lets talk rear suspension

[off road rider]

Ok guys lets beat this horse down..
TLKPROD and sleder2 both have made changes or complete redesigns..
are you guys interested in supplying parts or info for others??
My motor build is 1/2 done, next is to tackle the ratcheting and rear suspension.
how about listing the diff between the models and why they are lacking, what should be done or options..
I actually like the suspension on the 503, but the ratcheting has to go..
pivot relocation or a complete redo??
from what I saw last year the zx2 would not be considered an upgrade, quite the opposite..

 

[cjgodden]

the problem with the rear suspension is the "falling rate" design and the fact that as the suspension moves through its travel the track tension changes. IMO the easiest way to stop the ratcheting is to run extroverts and run the track tension as loose as possible. That will stop ratcheting and the stress on your other systems from the track becomming to tight in the travel.

The more complex option is to work the pivot points to a position that the track tension does not change throughout the travel. I don't think anyone has done this with the expert suspension that is under the 500 chassis. The expert X that is under the 600 and 800's has been tested with a relocation plate that is availible. I got mine from Sledr2.

The other problem is the falling rate design, as the suspension moves through the travel the last 1/2" of shock movement has almost no force to prevent bottoming out. This is why TLKD wants to make his own progressive rate suspension. The falling rate design can be masked with dual rate springs, and valving, but it will take a good suspension tuner some time and effort to get it close and it will never be perfect.

 

[buffaloHAWK]

id like to talk too

i have a 503....too soft stock. so i put the awfully stiff 2004 600 skid back there. better but very harsh for the 1st few inches of travel,then bottoms as the stock skid does...i hear there is a relocating kit for the 600 but where would i relocate it on my 503?

 

[TLKDPROD]

Here's what I have to say on this : "Strategically relocate the upper swignarm pivot, upper and lower rear parralel bar pivot as well as going with different length for the swignarm and rear parralel bar will get you going without the ratcheting issues !"

It's only a matter of finding the proper pivot arrangement for the setup you have : rail and rail extension profile, rear idler wheel size, track driver size and track length.

What I did when I designed mine was I made sure that I had the same theorical track length, at rest, half compressed and fully compressed. I don't know if a guy could end up being at 0 perfect (no track tightening, no track loosing). Mine is within 0.040" on 150 inches. I called close enough. Sometime you'd only relocate one pivot within 1/8", resimulate it and screw it up by five times this amount.

Do you need a complete redesign to get rid of track tightening ? I don't think so (If you were to fight the falling rate leverage ratio then it would be different). You can keep your rail setup that's for sure (even though I'd suggest going 8" on the rear idlers). Keep the plastic part of the rear parralel bar. You need a new pair of swignarms that are gonna be longer, (you'd keep all the stock pivot parts though), probably a new rod for the plastic rear parralel bar (that will match the measurments of whoever's gonna do the engineering on this...), 2 brackets for the frame and probably 2 others for the rails (for the lower parralel bar pivot relocation).

I'll try to throw a few lines tonight since i'm waiting on some parts and have nothing left to design except my personnal upcoming graphic kit. That will sure adds at least 7 or 8 MHP (Mental HorsePower) but i'm not too worried about it for now

 

[off road rider]

understand the geometry issues.. my 503 has the expert X suspension..two shocks.
Doesn't a 6 or 800 have three shocks??
theres also the spring issue. Where can we purchase different rate springs for front and back??

 

[cjgodden]

Expert has two shocks, expert X has three shocks.

 

[off road rider]

Expert has two shocks, expert X has three shocks.

huh.. I have expert X stickers

 

[cjgodden]

That the way I understood it, but then again we are talking about adbovion.

 

[snowhawkaddict]

BNG's

Expert X, then Expert Xtreme, I just looked at them both in the garage, almost tripped over that new 2Moto!

 

[cjgodden]

AHHHHHH oh knowledgeable one, I understand my mistake. Assumption is the mother of all misunderstandings. I assumed the X stood for xtreme therefore expert x = expert xtreme, I stand corrected.

P.S. went out in my shop to look also, but my stock stickers are covered by my TLKD graphics. LOL