expert x tuning

[cjgodden]

Ive been battleing the rear suspension like everyone else. At the end of last season I tried pulling the center shock out and as far as I'm concerned it sucked even worse. I think it even exagerated the problem. My issue is I can get the suspension to be good in the small bumps and rige good, but at this setting big bumps it is too soft. When I adjust so that it can handle the big stuff it is way too stiff in the stutter bumps. After removing the center shock it seemed to sack out even quicker than with the shock there.

So my thinking is that we have been going the wrong way. it seems that the center shock is doing more than effecting front skid pressure the way a normal sled suspension does.

So I have came up with two ways to try, what do you guys think.

1. loosen the upright shocks to be where I like them in the stutter bumps and stiffen the hell out of the center shock. as it seems the center shock is effecting the lower end of the travel and this may hepl the sacking out.

2. uncouple the suspension by repositioning the center shock, I had this thought on the drive home tonight. What if I were to take the center shock and attach one point to the skid and the other the the shaft that the limiter straps attach. Or better yet make a front swingarm and and attach that to the chassis and the skid and the center shock to the skid and the swingarm. then the suspension would act like a normal skid and then I would be able to tune it.

option 2 is a little more in depth but I don't think it would not be that hard. there has to be a solution out there. I tired of getting my teeth jarred out and valving is not working and I'm not so certian that a dual rate spring system will work either.

Opinions?

 

[TLKDPROD]

I had Cycle Improvements in Waterloo,ON to provide me some custom wound MX-Tech progressive rate spring back in september. I went for 280-400lbs spring for both of my rear shock. (stock is 280) I'm hoping it to be better.

That cost me waaaay too much... but it can't be worst than stock though. Just by throwing a leg over it and my general feeling, The first 25% is pretty much the same as the stock 280s, then it gets stiffer.

I also got a 100-200 spring for the forward shock that I'm still questionning if i'll be using it...

Still didn't ride it... So can't tell if it solves the problem...

 

[cjgodden]

Thats my point tlkd, I'm scared I'm gonna throw a bunch of money at springs on the upright shocks and not fix the problem. My upright springs are 355 ( I just had them rated). I have an 04, and I know the 05 have a different rate spring and i believe so do the 07's. I'm beginning to believe that even ADB can't even tell you how to tune there own suspension. Has anyone tried to stiffen up the center spring?

 

[snowhawk jockey]

Thats my point tlkd, I'm scared I'm gonna throw a bunch of money at springs on the upright shocks and not fix the problem. My upright springs are 355 ( I just had them rated). I have an 04, and I know the 05 have a different rate spring and i believe so do the 07's. I'm beginning to believe that even ADB can't even tell you how to tune there own suspension. Has anyone tried to stiffen up the center spring?

Not to hamper innovation, but...

The springs and the shim stack MUST be changed on any '04 to get ANY love out of that setup. PERIOD. If you want to, after the shims and springs are changed, you can add compression adjustable remote resevoirs(sp) to the upright shocks.
Your #2 idea to rework the rear "linkage" to scissor arms is one way to hurt your chances of actually getting it to work right. It (the '04) was fuuked when it was designed and it was fuuked when it was mfg'ed. The '05 specs improved the situation. It should be only one shim in the stack, plus springs...

The idea to use progressive springs is a good one.

 

[TLKDPROD]

I'm beginning to believe that even ADB can't even tell you how to tune there own suspension. ?

They haven't done fack all developpment for the backcountry & big jumping ! Trail riding was their stuff and targeted market for all liquid S-H before '08 because they're in QC and that's the only thing you can do in Qc: fackn trail riding ! You can consider yourself lucky if you can find a field with 14" of fresh heavy-a$$ wet snow and that the farmer who owns the land don't call the cops because you're "destroying" his field. One thing's for sure is that on a Quebec groomed trail, the setup rocks ! But too soft for anything else out there... plus most of us are ex-MX racers who can handle rough sections so... The 503 setup was great in really rough stuff though, I remember that... Wish I took the springs off mine and throw them on my 8... Suspension design was different as well...

According to the Manual, the 503 springs are rated at 185-460 !!! (juuuuuust checked on ADB's site) So damn... that's a progressive thing & the end is pretty damn stiff ! I hope mines won't be too far off...

I contacted ELKA suspension in Quebec (www.elkasuspension.com) and asked the service guy there if they could provide me some custom made shocks... He said if you can get a qty of 5-6 we'll build some for you... I sent him the CAD drawing that I made of the S-H shock... And it would end up costing the same price as Quad front A-Arm shocks so around 1200$ buck... That was too much & anyway couldn't find 2 other people to have the minimum order... so I decided to stick with the progressive stifer springs.

 

[buffaloHAWK]

so it sounds like the 503 springs are the hot set up....soft in the begiining and stiff at the end. should i put my 503 springs on my 600 rear suspension?

 

[buffaloHAWK]

why why why???

so why did ADB go to a stright rate spring insted of the progressive rate springs that were used on the 1st 503 hawks?im really confused....wouldnt those 185/460 springs work best on all expert rear suspensions???

 

[TLKDPROD]

The 503s were initially a Snocross style developped machine. Was very great at it but not enough "uncle, trail riding friendly" attitude for the Qc grommed trail. So they went softer, not progressive as a cost issue I think...

And again, the setup is great for trails but who rides trail with Hawks anymore ? 95% of the guys I know, even in Qc, ride backcountry, power lines, lakes & large open area where they can find good snow...

IMHO, the end of these springs were A BIT Stiff, If I had to reorder custom progressive springs, and know what the 503s were, I would probably go for a finish like 430-440 lbs... But can't tell, I'll try mines and let you know.

 

[buffaloHAWK]

well i have the 600 rear suspension on my 503 and im gonna leave the stock springs on until the trails actually open and they get rough, then ill play with my stock 503 springs if need be. the problem i have with the 503 is that is bottoms very easy on big bumps, we have even changed the valving to stiffen them up but still didnt do enough. i am wondering how the 600 were so stiff with softer spring rates compared to the 503...you got any snow there to test your progressive springs on a packed trail?

 

[TLKDPROD]

well i have the 600 rear suspension on my 503 and im gonna leave the stock springs on until the trails actually open and they get rough, then ill play with my stock 503 springs if need be. the problem i have with the 503 is that is bottoms very easy on big bumps, we have even changed the valving to stiffen them up but still didnt do enough. i am wondering how the 600 were so stiff with softer spring rates compared to the 503...you got any snow there to test your progressive springs on a packed trail?

Your 503 suspension bottomed out pretty easy ? Really ? How heavy are you ? I'm 165 and just couldn't bottom it out on 4 feet bumps (4' high whoops section actually) almost wide open. And on my 800 I just hit the gas and it almost bottoms out... It feels like there's a hinge in the middle of the Hawk.

I have snow here around Prince George since like 3 days but i'm waiting on a set of piston & ring... Mine showed big amount of wear... they'll come mid next week. Next week end going back & forth to QC... First ride will be december 6th...

 

[cjgodden]

Not to hamper innovation, but...

The springs and the shim stack MUST be changed on any '04 to get ANY love out of that setup. PERIOD. If you want to, after the shims and springs are changed, you can add compression adjustable remote resevoirs(sp) to the upright shocks.
Your #2 idea to rework the rear "linkage" to scissor arms is one way to hurt your chances of actually getting it to work right. It (the '04) was fuuked when it was designed and it was fuuked when it was mfg'ed. The '05 specs improved the situation. It should be only one shim in the stack, plus springs...

The idea to use progressive springs is a good one.

The number two idea was a off the hip Idea I came up with in a fit of rage. HAHAHAHA. the more I think of it I don't like it either.

I talked with another Rider from up here today and he has tried a stiffer spring in the center shock and it made way to much ski pressure. He said that he even had trouble turning at all and the front end stuck to the ground even under hard excelleraation, so I guess I was wrong there also.

I have allready changed the shim stack to match the 05 specs. I guess I'm just going to have to suck it up and go with a progressive rate spring set up.

 

[snowhawk jockey]

I have allready changed the shim stack to match the 05 specs. I guess I'm just going to have to suck it up and go with a progressive rate spring set up.

That shim with the 360 springs will be too stiff. No wonder your having no fun with your ride.

 

[cjgodden]

I didn't say I wasn't having any fun, Cause I have a smile from ear to ear every time I ride it. I just want to get the suspension to work right.

I don't understand whet you mean by to stiff. With 0 preload on the spring It is fine in the small stuff and completely sacks out in the 0-g transfers or large bumps ( like volkswagon size).

 

[snow hawk gal]

Baffling?

Twoskiers reading this have no idea what you are talking about since they would have to be riding a Snow Cross racer in order to hit whoops like any 503F-800 Hawk can!

 

[buffaloHAWK]

i know we are spoiled riding 15+ inches of travel and say were bottoming them out......i am about 185 lbs in the buff so i would say 200 all geared up. in the really whooped out stuff it will bottom easily or off a jump. you have to remember our trails are hard packed and icy,not 2+ foot of powder to take the initial hit.im gonna try this 600 rear skid and see how that goes with stock springs, if still having issues im gonna put my 503 progressive springs on and see where i get....

