Shock Valving Change - Aggressive Riding - Snowmobile World : Your #1 Snowmobile Forum

Steve800 · 11-18-2003, 11:20 PM

I want to change the shock valving on my '97 Storm when I rebuild the shocks in a few days. I've rebuilt many shocks in the past, but haven't played with the valving.

Any first hand experience on what sort of change I should expect going from the stock valving to the Polaris "heavy" valving?

The stack setup is (Pol fox shock #7041595 - per the service manual Vol III):

---- Prod.------ Heavy
7C 1.25x.010 1.25x0.10
6C 0.90x.010 0.90x0.12
5C 1.00x.012 1.00x.010
4C 1.10x.015 1.10x.015
3C 1.30x.015 1.30x.015
2C 0.90x.012 0.90x.008
1C 1.30x.012 1.30x.012
Orf. 0.086 0.086
1R 1.25x.012 1.25x.012
2R 1.10x.012 1.10x.012
3R 1.10x.012 1.00x.012
4R 1.00x.012 0.90x.012
5R 0.90x.012 0.80x.012
6R 0.80x.012 0.70x.012
7R 0.70x.012 removed

The heavy valving in rebound doesn't seem to make sense to me. I would expect you require more or stiffer valves in order to increase the damping.

If you look at the recommended compression setup, it seems to make sense. Having the thinner 2C will let 1C hit 3C sooner and the stiffer 6C makes sense.

If you look at the recommended rebound setup, the heavy removes the 2R, which I would expect would make it softer.

What gives? Am I missing something?

Steve

Steve800 · 11-18-2003, 11:26 PM

Argh... For some reason SW only allows a single space between text characters, screwing up the table....

Hopefully you guys can figure it out.

Steve

Steve800 · 11-19-2003, 12:31 AM

How about this for another question.

Anyone ridden a 1998 (or 1997) XCR440? Is the rear damping excessive?

It looks like its got more in-line with what I think I'm looking for. Here are the numbers for it compared to my 97 Storm (98 XCR440):

---- Prod. ------ Heavy ---- XCR440 -- XCR Heavy
8C not applic. not applic. 1.25x.010 not applic.
7C 1.25x.010 1.25x0.10 0.90x.010 1.25x.010
6C 0.90x.010 0.90x0.12 1.00x.012 0.90x.012
5C 1.00x.012 1.00x.010 1.10x.015 1.00x.012
4C 1.10x.015 1.10x.015 1.25x.010 1.10x.015
3C 1.30x.015 1.30x.015 1.30x.012 1.30x.015
2C 0.90x.012 0.90x.008 1.00x.006 1.00x.006
1C 1.30x.012 1.30x.012 1.30x.012 1.30x.012
Orf. " 0.086 " " 0.086 " " 0.072 " " 0.075 "
1R 1.25x.012 1.25x.012 1.25x.010 1.25x.010
2R 1.10x.012 1.10x.012 1.25x.010 1.25x.012
3R 1.10x.012 1.00x.012 1.10x.012 1.10x.012
4R 1.00x.012 0.90x.012 1.00x.012 1.00x.012
5R 0.90x.012 0.80x.012 0.90x.012 0.90x.012
6R 0.80x.012 0.70x.012 0.80x.012 0.80x.012
7R 0.70x.012 not applic. 0.70x.012 0.70x.012

Again the heavy setup looks a little odd, especially with the smaller orfice (which I would expect would have a fair bit of effect on high speed damping).

Could someone post the stock valving for a 1998 ZR500. A friend of mine has one and and the rear damping is quite nice (of course the suspension geometry won't be exact).

Steve

Smoothride · 12-04-2003, 05:42 AM

Why do you want to change the valving? Rebound usually doesn't need to be changed unless you are changing spring rates or have a problem from the begining.

Steve800 · 12-08-2003, 12:34 PM

Quote:

Originally posted by Smoothride@Dec 4 2003, 05:42 AM
Why do you want to change the valving? Rebound usually doesn't need to be changed unless you are changing spring rates or have a problem from the begining.

There is way too little damping for my weight and riding style. Even with the heaviest rear springs on the highest setting and the front track spring cranked way up I still bottom it out regularly (even with freshly rebuilt shocks).

