Congrats on the new ride... just purchased the same sled for my wife. The suspension on those things have a ton of adjustability. I have all her clickers on #1. Rebound set 10 clicks out on the front. Her spring preload / ride height set at #1. For your weight I'd try number #2. Try that as a starter.... keep in mind that although there is only 3 different settings on the QS3R's they are drastic and very noticeable from click to click. Enjoy! [emoji106]


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what did you set the rear rebound to?

 

You have to adjust it for yourself. no two guys ride the same.
Start with the compression, and springs full soft.
with a buddy watching the rear arm at the slide rail, get on the sled and bounce it a couple times. The sled should come to a rest with the rear arm halfway between the front stops, and the coupling blocks. If not adjust the rear springs till it does.
Now you have to ride it.
First use the coupling blocks to adjust weight transfer to where you like it.
You should gently bottom out once or twice a trip. use the compression knobs to tune this.
Use the ski springs and or the mid spring to adjust ski pressure

 

Thanks Krom, this is what I'm looking for.

 

Ideally 2” of sag is the pro cross chassis is happy. Measure at rear bumper and then have someone measure it when you sit on it fully geared up. You adjust for this sag by adjusting the torsion springs and they don’t have to be the same on both sides. Of course everyone’s set-up is different. From the dealer it should have been set up right down the middle on everything but we know how that prep sometimes goes. I’m 180 fully geared and find full soft on all compression, 6 out for rebound on front, 7 out on the back. Two turns tighter on the front shocks and 1 tighter on center shock. Pulled the coupler blocks so I can wheelie when needed over holes and the sled absolutely rips. I have zero issues in the corners with the couplers out.

Good luck! Take notes when you make changes.

 

Taperk600, keep us posted if you find a softer initial rate for that spring. I honestly have not done much digging myself, so I guess Thank You, in advance would be the most polite. :biggrin_old:
I have a RR 137" and that part of the suspension does need some change especially for lighter weight riders. I do like the dual rate, but the stock springs hit pretty hard when the coupler blocks engage the front arm. It should be a smoother transition. I already backed off the spring as far possible. I found a couple of single springs with dual rates but I would like to keep the true dual spring setup.

 

There is an adjustment sleeve between the two springs in the center shock. I have played with that and have my RR handling like a gem.

 

No there is not. There is a fixed plastic "communication ring" that acts as the cross-over link between the 2 springs, but it is not adjustable. Unlike aftermarket ones that are adjustable.

However, the pre-load on the spring system is adjustable same as on every other set up out there. Is that what you are thinking of ? It's not between the 2 springs, but at the base of the shock, under the spring stack.

But even the adjustable cross over doesn't change the initial spring rate. It affects when the spring system couples and crosses from the initial rate to the stiffer final rate. The larger the cross over gap, the longer the spring system stays in the softer rate. The smaller the cross over gap, the quicker it switches from the softer rate to the stiffer rate. But the spring rates themselves do not change.

1st pic is OEM cross-over fixed spacer & is part #18 in the parts diagram

And the other pic is the adjustable cross-over from HyGear shown with their spring kit

 

My experience with the hygear adjustable crossover piece, is that since its aluminum, it will wear out, and will take the shock body with it.
Had one come through the shop, and after 1 season, it was gone, could see right through it between the threads, and the shock body needed replacement as well.

For anyone wanting to nerd out a little bit, the effective rate of multiple springs in series is calculated by:

for the RR, and RS it works out to a 90 lb initial rate, and a 250 final rate. which is exactly the same as every other sled in the line up. Just using 2 springs, instead of a single progressive wound one. (the progressive one on the rest of the sleds has a larger diameter, and will rub on the reservoir)

 

While I have also seen wear on the shock body from the aluminum HyGear type adjustable cross-over, a lot of that wear can be avoided by making sure to align the ends of the coils against the cross-over so that they don't put twisting force on the cross-over. Most people just slap them together and never take the time to do this alignment.

Another, sometimes "simpler" equation is : dual rate = ( rate 1 x rate 2 ) / (rate 1 + rate 2)

And going by the rates listed on the RS of 140 and 250, it does give an effective rate of 90 / 250. But I wonder IF the tender spring is actually a 140 rate or if Cat has listed it by it's "effective" rate in the dual system. But that wouldn't be smart as then any change to the primary spring would throw off the tender spring rate.....so most likely it is the actual rate. It just seems a lot stiffer than the 90/250 in other sleds.

Krom, have you asked Cat if they have alternate rate tender springs ?? I know a lot of their springs, etc aren't widely publicized and sometimes hard to locate without things like the "black and white" catalog or a race sled performance manual..... there is always a bunch of alternate torsion springs, etc in there....

Also, on a conversation you and I had when I was last at the shop..... my 18 has 95# springs on the skis.... the RS has 120#. I remember you commenting that Cat was using 120s across the board. That doesn't seem the case and I'm sure that is also contributing to the difference I am seeing between the 800 and 600.....

 

Thanks for the info guys. I would have never known to align the springs and watch for wear. Lots of knowledge to be had here!

 

Read these instructions. It will show you how HyGear recommends aligning the spring coils along with other useful information.

https://cdn.shopify.com/s/files/1/1208/6906/files/Twisted_Spring_DR_Kit_Rev2.pdf?579593155345847985

 

Ok so it looks like he installed them correctly. So that’s a bonus. Thanks for the help.

 

There are also several less expensive progressive wound springs from cat in the 90-250 range

 

I just popped a Raptor triple rate in mine,worked like a charm!