 

[snowhawk jockey]

I didn't say I wasn't having any fun, Cause I have a smile from ear to ear every time I ride it. I just want to get the suspension to work right. I don't understand whet you mean by to stiff. With 0 preload on the spring It is fine in the small stuff and completely sacks out in the 0-g transfers or large bumps ( like volkswagon size).

Of course you are having "fun", I mean having no fun with the fine tuning of your ride.

Its been a couple of years since I last setup/rode an '04, bear with me. The 280 spring and corresponding shim stack for the rear will allow the spring preload to be set more accurately. Ie, a few turns of preload won't chatter your teeth on the stutter bumps and should hold up better to the deep yumps and buried VW's. More of a happy medium, less a too stiff or slack setting as your only choices. It isn't an end-all-be-all solution. The EX-X still has falling rate and will bottom on big stuff once it gets past 2/3's stroke even with the 360# cranked up. You will be less likely to encounter that if the first portions of the travel have adequite matched spring and valving to handle the terrain.

Sorry for the moto analogy: Same idea as over sprung, heavy valved suspension

It would be like putting a smaller carb(valving) on a motor to decrease flow and get snapper throttle response while increasing torque in the lower rpms. Then, taking the standard airbox(lower spring rate) off and putting a highflow(highspring rate) pod airfilter on to benefit the highrpm horse power. The motor will be difficult to tune well through the RPMs and find a balance for torque and HP because the "airbox" is tuned for the opposite end of the powerband as the carb. If you tune for the torque snap in the low end(no preload) as desired, then the top end will be too lean, falling on its face, and conversely if you tune for the top end(enough preload to keep from bottoming on big stuff) air flow, the bottom end will be too rich and bog(suspension chatter) when we wanted snap...

 

[SnowDunes]

Fox Floats!!

The problem is simple - Falling rate rear suspension needs a progressive spring to compensate - or it is too stiff at first, then it bottoms. Air shocks are massivly proggressive - and will allow for a soft initial travel while become progressivly stiffer.

From tom's snowmobile:

Dan,

We have just about finished analyzing and reconfiguring Fox airshocks to fit into the Snow hawk Expert X suspension. Several options have become available for you. My first option (and preferred) is to use a Float X shock, which is an airshock with additional oil reservoir and single compression adjustment as well as rebound adjustment. At this time we would not incorporate the additional Evol chamber. If necessary we could use the new extra volume bearing inside for additional air volume. The shock would be a bolt in application with the reservoir mounted up. The existing bronze type bushings in your shocks would be reused on the Fox. Retail price should fall at $995.00 per pair, US. dollars.
An upgrade could be available for dual speed compression adjustment but I would prefer to hold off of this upgrade until we are satisfied that this type of shock is what you have been looking for. This also would increase the price of the shock.
A second option would be a standard float at $795.00 but would offer no external adjustment besides air volume.

If either of these packages interests you, let me know.



Tom Dines
Owner
Tom's Snowmobile & Service
530-862-1128 x 10
530-862-1148 fax

I also firmly believe in NOT using the middle shock spring in the deep -after taking it off, then back on, then off again, I beleive It trenches so much more with the middle spring than with out it in place.

 

[Hawkdoggen]

Hey guys , walker evans has built some larger body shocks for fabcraft here in florence , weve got one set waiting on second , the smaller body showed promise last year just , but it just didnt have quite enough in the big stuff . should know in the next few weeks and if they work we will immediatly post and let ya know i just know that after lots of revalving these are already seeming better than the stock shocks by far

 

[snowhawk jockey]

I wonder if those FoxFloats will work for the 503 skid as well? It sure would be nice to firm up the rear dampening past half stroke on mine. It seems to just be spring once I hit past half and bottoms on 2'-3' trail whoops...

 

[TLKDPROD]

The problem is simple - Falling rate rear suspension needs a progressive spring to compensate - or it is too stiff at first, then it bottoms. Air shocks are massivly proggressive - and will allow for a soft initial travel while become progressivly stiffer. ...

How about fixing the problem at the source and relocate the top shocks' top pivot axle?

I'm talking about swapping the shocks pivot axle shaft (that has 2 idlers) and swap it with the idler cross shaft right behind them.

Just a thought... I know it will affect ride height and put us higher up there and get our travel down. But by changing that angle, the suspension would have less leverage on the shocks... allowing the shocks to naturally "be stronger" against the suspension.

I can't wait to try my progressive springs, that may do her. I wish I went with a little more force than 400 at the end.