lower the center of gravity for high speed, but it seems like a bad idea for other reasons - riding around in the last section of the bypass will give a harsh ride, plus there is less travel to absorb a big hit. Dirt bikes have the best suspension in the world, imo, and they are set up typically with 4 inches out of 12 at ride height (1/3 down, 2/3 up). Some tt's are known to kick up in the back, and some people think that means it needs more rebound damping. I disagree. I think the kicking is caused by bottoming out in the back, which is helped by both the low ride height and by excessive rebound damping, which causes it to pack up. I havent driven an off road truck yet, but I have been tuning dirt bike suspension for 10 years, and I think the setup should be similar. I will test my theories on my own truck within a year...

[jgbjgb]

Jim, I feel like I'm crashing all your threads... hopefully the info I'm giving is useful.:D

All info is useful, it is the sifting through and understanding it......

--------------------------------------------------------------------------------

OK, so to bring everything together:

1497 is running more than half up travel but not quite 2/3 up travel.

Camburg says I should get anywhere between 15-16" front travel
We mount the front set up, cycle the suspension for correct shock placement and set the ride height/ up, down travel ratios by using the collars on the shock.

With the through the bed shocks and Deaver springs in the rear I should get between 16-18" of travel.

Now this where it gets sticky......

I have my front ride height, I would like to have my rear ride height the same. This would be my STATIC ride height (with my two spares mounted)

I call Deaver and give them the following info:

Amount of total travel
Amount of up/down travel, say I want 10" up.
Weight of rear of truck (with my two spares)


So, when we mount the rear springs and set the truck down on the floor, the springs should sag 10" for my 10" up travel, be level with the front, and give me 6-8" down travel.

Am I correct or did I miss something?

[jgbjgb]

I have my front ride height, I would like to have my rear ride height the same. This would be my STATIC ride height (with my two spares mounted)

I call Deaver and give them the following info:

Amount of total travel
Amount of up/down travel, say I want 10" up.
Weight of rear of truck (with my two spares)


So, when we mount the rear springs and set the truck down on the floor, the springs should sag 10" for my 10" up travel, be level with the front, and give me 6-8" down travel.

Am I correct or did I miss something?

I made a mistake in the above post. I got the up and down travel backwards.

I call Deaver and give the following info:

Amount of travel
Amount of up/down travel, say I want 10" up
Weight of rear of truck (with my two spares)
ride height/lift

So, when we mount the rear springs and set the truck down on the floor, the springs should sag about 7" for my 7" down travel, be level with the front, and leave me 10" for my up travel.

Am I correct or did I miss something this second time around?