Hello everyone,
Can anyone give me a resource that explains what the shock adjustments on the Z Force 800 Trail do?  I'm not very familiar with what rebound, pre load, etc all mean.  I didn't know if there was some type of a quick reference guide somewhere on here.  I bought it used and do not have a manual. 

[2015 Z Force 800 53/Trail EPS]

Hello everyone,
Can anyone give me a resource that explains what the shock adjustments on the Z Force 800 Trail do?  I'm not very familiar with what rebound, pre load, etc all mean.  I didn't know if there was some type of a quick reference guide somewhere on here.  I bought it used and do not have a manual. 

Well, as you know shocks compress then return back out. The compression and rebound adjustments effect this. Think of them like needle valves controlling fluid flow..which they are. A closed valve won't let fluid through and a wide open valve lets the most through. So..lets start with the Compression valve...the upper on on the front..the rear stocks don't have one. As the shock compresses it forces oil through that valve. If it's hard to get through, it compresses slowly making a stiffer ride but harder to bottom-out the shock. That one you may want about one or two clicks from wide open. All the way to the left then one or two clicks to the right unless you are having bottoming-out issues. Now lets talk about the rebound. Once the oil has passed through the compression valve it also passes through a check valve so it can't go back through that same valve. The oil that bypassed to the bottom end of the piston has to get out through the rebound valve..the one on the bottom. It will determine how fast the shock extends back out after being compressed. Too fast and it's a jolt and a springy effect. Too slow and it won't recover fast enough for the next bump. Everybody's likes differ. For me I like not having that jolt and like the feeling of landing like a cat on all four...or a little trophy-truck feel so I like it a little slower then then some others. That one I like to find the center of the range between wide open and closed and go two or three clicks to the slow side.

Preload- that's just setting the spring's preload to get the proper ride height for the average load you carry or the riding conditions. Ideally you want the suspension mid-travel to 60/40 and the front of the skid plate level to 1/2" lower then the rear of the skid plate. Although you will find that Elka has different specs.   

The Zforce trail models are set up stiff from the factory. Its a rough ride on the trails with the stock adjustments. On your rear shocks the only adjustment you have will be rebound at the bottom of the shock. On the fronts you have compression on top and rebound on the bottom.  If you notice there is labeled on the dials or each side of the dials the letters S (slow) and F (fast). There are several explanations on this site of how folks set up their shocks, but I set mine in this manner: turn the dials all the way to F, you will hear and feel clicking as you proceed. Then turn the rear shock dials 3-5 clicks back toward S. Turn the fronts top and bottom 4-6 clicks back toward S. Lower your Tire pressures to 7-8 psi fronts and 9-10 psi rears. All this will soften your ride. Hope this helps you understand how the dial adjustments  work.

What year?

It's difficult to get a smooth ride on a stock trail model.

I found replacing the springs the best way to improve the ride.

Thank you all for the insight!  The year is a 2018.  I bought it with 79 miles on it last fall from an older gentleman who said he had a bad back and couldn't sit in that position as it hurt his back.  He told me he had it on the softest settings, but it didn't help him.  My first couple miles with it were horrible.  I couldn't believe how stiff it was.  (Now that I know what I'm talking about) the front compression knobs were on the stiffest setting so I backed them off a bit and noticed quite a difference, so that's where I left it for the rest of the year.  I've always had my snowmobiles on the softest settings I can put them on without bottoming out constantly, but they are pretty easy to figure out.  I really wanted to understand what I was doing with this type of shock package before I start messing with them.  Looking for as soft as I can get with this package, and now I can start playing.  Maybe shock upgrades in the future, but now this year.  I'll be adding wheel spacers as soon as I do more research and find out what works best for people.  Having forums to research and ask for help on is fantastic!  I really appreciate you all for the help.

The cheap fix:

Set of 4 replacement springs ....

Best $170 you will ever spend.

https://www.banditutvsuspension.com/product-page/cf-moto-z-force-800-trail-rear-springs

[2015 Z Force 800 53/Trail EPS]

The cheap fix:

Set of 4 replacement springs ....

Best $170 you will ever spend.

https://www.banditutvsuspension.com/product-page/cf-moto-z-force-800-trail-rear-springs

Yes..and I just happen to have a new set of Bandit front springs I'll let go for 50 bucks plus shipping. That means you just need a rear set.

Where are you located NMK?

I should probably ask how hard are they to change out?

Not hard.

I used a couple of ratchet straps to compress the springs. A bit fiddly but it worked.

Takes about 15 minutes a shock (once they are out) to swap the springs.

The fronts are a little more work than the rears. It's the rear that is providing the stiff ride.

Lots of youtube videos.  Here is an example: https://www.youtube.com/watch?v=LES7YJ5hYxo

[2015 Z Force 800 53/Trail EPS]

I should probably ask how hard are they to change out?

I am in Albuquerque New Mexico. Zip is 87109. The fronts are a little harder to change out then the rears. Just have to compress the spring about 1.5"s. Can do that with some straps or a spring compressor. I made one by loosely coping and HL compressor.

One thing I just thought of is if these increase height it won't fit into my trailer.  I have to take my roof of to get it in now...

[2015 Z Force 800 53/Trail EPS]

One thing I just thought of is if these increase height it won't fit into my trailer.  I have to take my roof of to get it in now...

They don't...unless you crank-up the preload. The springs were designed to replace the OEMs and give a better single-stage ride.

Awesome. I really didn't want to buy a new trailer.

Rather than unbolting the roof I'd air the back tires down and then re inflate to the desired pressure once I get there and unload.
It's close for me but it squeaks in and out without touching.