Suspension 101

6258 Views 60 Replies 36 Participants Last post by riverrat, Dec 28, 2003

rob

Discussion Starter · Dec 17, 2002

I got to thinking about setups and all.. and it occured to me that perhaps some of you think of the front arm as just another spring, and 'don't want it too soft' because you 'like a firm ride'.

The front arm is basically a pivot point for the entire suspension, and if it is too firm, the entire suspension can be compromised, not just in ride quality but also performance. A too-stiff front arm will hurt deep snow performance as well as top end. There are only a few conditions when a stiff front arm is desirable. And I'm talking in general here, not just with the Firecat.

I also took a look at the AC performance manual that I received from Dan at the Outdoor Shop to see what it had to say about the front arm setting. I found what it had to say so interesting that I copied it and posted it here. Again, this is from the Cat performance manual under "Suspension Setup Basics", and it basically agrees with what I've said for years:

21 - 40 of 61 Posts

Captainkev

· #21 · Dec 17, 2002

Great info to all concerned. This would probably explain the less than positive feel I get on the skis when I decelerate.

OK, new list for Friday Night:

1. Studd the SnoPro Track....................no more flips allowed unless planned

2. Lighten pressure on forward spring ........never checked it

3. Put on all my sledding gear and do the snow dance........................fortunately my cabin is in the woods so no one but my family will see the dance, and they already know I'm a little snow crazy.

:wacko: :wacko: :wacko: :wacko: :wacko: :wacko: :wacko:

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rob

Discussion Starter · #22 · Dec 17, 2002

All good posts, AG.

What are your thoughts about the limiter strap position and the coupling blocks, and how they interact with one another.. Is your Cat coupled?

NYF5

· #23 · Dec 17, 2002

Rob,

This is good general Info. Can this post be pinned, or at least post your part from the manual and AG's posts?

Captainkev

· #24 · Dec 17, 2002

Along the lines of the coupling blocks. I moved mine to #2 to get some forward weight transfer to help with the front skis. Now if I adjust the spring a bit looser, it sounds like this has a somewhat similar effect.
I am wondering if then I can go back to # 1 for less transfer.
Any thoughts on this ?

Kevin

Nick

· #25 · Dec 17, 2002

AWESOME INFORMATION GUYS! My shock has about 2" inches showing as well. I will have to adjust it before I ride next week. I can't even wait!!!

Said it before and I'll say it again. Gotta Love this forum!!!!!

rob

Discussion Starter · #26 · Dec 17, 2002

Originally posted by Captainkev@Dec 17 2002, 04:43 PM
Along the lines of the coupling blocks. I moved mine to #2 to get some forward weight transfer to help with the front skis. Now if I adjust the spring a bit looser, it sounds like this has a somewhat similar effect.
I am wondering if then I can go back to # 1 for less transfer.
Any thoughts on this ?

Kevin

when you say transfer, it generally means transfering weight to the rear suspension, and the #1 setting on the coupling blocks transfers weight to the rear the greatest. #2 less transfer and #3 least transfer of all (and most weight staying on the skis). With the block in #1 I was pulling the skis two feet in the air. #2 only 1 foot. #3? I'll try that next.

messickzr

· #27 · Dec 17, 2002

Rob, I have read that you adjusted the front arm shock on your F7. Did that do anything to combat the ski lift that you are reporting. What else (besides looking at changing the coupling blocks to 3) are you going to try? On my 1999 ZR I moved the rear arm back one hole and made some minor adjustments to the IFS springs and the front arm spring. Made the thing corner on rails. Have you moved your limiter strap yet?

rob

Discussion Starter · #28 · Dec 17, 2002

Originally posted by messickzr@Dec 17 2002, 05:23 PM
Rob, I have read that you adjusted the front arm shock on your F7. Did that do anything to combat the ski lift that you are reporting. What else (besides looking at changing the coupling blocks to 3) are you going to try? On my 1999 ZR I moved the rear arm back one hole and made some minor adjustments to the IFS springs and the front arm spring. Made the thing corner on rails. Have you moved your limiter strap yet?

Yes, backing off the front arm shock made a big difference in the way the sled handled.. especially when combined to moving the transfer blocks to #2 and lowering the IFS preload and aligning the toe. It still lifts skis, but more in a fun way now. Next time out I will move the blocks to #3 and then posssibly try shortening the limiter straps as an experiment. I'm doing changes rather slowly to be sure that I have a handle on things. At first I just wanted to get seat time, now that I'm totally confortable on the F7 I will experiment more. I do find the light Firecat chassis reacts to minor changes in a big way. That's probably why it's a little harder to dial in than heavier sleds.

Captainkev

· #29 · Dec 17, 2002

wow !

f-5snopro

· #30 · Dec 17, 2002

i have a question, how will the sled land after going off a jump with light spring tension?

rob

Discussion Starter · #31 · Dec 17, 2002

we'll see what AG says, but I don't think it would make any difference at all. You are landing flat or on the tail and the front arm really doesn't even come into play in those situations.

Craig388

· #32 · Dec 18, 2002

Holy S&^t, I'm eating this up! Thanks A G.

rev them up

· #33 · Dec 18, 2002

How many inches of thread is showing on the front(ski's)of ur
guy's st f7??mine came with 2 1/2 inche's shown.I brought it
down to 2 inches......so what rob and other's are saying to
try are crank it down untill there is just enough spring tension
to seat the spring...correct??Also do this with the front skid shock also
correct??

madmike

· #34 · Dec 18, 2002

damn,so much info my brain is on overload,,

czy42strokes

· #35 · Dec 18, 2002

ouch.....

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rob

Discussion Starter · #36 · Dec 18, 2002

Originally posted by rev them up@Dec 17 2002, 07:59 PM
How many inches of thread is showing on the front(ski's)of ur
guy's st f7??mine came with 2 1/2 inche's shown.I brought it
down to 2 inches......so what rob and other's are saying to
try are crank it down untill there is just enough spring tension
to seat the spring...correct??Also do this with the front skid shock also
correct??

...WITH the sled elevated.

The reason for that is so you don't lose the spring retainer when the suspension drops out fully.

green team7

· #37 · Dec 18, 2002

Wow...never before have I been this informed about a snowmobile!!!

gatsledder61

· #38 · Dec 18, 2002

Rob - Great post, thanks. The AC performance manual talks about soft snow conditions. Conversley, can we expect better performance (cornering) by putting more spring tension on the front shock when riding on ice conditions, such as river riding? Where we ride, a premium is placed on handling through the corners, not corner to corner acceleration. I have adjusted the limiter straps up by 2", and plan to put spacers in the front shocks to lower the front end. What do you think?

Thanks,
Garry

Nhpatriot

· #39 · Dec 18, 2002

Backing off the front skid spring has always been a setup check for all my cats.

Nick

· #40 · Dec 18, 2002

Rob, I think we should pin this post! Excellent Information in here!

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