Making Predator Shocks Fit The Z

[CFM-Z440]

I have acquired a set of Fox podium shocks from the front of a 05 TLD preddy. I am trying to make them fit my Z400. The first attempt went bad. Shortened them by using spacers on the shock rod. Not well thought out...

Here is the new plan, First I am going to take the spacers out, then I am going to shorten the body of the shock...

Here is how:

The preddy fronts are 17-7/8" long when extended
and 13-1/4" fully compressed. That makes 4-5/8" of travel

The Z 400 fronts are 16-7/8" long extended 12-1/2" fully compressed. That makes 4-3/8" of travel.

So in theory, the Preddy shock could replace the Z shock if shortened by about an inch, or about 7/8" to split the difference with the extra travel. I'm thinking I will go a full inch though because the Z sits plenty tall as it is.

I can shorten the body of the Preddy shock without affecting anything else. There appears to be plenty of room. So far so good. The Z springs even fit the preddy shocks!

Now for the questions He He

I am going to be using them with +2 (st) arms, and right now they are mounted with stock arms and they feel soft and quite fast. Where do I need to start to re valve them? I have never been involved in valving.

I have a buddy that re valves snowmobile shocks, and he is willing to help. I am trying to learn so I can make changes as I feel the need to, and I want to know what I am doing.

Any advice or tech articles or what ever would be a great help to me!!
Thanks in advance
Chuck

[NormalZ]

Hit ya up on The Edge, brother...

[flynbryan]

Well, though I am far away from a suspension expert I have had a Predator in the past and I can tell ya this. The pred is probably atleast a good inch if not more wider than the Z. Also, it is certainly a good 40lbs heavier than the Z. So, I would be willing to be that you may actually be closer in valving than you think even with going to +2 a-arms.

I rode my buddy's 05' SE Predator about a month ago and it does feel very soft when just pushing on the bumper or sitting on it. But, the valving must really kick in when riding it. I never once bottomed it out on the mx track and it felt very cushy over the chop. I would shorten up the shock body like you've said, and then just try it out. May be pretty darn good as it stands.

[PMSracer]

sold my pred shocks to get works tripple rates with rezzies...

[CFM-Z440]

Well, I got er done!

First I called Precision Concepts to make sure it was possible. Big thanks to them, and NormalZ for getting me their number!

I ended up having 7/8" cut off of the body (by a machinist, Do NOT think you can just cut them off with a hacksaw!), and putting them back together. There was a mis calculation early on, and that was the reason for cutting 7/8" instead of 1 in.

I ended up with the same exact length as the stock Z shock, and it compresses 1/8" farther than the stock Z shock.

Here are some pics

This is the end that got cut off. You can see the lip that is there for the o-ring to seal against. This needs to be duplicated with you cut.


Here it is all apart. I was sizing things up, and as you can see, there is plenty of room to cut some off.


Once cut, and after a good cleaning, I put the tops back on, and started putting them back together. The hardest part is getting all and I mean ALL of the air out.


Here you see the floating piston aka "ifp" if your up on your shock lingo LOL The piston also has an allen head plug used for bleeding air bubles, and setting the floating piston height which is very important to get right!!! The predy shock is set at 2.75" for referencel


There is a proper tool for this that I dont have, so this is how I set the floating piston depth


Obviously, this cap is removable, but what I was trying to show here is the plug. This is used to bleed air also. You open it, and push down on the floating piston, and it pushes the air bubbles out. There is a check ball under that plug! so account for it before pushing anything through! I lost one, but lucky for me, Arctic Cat uses the same one in the one way valves for their oil injection on the sleds.


There is a special tool for this, but this works also... I pushed the cap in a long way, then put the retainer in, inserted the needle, and then slowly raised the pressure untill the cap bottomed on the retainer, then cranked the pressure up to 200 psi which must be the standard for Fox.


Here is our old nitrogen tank. This thing has been charging shocks since I was a child! LOL


There you have it!


BTW you also have to modify the bushings on the top end of the shock to fit in the Z frame.






I will probably do an actual write up on this when I get time

[NormalZ]

Hell yeah, buddy!!! That kicks ass, Chuck!!!

[madstuka]

I have a set of predator shocks I would like to use. Can you give me a cost estimate of what it will take to get them worked?

[CFM-Z440]

QUOTE (madstuka @ Mar 17 2007, 03:35 AM)

I have a set of predator shocks I would like to use. Can you give me a cost estimate of what it will take to get them worked?[/b]

Do you mean for me to do it? Id be interested in doing something like that.

HMMM.... Well, first off, do they have ressies? I dont know what all would be different with the other style, but I dont think it would present a problem.

Are you planning on using them with stock or wider than stock arms? For stock a-arms, We could try 5wt oil instead of 10wt. Unless you want them stiff.

Well, the shock oil is about $16 a quart. 2 should definately do it, if it goes well, maybe just one...
Machining the bodys to the right size was about $30 which I found cheap! That guy rocks!

If the shocks need rebuilt, its not a problem, because I can get the parts and stuff, but that could change the price a little. Fox parts are pretty reasonable though.

I would say give me $100 plus parts, and I will do the work and send em right back. I will give you my cost on the parts also. I can most likely do it within a week of recieving them unless I need to get parts.

When you get them back they will be ready to bolt-on.

PM me if your interested, we can work out the details.

[CFM-Z440]

If anyone is interested in having this done, I am doing this for a small fee.
I machine them down to size, rebuild them, and re-charge them. I did madstuka's shocks for around $230. The price could end up a little higher or lower, but should stay close to that range. His would have been cheaper if I wouldnt have had to get some different shafts for them.

There are 2 types of predator front shocks, and both styles will work. In stock form they are too long and by the time you get a set from ebay or something, they will probably need a rebuild.

One type has a piggy back ressi, that is the type that I use. I use mine with +2" a-arms and thicker oil than stock. That works really well for me. These are the type that I would recomend because they have a compression adjustment and you can use the stock shafts if they are in good shape.


The other type has an internal floating piston (ifp). That is what madstuka has. I thought they were going to be too soft, but he loves them. I dont think he does much jumping though, so if you do, we may want to try 10wt oil in them. I put his origonal Kawi springs on them also which are a tad softer than the preddy springs. So there is another thing that you can try when it comes to tuning These are the type that will need new shafts every time.

The turn around time depends on a lot of things, but I should be able to have it all done in a week or 2. I still have all my specs from before, so as long as there are no unexpected supprises, it should go pretty smoothly.

Revalving is still a new art to me, so I would prefer to stay away from that for the most part, but if they end up too stiff or too soft, there are things I can do to change that as long as you dont mind shipping them back here again.

I think the ressi shocks were on the Troy lee edition preddys and the regular edition had the ifp shocks. Im a little cloudy on that though because I dont pay much attention to predators.

If anyone is interested, shoot me a PM

[madstuka]

Hey Chuck,

I bought some +2 A-arms and an axle. What would you suggest I do with the shocks now? Will the length be ok? Heavier oil? I'm going to Silver Lakes MI on the 5th of Oct, I'm not sure that I will have the time to send them out and get everything done.
I'd hate to come up short since I have not been able to ride lately. I may just wait until after the trip and have you build me some with rezzies.
By the way, I rode on Taylorville motocross track and was really getting some pretty big air with these shocks and I never bottomed out. I'm just worried that I will bottom out with the +2 A-arms. Pat

[CFM-Z440]

QUOTE (madstuka @ Sep 19 2007, 01:28 PM)

Hey Chuck,

I bought some +2 A-arms and an axle. What would you suggest I do with the shocks now? Will the length be ok? Heavier oil? I'm going to Silver Lakes MI on the 5th of Oct, I'm not sure that I will have the time to send them out and get everything done.
I'd hate to come up short since I have not been able to ride lately. I may just wait until after the trip and have you build me some with rezzies.
By the way, I rode on Taylorville motocross track and was really getting some pretty big air with these shocks and I never bottomed out. I'm just worried that I will bottom out with the +2 A-arms. Pat[/b]

Crap, this has been up for a while and I missed it...


Pat, I replied to your email about this, but never heard back.

That's great news that the shocks have been working good for you. I would be happy to build you some with rezzies! I can probably do it cheaper than last time.

Let me know when your ready

[camaro1976]

so i'd have to find shocks, ship them to you, and it would cost up to $200 more to modify them to fit? the springs are single rate right?, because i could get works dual-rate conversion springs for them then.

the cheapest foxes w/ rezzies i could find on ebay were $250 with 1 1/2 days left. the dual-rates w/o rezzies were going for $50 without any bids and 1 1/2 days left.

let me know how much you think it would be total because it might be cheaper for me in the long run just to get some works, or maybe some cheap elkas on here.

[CFM-Z440]

QUOTE (Camaro1976 @ Dec 10 2007, 11:28 PM)

so i'd have to find shocks, ship them to you, and it would cost up to $200 more to modify them to fit? the springs are single rate right?, because i could get works dual-rate conversion springs for them then.

the cheapest foxes w/ rezzies i could find on ebay were $250 with 1 1/2 days left. the dual-rates w/o rezzies were going for $50 without any bids and 1 1/2 days left.

let me know how much you think it would be total because it might be cheaper for me in the long run just to get some works, or maybe some cheap elkas on here.[/b]

Odds are most used shocks you find will need a rebuild anyway. The aftermarket (fox included) shocks dont hold up as long as the stock Kayaba's. So, no matter what you get, count on having to have them rebuilt. Usuallly by the time someone sells them, there is a reason. madstuka bought his pretty cheap on ebay, but they were shot. The oil was full of nitrogen and one was worse than the other.

It actually cost more to mod the non rezzi version because I had to use a different length shock rod. The main body on both types had to be shortened on a lathe and the upper mount had to be shaved.

The springs are what ever you want to use. I am using the stock predator springs on mine, I have used the LTZ springs in the past. They are both a little soft for my setup, but I am running +2 arms.

madstuka used his stock KFX springs with the non rezzi version on stock arms. I didnt get much of a chance to ride test them, because they were very soft with my +2 a-arms, but he really liked the way they turned out.


Not going to BS anybody here... Im certain that Elka's or Works shocks are going to be a better ride (Not that I can complain about mine) but These are going to be fresh and in good conditon which will ride far better than a pair of the others that are used and need a rebuild.

[camaro1976]

well if you find a cheap set of pred shocks, you know who to call!

[jmax]

okay so heres a stupid questin but i'll ask it anyway, could you not just modify the z400 frame or a-arm to compensate for the 1 inch longer travel, keeping the stock travel of the fox shoxks the same giving you more suspension travel?