My goal is to run the sled 3" lower and use the shock to take the landings (after the suspension goes into full droop).

I'm sure it can be done. My buddies ZR has softer springs, but much better bump control and resistance to bottoming.

Anyway, I ended up ordering a custom valve assembly from Carver Performance. It should be here tomorrow.

michahicks · 12-08-2003, 03:22 PM

Steve800, Just a couple ideas now that I see what you are trying to accomplish.
The Edge suspension offers a couple of adjustments you could use about now. Don't have an Xtra near to see if it will work, but both amount to extra holes drilled in the rails. At 6'2"/280 I'm no little guy either, and can relate.

The Edge has multiple holes for the lower mounting position of that rear rocker. If possible, you might consider moving your pivot point back an inch or so. This made a huge difference in how the springs handled my weight. Now using low and medium settings on the adjuster cams, using standard springs. This also affected transfer big time. It will let the rocker contact the RRSS sooner, amounting to less sag before it does so. Both worked out pretty well for me and my riding style.

The other adjustment I just started playing with. The nylon roller that caries the front of the rear spring. Again, the Edge has multiple positions available to mount it. If it is moved to the rear, you will also increase the spring rate...

Don't know if you want to mess with this or not, but figured it might be an option about now.

AL

Powerband Racing · 12-11-2003, 11:12 PM

The first thing to learn with valving is Low speed is your weight/ High speed is your riding style. Also when looking at a valve stake remember that shims can only bend so far. I don't usually give out valving, but this is a good start for you.

Rear Shock Valving at 200lb Novice
1.000 x .015
.700 x .012
.800 x .012
.900 x .012
1.000 x .012
1.100 x .012
1.250 x .010
.800 x .008
(3) 1.250 x .010
-----PISTON------
(3) 1.300 x .010
.900 x .008
1.250 x .010
1.100 x .012
1.000 x .012
.900 x .012
.800 x .012

Remove (1) 1.300 x .010 and add (1) 1.300 x .008 for 180lb rider
This will work 100%

Powerband Racing 763-263-8829

Steve800 · 12-17-2003, 08:40 PM

Thanks for the suggestions. As I noted above I did order a valve assembly from carver performance.

Just a little more snow and I'll be able to test it out...

Steve800 · 12-27-2003, 08:41 PM

Quick question for you guys.

As we still don't have any snow I haven't rushed to get the new valve assembly installed.

So, just now I pulled the suspension out and took apart the rear track shock. To my surprize the "stock" valving isn't at all what's listed in the shop manual. It looks like a valve stack from an older machine - constant reduction in diameters farther away from the piston.

There is a 1.125" x 0.100" washer as the 6th valve away from the pistion. The new one (from Carver) looks more like what the newer sleds are running (and my sled is supposed to be running) - varying between larger and smaller diameters throughout the compression stack.

Anyway, the question. Is this still used when going to the new 8 compression valve stack? This would make it the ninth washer from the piston.

Steve800 · 12-30-2003, 11:19 AM

What a difference. Although there's still no snow so I can't try it out, even with the springs on the lowest setting I can't bottom the machine out if I jump on it - even using the rear bumper.

It feels very nicely damped. I used to be able to bottom it out with the springs on the highest setting (had to really use my legs to keep it from bottoming out when sledding).

This weather sucks! It's pouring rain again.

The original main rear shock had the following (not at all what the shop manual lists):

5C .7x0.008
4C .8x0.008
3C .9x0.008
2C 1.0x.006
1C 1.3x0.008
Orfice: 0.067"
1R 1.25x0.008
2R 1.1x0.008
3R 1.0x0.010
4R .8x0.008

I don't know what Polaris was thinking with that setup, but looking at it - no wonder it felt like there wasn't any high speed damping. There wasn't any!

While I rebuilt the front track shock I decided to follow the same approach and tweaked it to follow Carver's trend for the rear track shock (similar to the stock '98 XCR440, with a little softer 1st stage in the multi stage stack). The front track shock did have the stock '97 Storm valving.

If any of you think your stock sled seems a little undamped - check to see what Polaris (or whoever) put in there. You might find the answer.