continued setup from before:

Ok last thing we did was get the height of each spring with no crossovers in and at ride height with the rider on. Take note at this time to see if it feels softer than it did before. The crossovers could have been transfering too early before making it stiffer. Now you need to understand how to use the intermediate springs and crossovers to adjust the firmness.
Compare each of the middle springs, not the main or zps, RIDE HEIGHT LENGTH that you recorded to the Extended Length you recorded earlier. What is the percentage of the spring length when compressed? To find out divide the Ride Height Length by the Extended length. For example if the ride height length was 2.5 inches and the extended was 3 inches then 2.5/3=83%.
Now if you have a spring that hardly compressed it is most likely too stiff for the last spring before the zps. If it has three springs in addition to the zps then the second spring (on top of the main spring) should be a higher percentage than the third spring, unless the shock uses the same spring for both. The lower the percentage the softer the sock will be in the beginning. I have ran tender springs that sat at 70% before. Of course the only spring fully collapsed should be the zps.

Next you need to know the collapsed length of the tender springs. I should have told you to get this earlier when we had them them all off but I forgot. To get this you can put them in a press or a vice between two pieces of flat steel and compress them to just before coil bind. Measure the distance between the two peices of steel and record as COLLAPSED LENGTH of each spring.

Now lets look at what can be done for any given set of tender springs. Now that you know the collapsed length of the springs, the softest you can make it is to set the crossovers for each spring so that the distance between the spring seats is the same as the collapsed length of that spring. Setting all tender springs like this will yeild the softest ride possible for the springs you have. now keep in mind that this setup will transfer to the main spring later in the stroke, and the main spring will bottom a little easier. Now you have the difference between the Ride Height Length of each spring and the collapsed length to play with. Of course if you set the crossover stack to the Ride Height Length you have removed that spring from working. Basically the closer to the ride height length the crossover is the sooner the transfer and the firmer the ride. The closer to the collapsed length the crossover is the later the transfer and the softer the ride.

If you set it up with the shortest (collapsed length) crossovers and it is still too stiff for you, you must change to softer springs. If you have room above the preload nut to go up then you can use longer tender springs. This will give you more of the shocks stroke to use for the tender springs before transfer to the main happens. It is good if you can determine how much of the stroke you can use for the tender springs and still have enough for the main to do its job and to not have too much roll in the corners. I will try to come up with some ball park figures on some of these measurements to help you get a starting point.

In the case where two springs just alike are stacked together you have to remember that the two together are only half the rate of one of them. If they are both 100 lb springs for example, placing a 100 lbs on top of them will compress each one 1 inch for a total of 2 inches. This is twice the distance that just one spring will move with 100 lbs on it. Remember this when setting the crossover stack. If one spring has a taller crossover, (and it should in most setups with two like springs) then it will transfer first and when it does the rate of the springs will double, (it will get stiffer).

out of time again, more later.

 

Sorry if I was confusing earlier, but I know that this can get a little complex.

There are people who do rebuild the rear stk shock to include a ssd (elka) and zps (pep) spring but unless you find one that does this affordably etc its a better decision to just go for the aftermarket rear shock as it normally has more travel and performs better than the rebuild with zps or ssd.


I know the prices are higher now but when I was making my comparisons the elka rear was 650.00 and the rebuild with ssd was from 250.00- 550.00. My decision was based more on performance and knowing the rear needed help more than the expense etc, but if I had been on the fence and my source was anyware near 400.00 or more than it would have been a no brainer decision.

 

Crow you are limited on the stockers and the fronts are the biggest problem. You can adjust the preload on the fronts and though it may help thats all you can do. There not rebuildable and have no comp or reb adjustment. If your bottoming the fronts a lot try turning the bottom of the shock to a higher position on the little snub or notch etc and see if that helps any.

The other thing that may help on larger jumps is landing better and that will prob do more than the adjustment [img]i/expressions/face-icon-small-smile.gif[/img]

IF the rear is the problem you have both comp, rebound and preload to work with that can help the general ride quality as well as be set to resist bottoming more. Plus the rear is rebuildable and you can have the rebuilder make changes to the valving and even the spring rates (need new springs etc) and can get pretty good results. I had this done to mine before changing to the elkas and it did perform much better than before but the fronts were still a weak link.

hope that helps you save your frame and but from damage.

 

thanx a lot man. i knew that the front only has preload adjustable, but i didn't realize that the rear was fully adjustable like that. do you have any idea how much it would cost to rebuild a rear shock? also, when i'm bottoming the fronts i realized that it was usually because i was landing wrong, but there's a lot of times where i land pretty much perfectly, and i bottom all the way around, i have a picture of me landind like this at pismo one time, and my nerf bars are literally in the sand. if i had a scanner i'd post it to show u. thanx again for the help.

 

today i was lookin at my rear shock, and i think i might have found the compression and rebound adjusters, but i'm not sure. i checked my repair manual, and it was no help. how do i adjust the shock? also, what does adjusting the compression do?

 

First I appologize for not replying sooner but I had completely missed your reply earlier etc. and just saw it now.

I think this is the area that I may be having the problem since as I stated earlier the front just needs too much preload to get the ride height anyware near balanced to the rear. This relationship of the crossovers, secondary springs is what I suspect (set up with a later transfer for the main spring etc) you have just nailed my problem.

There is a lot of things to be measured and tested and I want to get started ASAP, but I have another project currently working and its in the space I need to work on the quad. So I hope to be starting soon but will not have any additional input as far as the measurements go for a little longer.

I hope to be doing some engine work and pc the frame as well so there will be plenty of time to get 100% into this once I get it started, so hang in there and dont bail out on me or the rest of the members etc.

Thanks a lot for all you input and help.

 

Your bottoming out can just be from over jumping the capabilities of the stock suspension. If your hitting and decent sized dunes and "flat landing" (all four tires at once while dropping straight down etc) the stk set up is not going to cut it unless your an extremely light rider.

The compression adj should be accessed on the side of the "can" and the rebound on the bottom of the shock, but it has been a while since I even touched one of the stockers so this may not be 100% accurate.

Remember that adding compression (turning to the right or clockwise) will have more of an effect on the smaller stuff than the bottoming resistance, and you can read up on more about this on the many links listed earlier (I suggest everyone does this since there is a lot of info to be had) and the rebound has little effect on comp at all but it will allow you to make the overall ride a lot smoother. Think of it as the rear tire has to return to the extended length before it can be ready for the next bump etc. and the right amount of reb makes worlds of difference.

Also dont be afraid to increase the preload as this will also help on bottoming resistance. MX-Tech has several different set up guidlines for dirt, sand and arena etc and most everyone agrees that sand riding will require additional comp and rebound.

 

I just got some PEP ZPS for my R and I have some questions. The rear one was used and in perfect shape so I installed it. The fronts where sent to Derisi for revalving.

1. Since the the ZPS sit with the helper spring completely collapsed do I have a have less upward wheel travel when the bike is set up to ride really low? I know it gets it travel back once the suspension stretches out.

2. Is it normal to hear the helper spring collapse when I pick the back of the quad off the ground and drop it. It's not very loud but my stock shock did make that noise.

3. On the PEP rear ZPS shock where do I adjust the rebound?

4. Does lowering the front affect the toe of the front tires?

thanks

 

1. Your total travel is the same, but yes there is less up travel if you measure it from ride height. There is more down travel if you measure from ride height however. Since the total travel is still there you are in good shape and the lower ride height is a big plus for handling.

2.There will be a noise when the crossover is hit from the zps spring collapsing.

3. rebound adjustment should be at the bottom of the shock.

4.Not significantly but because atvs have some toe change through the travel (bump steer) it will change some. I would reset my toe at ride height with rider on if you lower the frt. It is not a good idea to lower the frt without lowering the rear to match because that will change the caster on the frt.

 

Thank you for the fast reply. I haven't taken it out for a spin yet because I haven't gotten the front shocks back but I guessing it will be a big improvement from my previous setup (Works triple rate a-t steelers w/o rezzies and stock rear).

Now, on the rebound adjustment, which way speeds it up and which way slows it down. You are talking about the rubber ball looking thing under the main spring right?

Something else I have been thinking about, with little or no preload on the shocks what causes the suspension to kick out over a set of whoops better than a preloaded shock?