Suspension 101

hmmm very intresting...the only reason i have ever adjusted my CENTER shock and tightened the spring was due to bottoming...with my old zr's (98 and 02) both with the remote resivors) i talked to a guy that does a lot of racers set ups and told him about my problem and he tightened up my center shock about 1/2 inch and it made a lot of differnce...right now i have my firecat SP set at 3inches of threads showing...thats what ive adjusted it..thats the only time ive rode my sled was with that setting..i thought it was fine BUT..it was almost 50 degrees and snow was packed and loose...so going back to robs original post what AC said..maybe for warmer days ie spring time riding..a tighter shock may be better...

I found VERY intresting that they said with it to tight.. on the wrong conditions u could loose from 5-8 MPH on the top end because its not plaining out enough...whichi found intresting because although the snow was sticky that day and didnt do much for high speed runs..on the same streches my buddy could get his F7 SP up to 108..and mine i would get to 103-104..he hasnt touched his suspension... i think i will try it..but im just affraid in the moguls when u crack the throttle at the base of a mogul..that that center shock will bottom..or maybe it wont bottom any worse then with loose ski pressure..i think that is the most significant shock on the sled...i hated my sled last year because it would alwasy bottom out on the center shock..but at the time i was 260lbs almost..so weight has a lot to do with it..but this year im under 220 now and the woops section i did find it did not bottom out on the center from what im used to remember...its gotta be a trial and error thing... im sure revalving the center shock is also an option?? but then it would throw off stuff again ?? haha AHHHHHHHHHHH confusing

Last years ZR with the coupled suspension, when adjusted correctly, set a new standard in great handling, and did so in all conditions. So what has changed?
First, I think you will find chassis height higher in the F-Cat. This is a big negative. Especially higher chassis height in the front end.
Secondly, the ZR had soft ski springs and as the front end started to twist in a corner, the stabilizer bar came into play. It appears the ski springs on the F-Cat are stiffer. I am guessing Cat used stiffer springs to curb ski lift, which may have been a mistake. This gave rise to chassis height and stops the sway bar from doing its thing.
Third are the skis. Yami has changed their ski design whenever they changed the chassis. Doo failed to do this going from the S chassis to the XZ chassis and ran into all kinds of handling problems until they matched a ski to the chassis. Just a theory but I don't think the skis match the chassis and you will be able to dial in okay for one condition, but not all. I believe Rob stated this a few days ago, feeling the sled handled fine on hard pack but was impercise on chewed up snow.
Fourth is wheel base. I haven't compared, but I am betting it is different from the ZR. It sounds like a shorter wheelbase based on some of the things that have been said about handling. I am talking from spindle to where the front of the track meets the snow.
Next, I am going out on a real long limb here, but I am starting to think there is an engineering flaw. Just a minor one, but the reason you have to sit on the gas tank for precise handling and why it doesn't handle as well in chewed up snow. I think the entire front suspension is not bolted in to the correct position on the chassis, and this is two pronged. It may be bolted in too high and also too far back. Thus the wheelbase is too short And the suspension does not go down far enough to make the correct ski pressure at the ground. All this talk of centered mass, getting the sled to pivot instead or turn!!! Maybe we have lost the balance of an engine in front and a driver in the rear balancing things out.
Does this make sense?
mike

CAREFULL, while expiermenting with my sled this weekend, i loosened the front track spring all the way!!!. I have a sno pro, so it may matter, but you need atleast 1 1/2-2 inches of thread showing in order to get any preload on the spring at all! I was able to looosens it a good inch or more before i realized i was at full soft, after that, you can actually shake the spring and wriggle it around which is bad. You must have some tiny bit of pressure on the spring other wise it will mess the shock up bad. Imagine coming over a big bank and having a loose spring jam agaisnt the shock and bind the bodies agaisnt the mounts. oh4: as you loosen it try to shake it constantly to make sure theres is abit of preload on it. it does go nice with a soft front shock and no couplign blocks with the strap sucked up 1 position. Funny thing is, on a 2003 standard, you only need 1/2 inch of thread to have some bit of preload on the spring? Dont know why? funny thing. So dont loosed to the point of actually loosening the spring off the body :flag_usa: